Hagenuk HA5K39a with Feldhell Mode.

NEW!

This is my new German radio. I purchased this radio in oktober 2023, by an exchangement with another radio.

The Hagenuk HA65K39a is a German navy transmiter receiver, which is used on small navy ships or at a naval base on mainland.

It has a seperate receiverpart and a seperate transmitterpart. The receiver is a TRF receiver with only one HF stage, a regenerative detector and one LF stage. All tube types RV12P2000 . The transmitter is a two stage transmitter, with a RL12P10 as a final amplifier. One modulation stage, also acting as a tone oscillator for MCW and sidetone for CW. Tubes are RV12P2000. A stabililizer tube for 150 volt. GR150A.

Provision has been made to tune in the transmitterfrequency to the receiverfrequency.

The modes are phone, CW en MCW. Power is 8 watts on phone and 10 watts on CW

Below the Hagenuk HA5K39a.

Left the receiver and at the rig.ht the transmitter

Below the powersupplies for 300, 200, -50 and 10 volts DC. Also for 12 volts AC. The 200 volts DC is stabilised with a EL84 tube.

Plans were made to make the radio suitable for Feldhell Mode. Normally the a version is not suitable for Feldhell Mode, the versions b and c do.

So I had to make a small change in the internal transmitter part.

The picture below is the change in the schematic diagram.

The main changes in my A version to be done, is to be seen in the diagram up, is:

1 – Desolder the kathode connection to earth.

2 – After disconnecting one of the telephone connection at the front, Solder a wire from the kathode of the PA tube to that disconnected telephone connection. This connection is to be used for the drum contacts of the Hellschreiber. So from the Hell connection on the wsitchbox two wires to that the disconnected telephone entree.

3 – Make a switchbox with a switch for bypassing the CW key connector. Make 2 wires from the normally open contact of the witch to the key input on the front. Switch contacts closed >>> transmit, switch contacts open >>> receive.

4 Switch (Betriebschalter) the mode on the HA5 to CW.

Now the HA5K39 a is suitable for Hellmode. It is a kind of kathode keying of the transmitter poweramplifier by the Hellschreiber drumcontacts, just in the same way, done in the B or C type version of a HA5K39. And it is safe. The contacts of the drum must not exceed 100mA or 150 volts DC. Better some less. So the current now at key down, is about 55 mA at a voltage of 0 volts (kathode keys to earth).

Picture below the front of the Hellschreiber with the connection panel. The big connector is is a homemade one with two contactstifts, to pin 3 and 4 of the Hellschreiber.

Picture below the front panel on the HA5K39. The connector is a homemade type, not done by myself. Also the switchbox with the switch for transmit or receive. Below the connection to the drum contacts of the hellschreiber.

Picure below some received text on the paperstroke of the Hellschreiber. A qso with PA0AOB, Arthur, PA0KDF, Koos.

Below my first test transmission in Hellmode with the HA5K39. A screen of decoded Hell text .BY the PC programm of IZ8BLY. Monitored myself at the websdr of Maasbree. Beautiful thin charactors. That means that the 900 Hz pulses are very well.

Below picture is a reception of my Hell Mode signal from Helge Fykse, LA6NCA in Larvik Norway. That was at 15:00 hr GMT with increased propagation, during the Hell net. My transmitter was the Hagenuk HA5k39 a with 10 watts. Ofcourse I used the Hellschreiber too.

I was a bit proud of it. My report was 456 rst. Not bad at all. Distance about 900 km straight on. Also Arthur, PA0AOB had a good signal.

Ofcourse lateron there appeared some troubles. But I fixed it all. One was, that the frequency of the transmitter drifted quit a lot. About 400 to 600 Hz. That is to much for Hellmode.

And why?

The problem with radio tubes in free running oscillator stages, is the the warming up of the tube. The heater and anode/screen current warms up the tube. Because of that the so called anode capacity and grid capacity are increasing. Bij warming up the electrodes , like anode and screens, the material of it expands. So the capacity to earth is increasing. This capacity influences the resonance frequency of the various coils. So frequency will decrease.

But especially when there is a high anode and screen current, this effect is increasing. So you have to make the anode and screen current as les as possible. Then warming up gets less. The RV12P2000 has a 12 volt heater, so gets pritty warm, even if there flows no current in the tube. If the heater should be 2 volts, then you get almost no warming up of it.

In my situation:

There are two ways for warming up the oscillator tube:

1 – warming up by the heaters.

2 – warming up when the oscillator is working.

The first cause cannot be avoided.The heaters must have supply. So always a warming up.

The second cause is only happening when key is down during CW Mode.

During receive in CW Mode, the anode gets constantly HT supply, a little anode current is flowing. The sreen gets HT supply during key down at transmitt. but the waming up of the tube is less, so the frequency drift. Increased current will flow at key down (transmitt). During key up (receive), there flows a little current. So is increasing during key down. So warming up and so frequency drift, is during more by key down.

I decreased the drift first by increasing changing the screen resistor of the oscillator, a RV12P2000, , from 12 kohm to 47 kohm. The voltage on the screen went from 123 volts to 100 volts. The screen current from 4,7 mA to 2,5 mA. So the anodecurrent is decreasing at key down.

Second I placed an extra resistor of 15 kohm in series with the ande of the oscillator tube. The voltage decreased from 197 volts to 152 volts. The anode current is now 3,8 mA, less then with the original value of this resister. The oscillator is working still very well, so the start up is. But the drive energie for the PA is some less. The total warmingup has been decreased a lot. So the drift of the frequency.

The drift is very acceptable, because of those changes. Especially increasing the anode resistor did influence the warming up/frequency drift.

You should expect that the power output of the transmitter would be much less. Because the oscillator output is less by the decreased anode current. But the power output of the transmitter is now a little less, about 9 watts instead of 10 watts on CW. But sufficient.

Ofcourse you have to hold on a warming up period of the transmitter, say a half hour to stabilise the the warming up of the oscillator tube by the heater. After that you start to activate the transmitter. And with the precautions of above, you will get the most stable frequency in Hell Mode.

Restauration receiver LO6K39.

Recently, I  perchased a  LO6K39 in very bad condition, uncomplete condition. It came with a seperate case, case frontcover and  a spare coildrum.

The receiver was bought by the former owner in de 1980’s and was “modified” by him. Like many surplus radio was done at that time.  A whole unit with LF-, a part of the detector- en CW filter stage  was removed. What a pity. Some mods are not always better.

Instead of it, some new hardware was added.  All this with integrated circuits etc.  There was no documentation with it. So a lot of work, finding it out, what it was and how it was functioning. But making a new circuit diagram, how it was functioning, was too much.

So I removed all the new hardware. And was finding out, where all the wiring was going to.

Also the frontcover was missing, so the voltmeter on the front. All original knobs were missing, so the mainswitch too.

But I decided to give it a try, to let it work again.

In the pictures below you can see the transmitter, when it came to me.

LO6K39 Ton B

The front without the cover. Watch the big square hole in it, where in normally the “on/off”switch and CW filter was placed, all removed.

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The inserted new hardware with the PCB’s and integrated circuits.

First, I cleaned the chassis from all dirt etc. It was very dirty, it was in backstore more then 30 years.

The coil drum was not rotating at all. Much hardened grease between the geer wheels. I had to clean them, took a lot of time. In most german equipment that grease is fully hardened and have to be removed. New grease had to be added.

Next,  I had to add some missing parts of the detector stage and a new LF stage. The detector stage with a RV12P2000  tube and the coils were there already.

In series with the anode I added the missing  HF choke, and a LF choke to the high tension voltage and some decoupling condensors.  By lack of the original components, I used the primary side of a little AMROH LF output transformator and a little little ferriet  choke, suitable for the used frequency. The HF choke for preventing  HF energie to the LF stage and the LF transformer to get the LF info for the LF amplifier.

A new LF amplifier with a RV12P2000 tube. Just in style.The input conected by a 10 nF capacitor to the hot side of the LF choke.  The circuit is the same as seen in the circuitdiagram of the LO 6K39. Only no 2000 ohm secundary side, but a 8 ohm one.  Proving just enough gain forthe use of a headphone.

I made a new frontcover for the receiver. Also a new antenna post was made on the front.

Now I inspected the powersupply, which seemed to work well.

The mains power cable was connected directly on the entrance behind the receiver. Maybe I will put a switch on the cover. But I hope once to get another original unit. However hard to get.

I switced the receiver on now, but nothing was to be heard, no noise or signal.

After examing it all, there was no HT on the anode and screen connection on several tubes.

So I cleaned the contacts on the coil drum, I readjusted them for making good pressure contact on the drum and tried it again. I also inspected alle the coil units too.

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The contacts of the coil units of the drum. The 5/VI K  on the coil unit means: 5-th frequency band,  coil stage 6( detector stage), K for “Kurzwellen” (shortwawe) Showing an L, it means a coilunit of a Long Wave receiver LO6L39. And not suitable for shortwave.

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My spare coil drum. Above the revolver mechanics.

The receiver came alive at bit.

Now I noticed the detector stage did not oscillate in CW. It seemed to be something wrong with the resistance of the anode coil in the detector coil unit. I was lucky, because I had a spare one from a seperate spare coil drum (picture above). After replacing it, I saw it oscillating on my oscilloscoop instrument. But still no extra noise in the haedphones. It seemed that it was not on frequency.

For instance, when you tune the receiver in on 3600Kc, the detector must oscillate in CW also on 3600 Khz.

So I putted it on frequency. With the help of a frequency counter. Now a lot more of noise in CW.

I connected now a RF generator to the antenna post and setting it at 3600 Kc., with very low output of course.

I retuned al the HF stages of the receiver, by measuring the LF info at the LF output stage.

Now I heard various CW signals . Even SSB. The receiver was working again.

Only without a nescessary CW filter in it. The “Tonsieb”. It is in the missing unit.

But maybe in future I will add one?

It was a nice project doing it. It took a lot of time, but I was very satisfied about it.

The new frontcover , and the receiver in its case.

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Side view receiver in its case

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The new LF amplifier with the RV12P2000

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Just right above the LF output transformer, Right below the RV12P2000 tube and left below the LF transformer as a LF choke.

Bendix aircraft transmitter TA 12.

The Bendix transmitter TA 12.

TA 12 front 2

This transmitter is originally an American made aircraft transmitter, but also used in the British Royal Airforce (RAF). Aircrafts like Mosquitos.

The  TA 12 has four frequency bands, one for longwave and 3 for shortwave. The funny thing is that each frequency band,  has it’s own VFO,  and only one poweramplifier for all of them, but again 4 output tuning filters with variometer inductance, to match it to the antenna. It delivers about 40 – 50 Watts on phone and CW. Modulation art, A-G2 modulation. In the mid the earial current meter.

The four knobs at the left are the channel preselector tunings, for each wave band one. Left of the knobs are the channel numbers you preselected. In the mid under you can see the knob for preselecting one of the four wave bands.

At the right are the four knobs for tuning, by variometer inductance,  the output filters for matching the transmitter to the antenna.

In the beginning, by lack of the original powersupply/modulator unit, type MT 28 BA , I used a separate modulator, homemade, with 2 valves 807 in the final.  With Ronette crystal microphone. It was doing very well. Also a homemade mains powersupply is used.

But some time ago, I managed to buy one on EBAY, a MT28BA. See the pictures below.

Bendix_MP-28BA (1)

Sideview with power connector.

TA12 DYNO

Inside view with at the left the Audio PA amplifier valves, in the mid, the modulation transformer.

TA12 DYNO BOTTOM

View components, at the right, the several fuses and the switch for switching from carbon mic to dynamic mic.

The unit had to be cleaned a bit and inspected.  But  nothing was wrong with it. The unit came also with home made cables and control box for working with the transmitter on AM, CW and MCW. For AM I used a T17 carbon microphone. Modulation deph 100 %. The noise level of the rotary transformer is not to heavy. It starts only at CW (contineously) and at AM (during transmitting).

Behind a small panel, you can chose by a switch, between a carbon mic or a dynamic mic. Note that at a type MT 28 B, this provision is not available.

Inside the transmitter.

TA 12 upper

The upper view of the transmitter.

The box at the right is the VFO compartment. At the left upper, one of the four variometer inductances, four each band one.

TA12 relay

View at the HF power amplifier with relay for switching the antenna and HT to the amplifier. The 2 tubes are in parallel.

TA 12 under

The under view of the transmitter. The motor for automatic channel switching at the left is missing. At the right, the VFO box again.

TA12 side

Side view with the four tubes of the seperate VFO parts. Each frequency band  has it’s own VFO part, so also it’s own tube. Left up the power input connector.

The modulator unit is doing very well. In mode AM, I can make almost 100 % modulation depth.  On CW, the tone is very stable. A pleasant way of working with it.

German directionfinder Peil G6.

Direction finder receiver EZ 6

“EMPFÄNGER ZIELFLUG”

Overall description of the receiver as a direction finder.

This is a receiver, part of the Geman “PEIL G 6” aircraft installation called  “Peil Gerat 6”.

It was used for navigation/directionfinding purposes in large aircrafts like the Heinkel HE 111, Junker 88 and so on. It was common for EZ6, to be combined with the Fug 10, where it would have been placed instead of the E10L receiver. This was called the Fug10P (Peil).

There are 3  frequency bands: 150 -300 Kc, 300-600 Kc and 600- 1200 Kc.

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Photo above: front of the receiver

  • Upper left knob: A2 is AM, Eich is calibrating the frequency, A1 is BFO is used by navigating, Bandbreite is making the MF smaller.
  • Upper right knob: Entrubing is cleaning the signal from “humm etc.”
  • Middle knob: tuning the frequency.
  • Lower left knob: gain controll.
  • Lower right knob: arrow is navigating by a double needle instrument type AFN2. Circle is Rund Empfang, frequency band 300 -600 Kc. Communication purpose as a replacement band for the E10L.
  • Lower middle: connection for headphones (left) and test entrance for test meter PV10 for measuring the internal voltages.
  • Small upper right panel: Behind the trim pot for calibrating the frequency scale.

The inside of the EZ 6 receiver.

Note the text on the pictures for removal of the various part blocks and connections.

 EZ-6 003a

The front with cover panel removed.

EZ6b 012a

The block units from the receiver from behind.

EZ-6 010a

A connector of a unit.

EZ6b 002

EZ6b 010

Here to be seen the contacts of band switch.

EZ-6 015

EZ-6 020a

EZa-6 001

To the right, the opened oscillator unit.

OSCb 001

Oscillator case with pcb circuit removed.

OSC 001a

The removal of the oscillator pcb, a fully ceramic plate. The green points are the data, where the wires, comming from behind the ceramiec plate, have to be

desoldered.

OSC 004

The three wave band coils of the oscillator. Above in the picture, the metal cover of the coils.

OSCc

The three coils explained.

OSC 001b

The connections of the coils, the grid, anode and coupling coils. Very handy for measuring the coils.

Temperature compensation to stabilise the frequency of the oscillator circuit of the EZ 6.

All the components of it are mounted on a ceramic plate as a printed circuit, which was very revolutionair  in that time, nowadays very common. This has a very good effect at changing wiring capacities, due to warming up of them. Also mechanically very stable to heavy shocks.

Other provisions were these ceramic condensers in parallel , which have all a different temperature coefficient control. When they get warmed up by the air in the small cases of equipment, their capacity values changed that way, that frequency stability of the oscillator is improved.

These special condensers, you can see in the picture above, the green and brown condenser blocks.

On the printed circuit plate of the oscillator ceramic plate in the left side of the picture above, you see these green and brown  condenser blocks. All ceramic  condensers, in parallel, are placed over the the inductancies  in the circuitry.

About these condenser blocks, there was another type with ceramic ones with different specifications . Different from these of the temperature coefficient types.

It is so special, that I like to tell something about it.

One is a special, great type of ceramic condenser, which proof the great knowledge of German engineers in that time. Consider, it is now more then 70 years ago!

These were made by the German manufacturer Hescho, who patented it, and made also the ceramic coils holders and variometers.

The ceramic condensers are very special made. In fact, they are very bad condensers with a big dielecric loss with a particular temperature coeficient.

The principle:

Let us look at the internal capacities between the anode and grid and between kathode and grid, eg.  Cga and Cgk,  of a radio valve. When the radio valve is warming up, and getting warmer and warmer, when it is delivering power, the anode dissipation is increasing, these capacities are changing, the value is getting higher. So the frequency of the oscillator is changing and getting lower. Characteristic curves and values are well known for each type  radio valve.

Now we look at these special ceramic condensers. When HF energy is applied on these condensers, by the energy of the oscillator,  the dielectric electric losses of it changes by heating up of his body, so the value of capacity getting lower.  Hescho managed to measure that amount of dielectic loss in these capacitors. so they could produce a large variety of different losses factors  in the capacitors very accurate.

 That is just what we need to compensate the frequency change, established by the warming up of the valve , so the anode, by the increasing anode dissipation. This proces is acting much faster, then the influence  of the temperature compensating material, in circomstances that the valve is switched off, so cooling down, and later switched on again. Consider, that the remainig heat in the cabinet of this valve is still reaching the temperature compensation material, while the valve has been already switced  off for a while.

So they made the curve of  these combination of condensors that way, by putting several of these condensers in the circuit, that it is compensating the changing valve curve. So frequency stability, needed in such circumstances in the airplanes, was increased well , especially in these oscillators. Note that the German equipment, especially transmitters, were not crystal controlled by lack of crystal material, which had to come from abroad and was of course not delivered almost in that war time.

But these condensers were probably only made for oscillators, not crystal controlled, of transmitters.

You can see this arrangement in the various transmitters for navy, the LO40K39, the MOPA transmitters of the FUG 10, S10K and S10L. Even, I saw it in the oscillator part of transceiver FU Sprech- f of the army. But these were probably only condensors with a temperature coefficient. In these MOPA transmitters of the FUG 10, this stabilsation method is most effective. The heat is much in the transmitter cabinets. The oscillator stage, a RL12P35, had to deliver much driving power, so getting very warm, by his big anode dissipation, for driving the power amplifier of 2 RL12P35’s, to let this amplifier provide 60 watts on CW. Below a picture of the condenserblock in a S10K transmitter. In my working FUG 10, the frequence stability is amazing, while the transmitter cabinets are pretty warm. The oscillator is of course not crystal controlled!

Kl-details-Lorenz-C5-Block-1-2Kl-details-Lorenz-C5-Block-unten-2

The condenser block of the S10K transmitter. At the right, a kind of printed circuit on the ceramic base.

I don’t think these condensers with that dielectrice loss were used in the EZ 6. Because it makes no sense. The oscillator in the EZ6 uses a low power valve, the RV12P2000. It delivers low energy to the mixer stage. So warming up of the anode is limited, so his internal capacities. But it might have been? I don’t know. But all these condensers, in parrallel, did have a different particular temperature coeficient.

After the war, this manufacturing method of this special condensor was lost and forgetten. A synthisized module was used in oscillators. The frequency stability of them, depended on a crystal controlled reference oscillator. In fact a pity, but it worked well.

De EZ 6 as a direction finder.

fug002

Here the EZ6 receiver  as my “Peil G6” installation. Just at the right above a controllunit. With the switch you can do an automatic DF ,with the amplifier V6 just below the EZ6 and you can do a DF by hand, using the big knob on it by turning it to the left (L) or to the right (R). The DF antenna will turn to the left or right .Also the speed of the motor can be tuned. Right below the rotarytransformer U11 for the powersupply. In the middle the DF instrument type AFN2. Just all above  the motordrive for turning the DF antenna. Also seen the sense antenna. The complete system is a homemade version, except for the PRE 6 motordrive.

hell-bernhard-Ysys-dev-indctr

The AFN 1 instrument. The vertical needle is pointing to the dot, when the airplane is flying just to the beacon transmitter. The horizontal needle is for the signal strenght of the beacon transmitter. Tuning at maximun signal of the receiver tuning.

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The DF antenna system. Above the sense antenna (homemade), below the PRE6 motor  drive unit.

PRE60071

Bordfunk 008

The PRE 6 motor and drive unit above and the ferriet antenne, just below the sense antenna, which is homemade one, by lack of the original one, but works very well.

This whole installation (certainly not original) is setup by my own and in fully working condition. The receiver is fed by the U11a by 24 volts DC. You can find the correct direction by rotating the little ferriet antenne  and watching the AFN 1.

Altimeter transmitter/receiver RT7-APN1.

 This altimeter is designed for measuring constantly the height of the aircraft above ground, terrain during flight. It is also suitable in conjunction with an Automatic Pilot System.

There are more principles of altitude measurements, but the APN-1

a  FM CW radar altimeter.

It is supplied with a double Range Indicator, type AYD 3. One for  till 400 ft and one for 4000 ft.  One ft is equal to 0,3048  meter.

So 400 ft is 122 m, 4000 ft is 1220 m.

Also a Limit Range switch is provided,

type SA 1, to switch for the desired altitude of the aircraft.

When no Automatic Pilot is used, the  Limit Range switch can be used in conjunction with a Limit Indicator, consisting of 3 lamps, red, white and green. All these items are at the dasboard. When not using the Automatic Pilot, a dummy connector is put in the receptable connector at the front of the transmitter/receiver J-106. When not placed and still Automatic Pilot is connected to this receptable by a cable, the change over switch on the Automatic Pilot box must be set on manual. When switched to automatic, these lamps have different functions.

In my installation that dummy is placed and the functions of the lamps are discribed just below.

At the Limit Range switch , the height of the aircraft , which is chosen to fly, or providing a flight with save height, can be chosen with the knob on it. When now the red lamp in the Limit indicator, is lightened, the aircraft is flying beneath the value on the Limit Range switch. When white, the height is about the desired value. When green, the height is above the value of the Limit range switch, so save height. See also the first picture below.

See below the block diagram of the APN-1 Altimeter.

1

firefly_apn1_system

Inter connection diagram picture.

The APN- 1 is a frequency modulated  CW Altimeter. It , just like another altimeter,  SCR 718, determines the time required for a radio wave to travel from aircraft to earth and return. A different method of time measurement is used , which depends on the observed difference in frequency between transmitted and received signal.

Principle:

If frequency of a radio transmitter is changed rapidly at a constant rate (frequency modulation), the transmitter will change frequency in the time required for a radio wave emitted by it to travel to earth and return. The higher the aircraft, the longer the time required for a round trip and the greater the difference between the transmitter frequency and that of the reflected wave when it arrives at the aircraft. This frequency change is the proportional to the altitude of the aircraft.

If the rate at which the transmitter frequency carrier varies,  is known , e.g. FM modulation, and this  signal is also modulated at a rate of 120 cycles,  is CW modulation, his frequency is varied from his center frequency of 400 Mhz , between 420 and 460 Mhz at lower altitudes of a maximum range of 4000 ft,  the elapsed time corresponding to any observed frequency difference is then established. This frequency difference (elapsed time)  is converted, in an electronic  circuit, which delivers a proportional current to drive  a meter instrument, the Altitude Indicator.

The output of the transmitter is a FM modulated constant carrier of 0,1 watts, which is radiated from a small half wave dipole, located, often,  just under the wing of the aircraft. Each wing carries one dipole antenna, one for transmitting, one for receiving.

The principle of the altitude measurement in the APN-1 will be discribed in the following presentation  below.

radio-altimeter-4-638radio-altimeter-5-638

Above the C is constant all the time, so  when T in increasing, H is increasing too.

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radio-altimeter-8-638

radio-altimeter-9-638

radio-altimeter-11-638

Above: when T is increasing, rate of change carrier frequency  is stable,  the beat frequency is increasing.

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radio-altimeter-14-638

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Above means: FM modulation of 40 Mc, CW frequency , and  and velocity factor (300.000 km/sec) is stable, then the altitude is proportional to the beat frequency.

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radio-altimeter-17-638

Above the principle block diagram of the APN-1.

Below some pictures of my APN-1 unit. Just click on the picture to get a larger one.

IMG_8357

My  Altimeter unit RT7 APN-1.

Below the transmitter/receiver. Above left the Altitude Indicator and Range Switch unit. In the mid the 3 lamps  of the Limit Indicator. Just below at that, the 2 dipole antennas.

IMG_8359

Transmitter/receiver box. Just watch the inserted dummy connector at the left, when the Automatic Pilot is not in use.

IMG_8358

Left the height indicator with 2 scales on it. With the Range switch, switching between 40 ft and 400 ft. Below the 3 lamps of the Limit Indicator.

IMG_8360

One of the small halve wave dipole antenna.

Comparison of FM and Pulsed Altimeters.

The APN 1 is a FM altimeter, a SCR 718 is a pulsed altimeter.

They are designed for different purposes. For instance for bomber aircraft, flying at great altitude and for fighter planes flying often at lower altitude. Fighter planes use often the FM units, while bomber planes use the pulsed altimeters.

The FM unit has a very small fixed error while the pulsed unit has negligible  percentage error. The FM unit is intended for better measurement  at low altitude, while the pulse unit is better at very high altitudes. Often you can see at pictures, taken in bombers, like B17 or B 29, the indicator unit of the SCR 718 , type I-152, is to be seen. See picture below.

Bombardiers_Position

Just right down to be seen the I-152 indicator at the Bombardier position in a B -29 aircraft.

avenger_observers_mate

Here to be seen in the background, the APN-1 transmitter/receiver, in a fighter plane.

In the week of the 28-th of march, 2018, I changed the instrument panel of the altimeter. I putted the antennas on a seperate base. With 2 m of coax cable to the receiver/transmitter. It all worked better, so the demo.

Below the pictures.

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The new instrument panel.

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The transmitter antenna at 400 Mc.

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The receiver antenna.

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The red lamp is lighten, that is correct, because the needle of the altimeter indicator is below the installed value of 50 ft at the limit switch.

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 The back side of the panel. Note the rare connectors at the instruments.

The demo is going very well, if you move the receiving antenna. The indicator meter and the lamps are responding very quickly. This is correct, because at the functioning of the altimeter  at ground level  is always very unstable.  At bigger altitudes it is more stable.

German Funk Horch Empfänger d.

Receiver Funk Horch Empfänger d.

In this post my new beautiful German receiver, the Funk Horch Empfänger d.

For a better picture or schematic diagram, just click at the picture. To go back, just click right of the picture or schematic.

At the  time of  world war 2, even before and also today, armies and also of course armies  in world war 2, so the German Wehrmacht, were listening at all frequencies, from long wave, medium wave, short wave till VHF. Not only enemy stations, but also the normal broadcast frequencies. All these to check them for correct transmissions and also to intercept  enemy transmissions for important information etc. Even in Germany, radio amateurs were checked out in the beginning. But very soon, they were forbidden, because they were not important to the government.

These “Funk Horch Empfängers” were very sensitive with a lot of functions to receive even small signals at any mode, like A1, A2 and A3 transmissions.

A various amount of receiver types,  a, b, c, d and f for all different frequency bands, were placed in listening centers. For these listening centers,  called the “Fu 14”, were 10 Torn, E.b’s,  3 large short wave receivers KW-E a, 2 Horch Empfanger Fu.H.E. a/c and lateron also 2 Fu.H.E.d in use.

Also special troops from the Wehrmacht used them in a portable way, the “Funk Horch Truppe”. The name  for troops, who used the type D, the F.H.E. d , was called “Fu.- Horch-Tr. d”. Code name was “Horst- D”.

.

Naamloos

Enemy radio interception with a Funk Horch Empfänger.

Some documentation:

Manufacturer: Telefunken, code name bou. Each manufacturer had its own code, for instance Lorenz was dre.

Type d.

Valves: 12 RV2P800.

Range: four ranges white, red, yellow and blue.

24,8 -31,7 Mhz, 30,45 – 39,30 Mhz, 38,82 – 49,35 Mhz, 47,90 – 51,90 Mhz.

modes: A1, A2 and A3.

headphones: type DFHa 2000 ohm.

The receiver is a super heterodyne type with a continuous variable bandwith by means of a crystal at 3000 Khz.

Also a CW filter is included at 900 Hz, “Tonsieb”.

Containing 2 RF stages, 1 mixer, 3 MF stages, 1 audion stage and 2 LF stages.

Also one stage for the CW oscillator, containing 2 crystals. Two frequencies for the oscillator can be chosen, TG 1 and TG2. Just 900 Hz down and 900 Hz above the carrier. When a unwanted signal is just down the carrier, the CW oscillator can be switched just 900 Hz above, so no problem any more to receive the correct signal.

In position TG1, a calibration signal is to be heard at several marker points of the frequency band scales, to check the frequency. This after pushing the calibration button on the front of the receiver. The antenna signal is switched off, and the calibration signal is fed to the entrance of the receivers first RF stage. Amazing fact is, that in my receiver, the frequency scales are still calibrated after 70 years! Also the sensitivity is equal over the whole band.

The MF stages at 3000 Khz, contains one crystal. The bandwidth is variabel . The calibration of this is also the same as 70 years ago!

Power supply is  housed in a separate housing or transport case,  providing two volts of a lead acid batteries and one 90 volts static dry battery. The  type leadacid battery is the 2B38 and 2 static HT anode batteries.

The receiver is complete original, inside and outside, so his case, and has it’s original color.

Front

The front of the receiver. All functions are good to be seen. For increasing the size of the pictures, just click on them.

IMG_8144

Side view of the receiver.

IMG_8141

Side view. From left to right above: Upper row 2 RF stages, nr. 1 and 2, the mixer valve and the balanced  (Gegentakt) receiver oscillator. Lower row,  from left to right below: the 3 MF valves.

IMG_8137

Other side view: above the coil holder of the HF , mixer and oscillator part.  Each wave band has its own combination of 3 blocks. The contact fingers are to be seen just at the above side of the picture.  When changing the waveband with the big knob on the front, first the contact fingers are lifted, then it rotate, and when in position, the fingers are released and make contact with the coils contacts in the holder.  It is a common construction often used in German equipment.

The 3 coil blocks, for each wave band,  in their housing, seen in the mid of the picture, are easy to replace.  Below the power supply entrance and 2 entrances for the headphones of 2000 ohm.

IMG_8142

Back side. here to be seen the Audion-, the audio- pre amplifier- and the audio- final amplifier valve.

IMG_8146

A view of the power supply entrance and the haeadphones. left the LF output transformer, which is a different one, the original is replaced because of malfunction by another German one.

IMG_8143

Upperview of the receiver. left the diodes for the AGC, eg “Mit Reglung”. In the mid the contact fingers for coils connections. Also to be seen the variable condenser for tuning the antenna. At the right the switch for measuring the anode currents for all the valves, to check them on the test meter at the left above corner on the front. All indications on the meter into the blue part of the scale. But the AGC ,”Reglung aus”,  switched off, the audio gain on maximun and switch mode,  “Tg1-Tn-Tg2” at TG 1.

Furtheron, the receiver in in good working order. All his functions are working. The only component I had to exchange was a faulty condenserblock at the right side of the receiver, number 234, powersupply,  in the schematic diagram, which was very leaky. I did restore it, by putting a new one, electrolytic one of 47 uF-500 volts Dc, into the inside. It is like new now.

Also I cleaned all the electric contacts. And lubricated the mechanical aches of switches, scale driving aches etc..

Grund Schaltbild

The principle schematic diagram. Note, that it concerns only the type d. other types, like a, b etc. differ in schematic. All valves are RV2P800.

FUHE d

A close up of the receiver between other German equipment in my collection. Left the KWEa, at the right the LO6K39.

Replica Würzberg radar transmitter, type SU 62 D.

Würzberg Riese transmitter SU 62 D of FuSE 62 D radar.

Würzberg radar is a German radar system from WW2,  to locate, mainly allied bomber convoys, on their way to targets in Germany. When located, their positions were given to the Nightfighters from a central command station, to intercept them. When they were in the neighbourhood the picked up the convoys on their own radar on board.

A lot of Würzberg radar systems were spread out over the occupied European countries, coastlines.

Their maximum range was 80 km and the working frequency was about 500 Mhz,  It even had a IFF system, called Gemse, for indicating weather the convoy or plane was enemy or freind. Its use was still in progress, when the allies made radar systems on 9,1 cm with better valves and more power, the magnetron. It took a long time, before the Germans were aware of this 9 cm radar. At the last end of the war, they developed also one, called “Berlin Gerat”. They came aware of it, after a bomber plane went down in the neighbourhood of Rotterdam, The Netherlands.

Also they could detect 9 cm radar pulses at that time, with a socalled “Korfu Empfanger”, so detecting these radar signals at 9,1 cm.

Because I am so interested in all kind of German radar in WW2, also allied ones,  I decided to publish a new post of this matter.

I have only some small parts of German radar in my collection, because it is most difficult, to collect some parts of these devices. They are very rare. But also valves for very high frequencies and magnetrons etc. are interesting.

After some visits to the museum of mr. Arthur Bauer of  The foundation of  German communication and related technologies  in Duivendrecht, The Netherlands, I had the possibility to examine his working Wurzberg radar installation. I must say, I was most impressed of it. Complete with transmitter, receiver, power supplies, units for measuring the  power and a signal  simulation unit,  called artificial target Rebock, to simulate a reflection target on the CRT.

Also the whole system is discribed in his beautiful and professional website.

Because I received some LS 180’s recently , the transmitter valve in this Wurzberg radar, I came to the idea to make a replica of the transmitter only, the type SU 62 D, belonging to the Wurzberg radar type FuSE 62 D.

Not having the idea, to let it will work once, there are so many other rare parts to be need. Just a replica, but it must be possible to let the heater glowing. Also the the length of the lecher lines are not right, but that does not matter, it does not need working.

This SU 62 D is a special one, because they could change its transmitting frequency some. The range was about 485 – 520 Mhz. This frequency change was sometimes a must,  because of possible interference with allied transmitters.

WB-Riese-Kabine-Erkl

The inside of the Wurzberg housing at the back of the telescope. Note that another transmitter receiver (the SU 62 in the picture)  is used, then the type , described in this post. The different transmitter receiver , also Eidechse SU 62 called, could operate at 2 frequencies, 560 en 540 Mhz. The visible A and B on the front indicate it. Furtheron you can see the Impuls generator IG 62, providing the gridblocking of the transmitter. The CRT on the front, a LB13/40 can indicate the controll pulses for the grid blocking signal of the transmitter.

Some below, you can see a original picture of a Würzberg Riese radar. you can see his size, comparing it with the person in front of it. The reflector dish a 6 meter.  in the focus center , some little dipoles are collecting all the reflected pulses, received by the dish. The dish could turn in the horizontal position, just as well in the vertical position.  On a cathode ray tube, a LB 13/40 you could read the distance to the target in 2 ranges, eg. 40 km or 80 km range.

CRT

Picture at CRT, a target on a distance of 18 km. Picture taken by Arthur Bauer, PA0AOB.

There are still some Würzberg’s left here in The Netherlands.  For instance one in the Liberation museum at Overloon,which is very complete, and one at the Planetron in Dwingeloo. Both are sadly suffering from weather influences, because they  are placed outside in the open air. If nothing is done, they are rusting away. That would be a pity.

Wurzberg Dwingeloo

Another, still existing Wurzberg in bad condition,  at Dwingeloo, the Netherlands at this moment, 8-10-2015, at the  former Planetron. Note, that the parabool reflector is not original, but copied after the war!

In the past, after the war, 2 Wurzberg Rieses were in use in Dwingeloo.

.ansichtkaart08-1030x694

The 2 Würzberg’s beside the Dwingeloo radio telescope in 1950. All broken down at the moment.

ansichtkaart03-1030x668

                   The Würzberg at the right (eastern side).

wurzburg

Würzberg in use after the war at Kootwijk. For radio asteronomie.

After the war , most of the Würzberg dishes  in The Netherlands, were used for observation the H2 gas radio signals at a wave lenght of 21 cm, coming from milk way star galaxies.

They made the first map of our milky way.

To get more details in observations then those made by  the Wurzberg’s, the 25 meter telescope was build in 1956. This leaded by Prof. C.A. Muller. With the Dwingeloo telescope they could make a picture, just seen from of our earth position, of our Galaxy in the Milky Way.  During some years after the new telescope was build, the left Würzberg ‘s were in use  for examinig the radiation of the sun. The Wurzberg in the  front moved in the 1980’ to the Wehr Museum in Munchen .The other also was already not there anymore. The Würzberg housing went to the Planetron, see picture.

Now back to Würzberg again:

Wurzberg foto

Wurzberg Riese, original picture.

LS 180

Transmitter valve,  type LS 180, in use in the radar transmitter of the Würzberg. The copper wires at the left are the heater connections for 5,8 -6,2 volt – 15 A.  The real voltage to be used, is written on the glass of the tube. At the right inside the anode.

Some documentation about the LS 180 transmitter valve:

Manufacturer Telefunken.

Maximum frequency 500 Mhz.

Type: UHF triode.

Output 8 KW pulsed power.

Input 12 – 16 KW pulsed power, air cooling.

Anode voltage 8,3 KV.

Grid blocking voltage 2,1 KV negative by 1,8 uS. Delivered by the Impuls Generator type IG 62 D.

Heater voltage 5,8 – 6,2 volts by 15 Ampere! Value written on the tube itselves.

I looked funny to me to make myself a copy of the transmitter part, type SU 62 D. See the result in the pictures below. It is made at true scale.

transmitter 1

The front and above seen.In the mid if the picture the LS 180.

transmitter 2

The front side. L21 is the output cupper strip, just above the anode inside the valve. Below left, the condenser  C6 and the 3 resistors in parrallel. Left a power resistor(15 A) for putting the heater value at correct voltage, written on the glass of the tube.

The condenser (0,05 uF) and the 3 resistors (16 kohm) in parrallel are in serie with the 8,3 KV anode line. They take care, that the anode only draw current, when the condenser is disloading, when the valve is not blocked by his negative grid voltage. When the grid of the transmitter valve is fully negative at 2,1 KV, the valve is blocked, the condenser is loaded again.  The anode gets no voltage the anode  is drawing a current!. The next episode, the negative voltage on the grid is disappearing, the condenser is disloading to the anode , the valve is drawing current. An episode further the whole cyclus is starting again. It is like a safety circuit for the valve, because when the negative voltage on the grid has been disappeared by malfunctioning , the valve draws only current via the 16 kohm resistor. Note that the current is DC not AC.  This will reduce his total input power. Even when it is dissipating this reduced power, other safety systems will work, so protecting the valve and probably exploding the transmitter unit.

On the right the resistor for the heater voltage, when heater voltage is applied, this wire wound resistor is a bit glowing (I got no other resistor), because of the current of 15 amper is flowing in it. But that will be not a  difficulty. Resistor will not burn away.

Just down the resistor, the supply connector for the heater voltage and the negative grid blocking voltage of 2,1 KV – 1,8 uS, coming from the puls generator type IG 62.

At the left of the casing, you see a small handel. With this handle you can tune the anode lecher and the cathode lecher at the same time to the right frequency, to be used.

The arrow warns you for the very high dangerous voltage. The red and the green stripe indicates, that the equipment was most secret.

transm 3

20150920_192928

The transmitter is working!!

But not really, only the heater is glowing.  An intensive light is there, all gets very warm too.

I used a voltage of  5, 8 volt by 15 ampere for the heater.

kathode side

The cathode lecher line and tuning, also the heater connection. In the mid of the lecher  line the tuning arm. which is tuning the length of the lecher, by shortcut a part, the quarter wave lenght for that frequency is established.

backside

The backside. The upperleft connector is used for the 8,3 KV. Also the connection cable (at the right) to the grid of the LS 180 is to bee seen.

WB-rep-Urechse-Senderprinzip

The circuit of the SU 62 D. It is just a  “simple” power pulsed oscillator. You can see the grid and cathode lecher. Capacitor C2 is for the degree of coupling, to let the system oscillate. The output device of the transmitter is only a strip, which is positioned around the LS180, so coupled to the anode,  by inductance.

WB-rep-Urechse-TX-separat HT cable 8 KV HT cable -2,1 KV a

The original transmitter SU 62 D , a picture taken by Arthur Bauer, PA0AOB, from his transmitter unit. Mr. Arthur Bauer has a complete and working  Würzberg installation in his museum.

The replica is now on display in my radio shack.

Wireless transmitter no 76.

  WIRELESS TRANSMITTER NO 76 .

The Wireless Transmitter no 76 was also  used also in the Battle of Arnhem at the Rear Link contacts to London. See discriptions in the posts Wireless set no 22 and receiver R109.

This transmitter can be only used on CW, telegrafie.  It is crystal controlled and has 6 channels. It delivers about 10 watts carrier output. There are only 2 equal valves in use, the ATS 25. Also 2 spares are inserted inside.

Inside is, as a power supply, a rotary transformer power supply for 500 volts. Input voltage is 12 volt DC.

My transmitter is in good, original and working condition. Inside and outside. There are 3 crystals inside in use for me, as a licensed radio amateur,  in the 80 meter amateur band. Lately also one for the new 60 meter amateur band.

The CW key is a no 9-a type, which is also there.

WS 76 1

Front of my Wireless transmitter no 76.

Wireless trans 76 005

Another look at the transmitter with the cables and the 100 ft wire antenna.

Wireless trans 76 003

The Wireless transmitter no 76 with the receiver R 109 a (T). The R109a was used with the Wireless transmitter no 76.

Wireless trans 76 006

My whole “Arnhem collection”. The WS no 38 mk2 and mk2*, The WS no 19 HP, The WS no 22, Wireless  transmitter no 76, R109 AT and the American portable set, BC 611.

At the left the Wireless set no 19 mk 3 Canadian, the Wireless set 101 Australian, the Wireless set no 11 Australian , the Wireless set no 62 mk2, they  were not in use at Arnhem.

It seemed, that the Wireless set no 62, manufactured in the late 1945,  was used later in the war, at the Rhine crossings?

British_airborne_troops_man_a_trench_with_a_No._76_wireless_set_at_Heldon_in_Holland,_3_February_1945._B14347

The very often published picture of the Wireless transmitter  76/receiver R109 combination in use with the Airbornes at Arnhem. Probably the phantom group for reporting to the press of the BBC in London?

lewis golden

Another picture from the Wireless transmitter  no 76 and receiver R109 published in the book of the author Lewis Golden.

Below some pictures of experiments with the Wireless transmitter no 76 and receiver  R109-a, as a radio amateur,  in the back of my garden.

The weather was beautiful, so it was a pleasure to listen to the several amateur stations, at day time on 40 meters and at evening time on 80 meters. The antenna was a dipole antenna, stations were heard in mode single side band and CW.

Some contacts with stations  were made on 80 meters in mode CW only. None on 40 meters, by lack of crystals for that frequency. But the set is suitable for that frequency. Signal reports on 80 meter were very well.

Wireless set no 38 AFV.

The Wireless Set no 38 AFV was used in conjunction with the Wireless Set no 19 in Armoured Fighting Vehicles, like tanks. For instance the British STUART tank.

At the controll units, no 16 and 17,  connected to the WS 38 with low frequency amplifier part and the WS  no 19, you could make a choice between the WS no 19 , WS no 38 or intercommunication amplifier. This  intercommunication amplifier, was used for communication between the members inside the tank. Also to increase the audio strenght of the WS no 38 receiver part.  The amplifier was needed, because of the heavy noise in the tank itselves.

WS 38 AFV

At the right  the transmitter/receiver WS no 38 AFV and at the left the intercommunication low frequency amplifier.

Operation Market Garden Arnhem and the radio equipment.

I am most interested in the history of this operation. Not only because what happenend there, but also the radio equipment used during the operation, especially used in this Market part, Arhem.

Much of these radio equipment are also in my collection.

This article is especially about the Market part of operation Market Garden, the operation at Arhem.

BATTLE OF ARHEM , september 1944.

In here I try to explain the reason of the often malfunctioning of the used  radio’s and radio nets and some history about the progress in the first days, which might give an explanation to understand this malfunctioning.

Many stories about bad working radio sets, written by writer after writer, during some 30 years after the war, were very negative, the radio’s and radio nets  should failing completely, which was often very untrue  and based on poor  examined  information.  Especially in the beginning of the operation, the radio nets were working very well. In the last part, they were not so well anymore,  because of many reasons.

 Lewis Golden, being the second officer in the Royal Corps of Signal of the 1e Airborne Divisionel Signals, who served as a signal officer at Arhem 1944, wrote in his book Echoes from Arnhem:

That such a false picture might have been painted  quite intentionally by writer after writer in the absence of informed criticism is not difficult to understand, particularly if a study is made of a quite different but closely related aspect of the operation which was entirely wrongly portrayed for some thirty years.

The operational strength of the 1e Airborne Divisional Signals was 18 officers and 330 other ranks.

My experience with, for instance the Wireless set no 22 in use at Arnhem, showed that it was a good functioning radio set, good enough to make a good contact within his range, .depending on what type of aerial was used and what time of day. When you keep in mind these parameters, it is a well working radioset.

The following books  read for getting information what happened during this battle are:

The battle of Arnhem 1958 by General-Major R.E. Urquhart, division commander of the 1e British Airborne division,

Waco CG-4A Gliders in Market Holland september 1944, by G. Thuring, a special remembrance book from the Liberty Museum 1944  at Groesbeek near Nijmegen,  The Netherlands.

Special book about an Exposition in 1991, about the radiocontacts in the Battle of Arnhem, at the Airborne Museum Hartenstein, Oosterbeek, The Netherlands, called  “CALLING  SUNRAY”,  march 1991.

Echoes from Arnhem by Lewis Golden.

Lewis Golden was present as a signal man at the divisionel headquaters at Oosterbeek in Hartenstein Hotel, during the most critical phases of fighting, and he was uniqueuely placed to observe and to understand what was going on. In this book is written,  about what really happened at Arnhem, while in many books a lot of things were told as not really true.

Setup Battle of Arnhem (Market):

First an explanation of the setup and meaning of the operation

The Battle of Arhem  was  the Market part of operation Market Garden. 

Market,  because they were all airborne units.

Market Garden means: 

                                                       Market: Airlandings units, Garden: Ground Troops.

Market Garden started in september 1944, to capture the bridges over the several rivers, canals, between Valkenswaard (Belgium) and Arnhem (Netherlands), like the rivers Meuse, Waal and Rhine, to establish a fast run to the north of The netherlands and the industrial part of Germany, the Ruhr. This, to try  making a fast ending of the war.

Short overview of the progress of the battle at Arhem in the first days.

The bridge over the river  Rhine at Arnhem should be captured by the British and the Polish.  In the first lift, the 1 st Airlanding Brigade should land on LZ -“S”, north west of Wolfheze. The 1st Parachute Brigade at DZ- “X”and LZ- “Z”, north of Heelsum. The 1st Polish Parachute Brigade should dropped at LZ  – “L”, north west of of Arnhem  and DZ – “K” south of Arnhem in the second lift.

First were the landings and after it, the dropping of parachutists. The droppingzones (DZ)/ and landingzones (LZ) at Arnhem were  S, X, Y, Z., L and K.

On the map below, is to be seen, the overview of the landing and dropping zones. From dropping zone “X”and landing zone “Z”,  3 waves of troops going to Arnhem. These 3 waves did had code names Leopard, Tiger and Lion.

routes

The 1e Air landing Brigade was in the first lift at 17 september, and had the task of protecting the landing zones and dropping zones for the second lift. In the 2nd lift, one day later, the 4th Parachute brigade and the 1 Polish Parachute Brigade should come. Because of bad weather in England, they were delayed for 5 hours.

The 1e Parachute Brigade consist of 4 brigades, the 1 st , the 2nd  and 3th battalion. Also the 1st Polish Parachute Brigade should assist as a 4th battalion, but came in the second lift. Another special group, the Reconnaissance Squadron was also a part of the 1st Parachute brigade. This unit came also in the first lift. This  Squadron had the task to go to the bridge as fast as possible with jeeps to capture it by surprise and hold it, till they should be relieved by the 1  Parachute Brigade, which went on foot to the bridge.

The 1st Parachute Brigade should march on to Arnhem in these  3 waves. The 2nd battalion should hold the the bridge for 4 days after capturing from the Reconnaissance Squadron,  while the 3th battalion was to assist by approaching  the bridge at the north.

The 1st battalion was to occupy the high grounds, north of Arnhem. They went by wave code name Leopard. They were on the left flank and passed through Wolfheze to the main road running from Ede to Arnhem. The 2 nd battalion went by wave code name Lion, passing the villages Heelsum and Heveadorp and then through the most southern part of Oosterbeek.  The 3th battalion’s route was code name Tiger, and went through the centre of the Brigades advance. They went along the Oosterbeek road to Arnhem.

But all battalions got heavy enemy resistance, and could not reach the bridge in the first days. The 3 th battalion was stopped less then halfway and had to dig in at Koude herberg. The 1st battalion was held up halfway at Johanna Hoeve.  Also the Reconnaissance Squadron did not reach the bridge. Finally the 2nd battalion under major Frost did, by the southern route.

Droppings and landings near Arnhem.

All the dropped Airbornes and their equipment, heavy weapons  in the part Market, went by Horsa- (British made), Waco- (American made) ,Hamilcar -(also British made) gliders and Dakota C 47 airplanes. The British flew by a total of  about 700 Horsa-gliders and 13 Hamilcar gliders, while in the whole operation Market, about  2000 Waco CG-4A gliders,  from the American 9th Troop Carrier Command,  were  used. The Hamilcar gliders were bigger and were  used also for  transport of Airborne jeeps and their trailers, Brenn Carriers  and other heavy weapons like the  anti-tank cannons, howitzers  etc. They could transport more weight then the others.

PicStirlingTow-1

View from a glider towards to the towing airplane, a Stirling plane. Clearly to be seen, the towing cable, which is released from the Stirling, when they got above the right landing Zone.

HORSA JEEP 1

Loading a Airborne jeep into a Horsa glider at a base in England.

HORSA JEEP TRAILER

Airborne jeep with trailer at landing Zone Z, is just leaving the landing zone. Note that the Horsa, did make a safe landing but did make a small crash and was damaged. More gliders made a crash landing at the Landing Zones, because of enemy fire and the fact, that the Landing Zones got very crowdy with these gliders at last, by lack of sufficient free places .

21st independent parachute company (14)

The  fly-in of a Horsa from the 21st Independant Parachute Brigade on Landing Zone “Z”. This Brigade was also taken care of  marking the Landing Zones (Z), by Eureka beacon transmitters for the landings and droppings, which were coming afterwards. Watch the several parachute supply containers in the fore ground.

The transport of heavy  weapons, like  the 17 pounder anti-tank cannons, jeeps, also the radio jeeps, transport carriers (bren), went by the Hamilcar- and  WACO gliders. These Hamilcar gliders could even transport little tanks if nescesairy. But these tanks were not in use at Arnhem.

Hamilcar

Here a picture of a Hamilcar glider, which got damaged at his landing. At the back at the right another Hamilcar.

The  Horsa gliders were almost only used for the para’s and their weapons, ammunition, medical supplies etc., but often too to transport a Airborne jeep and trailer with only a few men, because of the weight.

The  C47 Dakota planes,  from the 9th Troop Carrier Command,  were also used for dropping the British Airbornes in the northern Market part.

The Dakota planes also dropped the para’s of the 101st Airborne division and the 82st Airborne division in the southern part of the Market part.

.Bridge

This was the bridge at Arnhem, where it was all about. The British 1e Parachute Brigade, the 2nd battalion of Frost,  managed  at last by the southern route along the Rhine boarder, which was not fully sealed off at that moment by the Germans,  to capture the north side of the bridge and managed to hold  it with 740 men, for only 4 days.  Trying to cross over the bridge by the British was failing.

Verwoeste brug

Here the bridge, which was demolished by allied air attacks in October 1944, to prevent the Germans of taking counter attacks to the southern part, which was now in allied hands. Most of the left British, in the perimeter at Hartenstein, did already crossed over the Rhine by Operation Berlin. Picture probably taken in 1945, after Arnhem was liberated.

The Wireless set no 22.

Theirs-Is-the-Glory-13841_5

The wireless operator with the Wireless Set no 22, during the battle.

A picture scene in the post war film,Theirs is the Glory.

Until so far the setup of the operation , just like it was ment to be. But it worked out in  different , already at the start of it.

In this operation, they blaimed often the radiosets, which  were described as a bad working radio’s, because communications between the several brigades and divisions during that battle was often not well. Often they blamed the technical side of the radioset.  Also suggested in the film: A Bridge too far (1977).

But is this realy true?  There were a great deal of reasons, why the communications between the several brigades and battalions often failed.

Some reasons:

1)

Let’s consider the whole operation proceeded like the plans made for it. The communications, which should working well in their specified ranges  between the several groups, the limiting range was 3 to 5 miles, depending on which radio set was used, with what kind of antenna and what time of the day,

The contacts went by different radio nets at different frequencies. At all levels, the frequency of the radio nets should be well known by the Headquarter Division Command. . Each radio should have a correct frequency in his radio net..

The  radio nets setup , used by the Headquarter Division Command, which should be at the beginning of the 17 th of september,   in Operation Market Garden, are seen in the two diagrams below:

net diagram

Immediately after the landing of the first lift,  air landings from the 1st Parachute Brigade, the 21st Independent Parachute Company and the 1st Airlanding Brigade, on 17 september, the decision was made to be as mobile as possible, so the radio net consist only of wireless sets no 68 P. The radio net was at 16.07 hour just  like the above part in the diagram. These contacts formed the Para Report Center. The division headquarter was in the woods near landing Zone (LZ) “Z”.

There were no other types of wireless sets in use, like the Wireless set no 22.

With the second lift, at  18 september, 14.15 hour, the setup below in the picture, was planned. In this lift the 4th Parachute Brigade and the 1st Polish Parachute Brigade were flown in, however delayed for 5 hours. In this landing, the gliders brought other Wireless sets with more power output, like the Wireless set no 22.

In the setup diagram below, I made a drawing of the radio nets of my own, using several data from different sources. It is quite complete with frequency numbers/frequencies for the various brigades etc.

Although there are several publications of these radio nets, I think this setup is very correctly. But is was the planning of it in England, after a few day most changed because of heavy casualties or loss of radio material due to the unexpected heavy German resistance. Lot of links did not function anymore.

Note: also the Wireless set 46 was in use.

eigen setup radioverb

The Wireless set no 22 should be used often in the radio jeeps of the various brigade nets, to make contact with the Divisional Command Net, because of their larger range of 5 miles. The WS 68 P was used for contacts from the Brigade Command Net to the battalions, because the range between them was smaller at about a maximum range of 3 miles. Also the commanders (Urquhart) had a separate Wireless set no 22 (rover set) for contact with the Divisional Command Net in a radio jeep.

Also a communication line with the  Airborne Corps in England, and the Head Quarter of the British Airborne Corps at Groesbeek. These went by the wireless transmitter WS 76 in morse code. Wire antennas, for sky wave, were used.

And all that in  these  various radio nets with a lot of different frequencies between 2096 Khz and 6345 Khz.

So it needs a good discipline, letting these nets working well, so to use the correct frequency in those radio nets.

The communications should work well in that way.  The radioset was providing low power,  but that would be no problem, because the distance between the groups with the WS no 22 and other portable radio’s, would be small.  The range of the radio’s should be sufficient. Airborne Signal troops are trained and supposed to operate in small perimeters. The WS 22 should have a range of 5 miles, the range for the WS 18/68 up to 3 miles. Just good enough for airborne operations. The progress of all groups, in marching on to the bridge would be well, because they did not expect much resistance of the German troops there.  Of course airborne troops depend on speed in their operation for making the operation  successful, they are not heavily armed, and they depend on artillery- and air support. So a quick advance  is most important in succeeding, so the good functioning radio nets. So all would be a success, when everything would go just according the plans. When reaching the bridge, they had to capture it and hold it till the other allies from the south soon were arrived.  This was what they had in mind.

But the communications did not often work very well in practice. This because,  the whole operation did not go well as planned. Also some tactical faults and misunderstandings about the ranges of the radio’s at larger perimeters then expected, where the Airbornes had to operate in.

There were many reasons, why.

One of them, was the unexpected heavy resistance, counterattacks of the German army after a one day,  and then as a result of it,  the fall out communications because wireless operators  were killed or their radios were damaged.  These German troops were much larger then expected, also well armed, great amount of armoured vehicles and even tanks were in use, which was not all  known by the allies, or were not taken seriously?  Information about these came also from the local resistance. Even air pictures were taken. But still not taken seriously?

So a quick advance of most of the airborne troops, which was very important, was delayed  They only had to hold the bridge for a couple of days, when the rest of the allies came soon at the south part of the bridge. The delay of marching on was too large with a lot of casualities and losses of material.  The effect of speed was gone! And then an Airborne Company becomes in a great dangerous situation, when they have to fight constantly with their light weapons, against the German troops with their armoured cars and even tanks.

2)

Other reasons, why these radio nets, and so the radio’s,  failed often: 

a)

Because of the heavy unexpected resistance of the recovering German troops , already after one day,  many radio jeeps, with the WS 22 at the back of the jeep, also the portable radiosets like WS 18, WS 68,  were destroyed. Also a lot of well trained radio operators were killed. There were none or very small replacement for them. So several important  links between the several nets did not function anymore.

Mind that the wireless operator was the only one who was trained and can netting the wireless sets to the correct frequency in a radio net! Eeach radio net had there own type of radio’s, wireless operators were trained on these radio’s. The could often not work with other different radio’s of other nets. For instance the radio of the Artillery, the WS 19 HP. This group had their own wireless operators, which were trained on this set, etc..

Also  the  the Division Command Net, had no contact  with  the  1e Para Brigade headquarter . So the commander (Urquhart ), who was in this net with a WS 22.

b)

Also the planning and setting up of the radio nets in England were, by lack of time, not precise. The frequencies of the nets were for a great deal, not tested . Training exercises in these communications in the UK showed that these were working pretty well, as long the radio sets, like WS 22 and WS 18/68,  were used on the limiting ranges of 3 miles for WS 68 P and 5 miles for WS 22. When ranges became larger, at Arnhem ranges became larger, and especially in surrounding with buildings, trees, they did not  function anymore, the  communications failed. These failures showed up also in the landing earia in Italy, where ranges became larger. Airborne troops are trained to operate with these radio’s with  these limiting ranges of 3 to 5 miles, not in expanding perimeters. That ranges at Arnhem became larger, was known by the Signal divisions, but were ignored by the Staff?  The distance from the Division headquarter  to the bridge was 8 miles and to the Corps Head Quarter at Nijmegen was 15 miles!

It was known, it was explained, it was recognised, it was accepted, such was the urge to get on with the operation.

Radio’s with more power could be a solution. in increasing ranges. But there were no replacements for the radio’s so close before the operation, because radio’s with more power did have a bigger size and weight. Size and weight were limited in this airborne operation, because of the limited available airplanes and gliders for this operation. And do not forget, that the wireless operators had a training for those lightweight and less power radio sets, time was not there to train them eventually for these other radio’s.

 They finally hoped and expected (!), that resistance was very less, and that when the bridge was captured fast, most of the troops were also already in close perimeter to the bridge, so the ranges were sufficient for the communications.

But at Arnhem, it packed out all different.

c)

The distances between the several units became also large because of unexpected circomstances. The range of the radio’s was ment for a maximum range, as described above. The increasing ranges became often not sufficient  for making contacts with the troop ahead. Also the surroundings of the terrain effected the range of the radio’s.

f)

For the Rear Link nets, communication with the 30 st Corps at Groesbeek and headquarter at London, e.g. WS 76 transmitter,  the crystals were often defected already or after a few days destroyed with the transmitters by heavy fire.

The problem with these crystals was, that frequencies of the radio nets were planned frequencies for day and night time, just for all the 24 hour. Crystals for daytime were the higher frequency ones. During night time contacts the lower frequency crystals should be used. And that for frequencies according the plans.

Why : to get the most increased range, e.g.  London, according the frequency range of the equipment, e.g. WS 76, you have to transmit at higher frequencies (above aproximately 5 Mhz) at daytime. Sky wave range is big. So sufficient range for base stations in the UK.

At night, you have to use lower frequencies (aproximately from 1,5 Mhz till 4,5 Mhz) for maximum range by sky wave, to reach London.

But the crystals went often defected. Resupply of these crystals, for instance daytime crystals,  became mostly in enemy aria. So they had to use night time crystal at day time, what did not function. Range was poor, not sky wave but ground wave.

 The problem was, that the WS 76 transmitter could function only at crystal control, so the crystals had to be used, so fixed frequencies.

So in this new situations, contacts with London were very bad after a few days.

g)

Often the various brigades etc. were not always in the same radio net, they used to be in, each radio net had their own frequencies.

An example was the Division Command Net with the the Reconnaissance Squadron Net, which was never meant to be in the same radio net, although they thought, they were. They had their own radio net.

The plan was, that the 1e Parachute Brigade should defend the captured bridge The 1st Parachute Brigade landed about  8 miles away from the bridge and had to walk on foot to the bridge. The Reconnaissance  Squadron, however, landed first on 17 September,  under commander Major Gough. They should take the bridge so very fast, that the element of  surprise was not lost. This by using 31 heavy armoured jeeps. They should soon be  followed by the the battalions of the 1st Parachute Brigade on foot. When arrived, they should take over for the captured bridge. Then waiting for the 30 st Corps.

This Reconnaissance Squadron had a different special task and was under command of the 1st Parachute Brigade, it became a “coupe de main” role.  Speed was necessairy. When the  Reconnaissance Squadron should reach the bridge, they should capture and  hold it, till it  should be released by the 1e Parachute Brigade under Brigadier Lathbury. So they soon started after their landing on the Landing Zones at 17 September, for the bridge.

The role of the Reconnaissance Squadron was to be of the utmost importance to the success of the whole operation, capturing the bridge, this by the effect of surprise. They soon started the way to the bridge, while the 1st Parachute Brigade started later going to the bridge. They took the WS no 68 with them.

h)

Rumors and others.

The commander, General Urquhart. who  stayed behind at his headquarter at Landing zone Z, he was in the Division Command net, could not establish radio contact  with the 1e Parachute Brigade in this net, so no information about the progress of the operation. The Brigade started soon after the landing for the bridge. The should use a more powerful WS 22 for contact with the Division Command Net. But without allowing sufficient time to open the WS 22, they headed for the Bridge with only the WS 68 P, which had a more limiting range, then the WS no 22. When they got in the Arnhem surroudings, the range of 3 miles of the WS 68 P was to poor to make good contact with the Divisional Command Net at the LZ, e.g. General Urguhart.  Also the buildings and trees absorbed the signals, so influenced the range. With the help of the WS 22, it could be functioned.

Besides not using the WS 22,  this WS no 22 was later earmarked for another task. The 1st Parachute Brigade had expected to receive four WS 22 sets, namely one for use in the Divisionel Command net, one for the Brigade Commander and two spares. In fact the glider containing one of the sets not arriving and one of the others was destroyed by enemy fire during the fly-in, so only two sets arrived intact. The brigade commander took one of them for his rover set. and the signals officer intended to put the other to the Brigade Command Net to the 1e, 2e and 3e battalions at the first halt, because he had then a more powerful radio set then the WS 68 P.

Also the following rumor reached Urquhart. The rumor, which seemed after all not reality. The safe arrival of the squadron gliders of the Reconnaissance Squadron, carrying a total of 31 jeeps, which were essential for the “coupe de main” force to the bridge, were damaged by crashes of most of the gliders. In reality only 3 jeeps were damaged at  the landing, so 28 were there. But this was not told to him.  So he thought, that the progress of the Reconnaissance Squadron had scattered. So the effect of reaching the bridge fast, should has gone.

So he wanted to  make immediately an alternative plan with Gough and the plan that Lathbury should be told that his 2nd battalion, under John Frost, was now going hell-bent for the bridge alone.  He decided to go, with a chauffeur and radioman in a jeep with a WS no 22 radio set,  to the Arnhem aria to do so.

On his route his wireless operator was trying constantly to make radio contact with the Reconnaissance Squadron. But unfortuniatly the the WS no 22 in the Division Command Net was not in the radio net of Gough. They had a radio net of their own. These nets had different frequencies. That was a an unexpected mistake, which was not planned and  got a big influence on the progress of the battle. Because he could not make of course,  radio contact, he left the jeep at one moment and went by foot, to look after Gough. He did not manage to reach Gough because of heavy German resistance. When he came back, he saw that his his jeep was hit by mortar fire, the radio set, a WS no 22 at the Divisional Command net, at the back of his jeep was damaged and did not function properly. The wireless operator was badly wounded and was being removed by stretcher-bearers. So ended an attempt of establish radio contact over a radio net which was never meant to exist. If signals had failed it was through a missue of signals.

But general Urquhart did at least found brigadier Lathbury, commander of the 1st Parachute Brigade, who was with the 3th battalion at that moment. With his radio set, he contacted the Division Headquarters Net, which informed him of the progress of the 2e Battalion to the bridge. Reception was spacmodic and difficult. At about 21.30 at 17 september, just before the radio failed,  the brigadier told him, that Frost’s 2nd battalion did reach the bridge.

i)

 The supplies, which were dropped, did not reach always the troops. So, spares were not there, for instance  weapons and other like the replacement of crystals for the radio transmitters. Also replacing damaged radio material was scattered. Also supplies, although they were dropped on the right DZ’s, did not reach them, because these original and planned  dropping zones were fallen into enemy hands already, which was not known at that moment.

Only  13 % of the supplies were dropped correctly.

j)

 A lot of radio jeeps were damaged by the heavy German counter attacks. So the generator sets, also at the back of the radio jeep, for charging the radio batteries, often were damaged and not functioning anymore. So the radio sets did not have anymore battery power after some time, if still the radio sets were in working condition at that moment. In that case , if possible, they used  the vehicle batteries of damaged jeeps, but when, some time later,  these were discharged, and it was over and out.

radio jeep

Airborne radio jeep with WS 22. In the middle at the back of the jeep, the generator. Also some radio batteries and antenna wires.

container WS22

Wireless set no 22, dropped  in a special container. This container was attached to a parachute, then dropped out of the airplane to the dropping zones (DZ).

k)

Also the terrain with many hills and woods in  the neighborhood of Arnhem and Oosterbeek,  were effecting a secure communication, especially for increased distances. It was also recognized in the training excerscises with the Airborne troops in the UK, before the starting of the battle. So were the portable radio’s, with even less power,  like WS no 68 P and R with only 0,25 watts. The range of the WS no 68 was 3 miles with rod aerials on speech. But in open terrain!  Especially the WS no 68  failed in good communication in these surroundings, while another radio set in use, the WS no 18 was some better. This due to the frequency of the the WS 18, which was higher then these of the WS 68 and because the rod earial was mounted on a base on top of the case of the transmitter, while the aerial of the WS 68 was at the leftside of the case.

Power of the WS 22 was also low, only 1 Watts. The range was 5 miles on rod aerial, on speech. Much radiation of the signal was also absorbed by the surrounding, The antenna was mostly a whip /rod aerial at the back of the radio jeep.

But also wire antennas were in use at a stationary post. These were suitable for sky wave contacts for bigger ranges to Nijmegen.

The rod antenna was a vertical one.  The radiation was easy absorbed by hills, trees, sandy surface and buildings etc.   These contacts were so called ground wave contacts, only suitable for short distance. The maximum distance was expected about 5 miles for the WS no 22,  now because of these surroundings just 2 – 3 miles, in fact most distances seemed to be 10 to 15 miles from the Division Command Net at the LZ to the troops, who reached Arnhem.

l)

Only the Rear link communication with the headquarter in London and the 30st Corps in Groesbeek sometimes worked well at the beginning, because of their horizontal wire  antennas (inverted L-antennas) and most radio’s and their crystals were still functioning.  The radio sets were the receiver R109 and the transmitter WS 76 on CW only. But after a few days, most of these radio’s were destroyed by enemy fire.

The Wireless set no 76 and receiver R 109 were also in use in a different radio net by the “Public Relation” group for reporting to the BBC in London. This contact was mostly well working. The contacts were made by the Royal Corps of Signals, the Phantom regiment.

The Phantom regiment used NVIS. which stands for Near Vertical Incidence Skywave methods.

Explanation NVIS contacts:

By NVIS the radiated signal from the transmitter was nearly almost going totally vertical upwards and was then refected by the ionosfeer above towards to earth again. The advantage was, that the dead zone was very less, so you got a much better contact with stations at a distance of about 100 till 150 km. Just about a little from  the landing zones to the 30th Corps at Groesbeek, south of Nijmegen. Using a dipole antenna, the dead zone was mostly larger, depending of the height of the antenna, time of day, season and the used frequency. If the dipole had a height of at least a quaerter wave, the most radiation establish a larger dead zone. At a frequency of for instance 14 Mc, it is very large and has a distance of at least hundreds of km’s. A dead zone means: the distance between the startingpoint(antenna) and the point where the relected signal comes back for the first time to earth.

Also these NVIS contacts with the Allies at Nijmegen did not work always, especially at the beginning, for asking artillery support. To get information about the situations, they decided to use  the WS no76 and receiver R109 . Information for the allies, for instance artillery support in Nijmegen  from the perimeter at Hartenstein,  first went to London and from Londen to Nijmegen etc. These contacts worked well. But only at special day times! Other contacts with the WS 22, did not work well in practice directly to Nijmegen. This because the distance between them was too big for ground wave contact and too little for skywave contact. The dead zone between them was critical. Because of skywave the signal jumped almost over the target, a groundwave goes straight on to it and but has a small range. That was the problem for making good contact. It was critical because of the dead zone, and because of the few power of the used Wireless set no 22. Lateron also the Wireless set no 19 HP of the Artillery, was u

sed, because of the increased power, it was less critical and worked well.

A critical note about the range of the Wireless set no 68. The range should be 3 miles. But this was in ideal circunstances.  In open terrain, no woody terrain for example.

The set was a manpack, at the back of the soldier. It used a vertical aerial. In this position, the maximum radiated energie depends on a good capacity between the set and earth. That is a electrical law. The capacity to earth in this case, was of course no counterpoise or else, but the body of the soldier. Suppose, you match the vertical ( a provision on the set was there, to do so) in a fixed position of the soldier to maximum aerial current on the meter of the set. The range might be 3 miles, depending how large the capacity was at that moment. But, because the soldier is on the move, sometimes laying on the ground, because of enemy fire, a big mismatch could occur, because the capacity to earth is changing very much. In practice, in war circomstances, you don’t rematch your earial all the time. You don’t have the time often. So the range, in practice, decreased often. So staying close together, communications should work well.

That is why, the Reconnaissance Squadron took a big mistake  by using the WS 68 in a rush, instead of unpacking and installing the Wireless set no 22 on the to be used jeeps. But, as mentioned before, there was a lack of WS 22 at that moment, maybe the officers made that wrong decision, of using the left WS 22 (2) for themselves, instead giving them to the Reconnaissance Squadron Or there was no other way, doing so?

The steel body of the jeep was a much better and more stable capacity to earth. And, of course, its power output was more. So communication with the Divisional Command Net, at the Landing Zone, and other WS 68 man packs should function much better. And distances became larger, because of reasons mentioned before.

So in fact, the proper function of the WS 68 scattered, not of technical reasons, but because of the reasons above. Maybe, if these signallers were radio amateurs in their civilian lives, they should understand these problem?

So it was not the technical condition or design of the Wireless sets, which established the often failing of the radio nets, but it was a complex amount of  many, many other reasons, described in the text before, and constantly changing situations because of heavy, unexpected enemy resistance. I tried to give an explanation in this article, why.

While, as said before, very negative, unexamened publications in several articles after the war, which was not really true, also explained by the auteur Lewis Golden in his book.

Below the discription of other  special important radioinstallations, for increasing the succes of the battle,  used during the battle.

VEEPS.

At 17 September,together with the 1e Airborne Division, 2  American Air Support teams with  2 “Veeps” were dropped with them, by 4 WACO gliders on the landings Zones Z near Wolfheze. The landingzone X was the first plan, later changed to Z.

A Veep means a radio installation at the back of a jeep, consisting of a SCR 193, transmitter BC 191, a receiver BC 312 for HF , and a VHF SCR 542 transmitter . These teams got their training, just one day before the operation started.

These VEEPS were used  for Close Airsupport to the British Airborne Corps and in making contacts with the 82e (US)- and 101e (US) Airborne Division at Groesbeek  But unfortunately the frequency  of the BC 191 and BC 312 , could not be tuned at the frequency  of 2968 Khz of the to be used radio net.  Also with the VHF SCR 542, they could not make any contact with airplanes, flying over. Because of different radio crystal channels?

So effective airsupport  during the operation was missing.  Only the last day of  the battle , by improved  methods, an air support came through, this by the Phantom brigade.

Later on these Veeps were destroyed by the heavy enemy  fire in the neighbour hood of Hartenstein,  Oosterbeek. The problem was, that these radio’s could not dug in, like other radio’s, like the WS 22. Power consumption was that much, that even the motor of the jeep had to run, delivering the power consumption.

IMG_0001

Some pictures of a VEEP, displayed at a exposition at Hartenstein Airborne museum in 1991.

Eureka-Rebecca.

Also, to lead the  airplanes, towing their gliders, to the right position of the landing zones, an Eureka/Rebecca installation was used. The  Eureka mark 2 beacon used at Arnhem was the type TR 3174 with 5 channels at around 220 Mhz.

The Eureka was dropped together with the  21e Independent Para Brigade. This Brigade had the task of placing the Eureka transmitter on the Landing Zones. A kind of Pathfinder group.

These Eureka Rebecca’s worked well at the first day. After the landings, all were destroyed. So not any one got into enemy hands.

The Eureka transmitter  receiver was switched on at the Landing Zone, and was in  that  way,  marking the position of it by its radio signal.

At some  airplanes  , a Rebecca transponder with indicator unit with optical screen (CRT) was placed. With the figure on this screen, the airplane could navigate  to the right position of the landing zones. With some types speaking to each other was possible.

Rebecca

Eureka Mark 2 beacon, at display in Hartenstein Airborne Museum in Oosterbeek.

The AMES TYPE 6 Light Warning Set.

In the planning of Market garden, they knew, that the Airborne troops were a easy target for German enemy fighter planes.

There fore, plans were made, to make a long air landing strip of 1000 meters near Nijmegen for Beaufighter planes and eventually night fighters. To lead these planes, a RAF Ground Controlled Intercetion (GCI) radar station was needed.

Already in 1941, the British TRE started to develope mobile radar installation with a range of 50 miles. In 1942, socalled Light Warning Sets (LWU) were made, which fitted in 3-tonner or CWT freight car.

With the help of the Air Ministry, also LWU and GCI were developed for airborne use. So 2 LWU’s and a GCI set with personel were placed in the 38 Group RAF and under command of the headquarter of the 1e Airborne Corps.

At 17 december, these installations should be dropped by gliders near Nijmegen. However, later that day, the location was changed to the landing Zone “X”, near Wolfheze at Arnhem.

At day “3” of operation Market garden, the 878 st (US) Aviation Engineering Battalion would make a landing with gliders near Wolfheze, to establish this landing strip. The 2 LWU’s should be delivered also with these gliders. For each LWU, 2 gilders were needed.

One LWU (no 6080) with 9 men personnel, had to be carried by 2 Horsa’s. From one Horsa (chalk Number 5000), the towing plane, a Stirling, was hit and crashed near Opheusden. The glider landed near Hemmen in the Betuwe. Because the right landing zone was missed, the installation part, which formed a complete installation with the other part in another glider, could not be used and therefore it was destroyed.

The second Horsa, Chalk Number 5002, with the second part of the first one (LWU 6080), landed at Landing Zone “X”. but was soon hit by enemy fire and was very damaged.

The second LWU, no 6341, with 14 men personnel, also got lost. One Horsa, with the first part, was hit during the landing and crashed near Dodewaard. The second Horsa, with the second part, landed correctly at the landing Zone. But, because of the loss of the first part, they had to destroy it too.

So the use of Light Warning Sets near Arnhem ended into a disaster.

LWU 1

Above a picture of a Light Warning Set, AMES Type 6 ( AMES, type 6,  means Air Ministry Experimental Station type 6), displayed at the Hartenstein Airborne Museum at Oosterbeek, many years ago. It was a loaner and almost complete. Unfortuniatly, it is not there anymore, just like other important radio’s like WS 22, WS 76, R109, since the museum was overhauled some years ago.

PPI

The PPI of the radar part of the LWU. AT his display, cathode ray tube, positions of airplanes in the neighbour hood could be displayed.

So far the the story about the radio communications in this Arnhem edition.

One of the several radio’s, used at Arhem, was the Wireless set no 22. Others are discribed in the other posts of this website.

Wireless set no 22.

In the picture below, my  Wireless Set no 22 in working condition.

WS 22 view

WS 22 view, left the power supply and right the transmitter – receiver.

  Wireless Set no 22. Providing only 1 Watt output power on phone and CW.

As a licensed radioamateur I used the WS 22 on phone with much succes in the 80 meters amateur band, all through the whole Netherlands. Even on the new 60 meter band, (5350-5450 Kc) also, though only with 0,5 watts output. Of course with the help of a large dipole antenna. It is amazing, what such  less power will do, thanks to the good modulation.

Me in front of the WS 22

Here I am working with my Wireless set no 22 with an other radio amateur in the 80 meter band, using my 20 meter dipole antenna.

Just a bit in style with the Airbornes  🙂

——–

Receiver R 109 T – tropicalised.

Receiver R 109, type  T.

Receiver R 109 T. This British receiver was used in conjunction with the Wireless Set no 76 transmitter. This transmitter no 76 was crystal controlled and only suitable for CW. The T stands for tropicalised, which means they are suitable for operating in the tropic theature.

At the battle of Arnhem, both, the R109 and the Wireless transmitter 76, were used for the REAR LINK  radio nets with the headquarters in England and the 30st Corps at Groesbeek . Antennas were longwires. The communications worked in the beginning often very well. Later not,  because most of may reasons:

1) the crystals got defected and had to be replaced.

2) Also many were destroyed, together with the transmitter by heavy enemy fire. Replacement of the crystals , which were dropped,  mostly  became behind enemy lines. The functioning of these radio’s, because of sky wave contact, are described in the post of  the Wireless Set no 22.

3) many special trained wireless operators were killed, because of the heavy German resistance.

Note, that the combination of Wireless transmitter no 76/receiver R109 was also in use by The Public Relation Group in a different radio net, only CW mode. This by the Royal Corps of Signals, the Phantom group. They reported the progress of the battle to the BBC in London.

At the last days,  because this radionet was still functioning well and other Rear Links with WS 76 and R109 not well anymore, most radio’s were destroyed,  they decided to use the net with their radio’s from this Public Relations group, by lack of other transmitter no 76,  for communication with the headquarters.

PicRadioJeep

British_airborne_troops_man_a_trench_with_a_No._76_wireless_set_at_Heldon_in_Holland,_3_February_1945._B14347

The two  pictures above:

At the first picture, is to be seen the wireless operator at the left,  with his headphones still on his head, giving fire support to the airborne soldier right. This in the southern part of the perimeter around  Hotel Hartenstein.

At the second picture, the transmitter Wireless transmitter 76  at the right with the receiver R109 at the left,  also in the garden of the perimeter around Hotel hartenstein, Oosterbeek. Probably this radio set was in use at that moment, by The Public Relation radio net.

The pictures below, shows my  receiver, it is in excellent, original condition.

But tropicalised versions, mostly are in well estate.

 Inside mid R109 T

Left the whole receiver part. In the mid the service chassis with spare valves and at the right the vibrator power supply working on 6 volts DC.

left inside inner R109T

Receiver part with spare vibrator for the power supply.

underside chassis R109T

Beneath the chassis. In the mid the service chassis.

Case R109 inside

Inside the case, with the schematic diagram for service.

Finally some time ago, at last the missing grill for the front came. A nice view now, the receiver is now complete at last.

See picture below.

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Wireless set no 38 mk 2 * and 2.

Wireless set no 38 mark 2* and mk2.

WS 38 mk2 ster

This is the Wireless Set no 38 mk2*. It is a modificaton of the mk-2 version. A lampholder and pushbutton, to indicate output power, at the mk 2 version,  are missing and replaced by a metal cover plate. Also to be seen in front the control box for the throat microphone and headphones.

This radio , the mk2 set,  was  also used in the battle of Arnhem as a portable radio in some of the battalions.

First picture below, the WS no 38 is to be seen.

Voor hartenstein na de Slag AJ50 (2)

Arnhem garden

The 1st picture above, a destroyed Airborne jeep at Oosterbeek, Utrechtse weg. Just watch at the left under of the picture, the Wireless set no 38 on the ground! Just enlarge the picture for a better view, by clicking just at the picture. The picture below, is the same situation nowadays. The houses at the back are still there.

This picture was taken at that time at the north side in the garden in front of Hartenstein Hotel, being now the Airborne Museum. All still can be recognized nowadays. The garden, with the houses at the background, are still there, with now at the left, a memorial statue in it. In front of that garden the “Utrechtse weg”  road. Coming by car from Arnhem along the Utrechtse weg , this situation is clearly to be seen at the right in front of the museum. You can’t miss it.

Wireless set no 38 mk2

Wireless set no 38 mk2

WS 38 mk2\

This is the Wireless set no 38 mk2. It is a modification  of the WS 38 mk1. Watch the lampholder and black push button. By pushing the button, the lamp will be lighten up during transmitt.  So an indication of output power.

The British Wireless set no 19 High Power (HP),

The British Wireless set no 19 HP

 WS 19 HP britisch

This is the Wireless set no 19 HP in my collection.

This radio was used also in The battle of Arnhem,  by The Royal Artillery Brigade radio net, for asking artillery support. They landed  near Arnhem at 17 september 1944.

The task of the Royal Artillery was demanding to ask fire support to the paratroopers. They also  were  with the paratroopers in the first lines, marching on to the bridge, as scout troopers to give information about the german situations ahead. This information came to the Command Division Net 1,  by radio’s, like WS 68 R. The 1e- and the 4e Paracute Brigade did have  7 teams under command. By lack of sufficient airplanes, only a part Of the Royal Artillery was dropped at the landingzones. Because of the weight of  the Wireless set no 19 HP transported by the gliders, only 2 WS 19 HP sets were permitted to be dropped.

Because of the limitted amount of airplaines, the landings and droppings of material and troops, were over 3 lifts. Because there were so many troops and material.

At the 1st lift at 17 september , there would be only radio contact by the WS 68 portable transceiver. This because, the second lift with the more powerful WS 22 radiosets in the  heavy armoured Jeeps, were dropped at 18 september. These was the socalled Para Report Centre. At 16.07 a contact was between the HQ (TAC) and The 1e Para Brigade, the 1 Air landing Brigade and the 21e Para Brigade with their WS 68 radio sets.

Frequency in use was 2096 Khz., the range with the WS 68 should belimited to 3 miles.

At  17 september , the 1e Airlanding Brigade  together with the Division Command net 1,  with the Commander General Major URQUHART in this net, were positioned in the woods  east of landingzone “Z”. They had also in use a Wireless set no 22, the range should increase to 5 miles by using this WS 22.

At 24.00, the net results with  the Division Command Net  were not so well:

Para Brigade no contact,

1e Airlanding Brigade  from 23.00 no contact,

so even the 21e Independent Para Company from 23.00.

At 17 september The Division Command net 2 with radio telegraphy (Wireless transmitter 76 and R109 ) with England was broken at 21.45. Just some moments,  the contact was there.

At  18 september, 08.00, the Division Command moved to near Arhem. A new headquarter was housed now in Huize Hillock at the Utrechtse weg. At 16.30, they went to Hotel Hartenstein at Oosterbeek.

Also the Royal Artillery  went at 18 septembert to Hartenstein. They tried to get contact in the afternoon with a Wireless set no 22, with the  Forward Observation Officers (FOO) at the south of the river Rhine .  They used  a 10 meter longwire antenna. But this failed. They did a  second trial, now with   the WS 19 HP from the Royal Artillery, because of its bigger power output . It failed again. By removing it to the second floor, they finally could make, for artillery support, contact with the artillery of the 30-st Corps at Groesbeek. This because of the constantly heavy shell and mortar fire.  But soon they had to remove the radio to the cellar basement , because of this heavy fire. It was functioning the first days very well, all though later on a relay station was used on the southern border of the Rhine river.  Other wireless sets, by lack of sufficient output power, had sometimes contact with the 30e Corps. But the WS 19 HP contact was very good all these last days.

The headquarter, with a small amount of men at  Hotel Hartenstein, in a well defended perimeter, had to stay there, because of increasing German attacks. They wanted to reach the brige, but because of the heavy German resistance, this failed. They had to stay there till the 25/26e september.  

Position got worse by the hour. The perimeter got very difficult to defend. Many men were killed and wounded. So the loss of material and radio’s which were destroyed,  they AT LAST decided to leave this perimeter. This was called Operation Berlin. A small group of men escaped by small boats across the river, with the help of the Polish division at the southern side of the river. A few men  stayed behind with the wounded and were keeping the Germans busy with all kind of radio signals etc. Also some other survivors , who could not be transported across the Rhine, were hidden by the local resistance. At 21e of oktober, another small group escaped.  At the end of october another trial:  but this trial failed. All remaining working radio’s and other communication materials were destroyed then. Some survivors, wounded, were left behind and were later transported to prisoner camps in Germany.

But the Wireless set no 19 worked very well at Arnhem. This because his bigger output power, so the larger range.