Transmitter/receiver TR 9-F


A short historie of the TR 9 and his successors.

The TR 9 is the pre war wellknown sender receiver.  Although the type 9 F is was used in the bigger aircrafts like the early Lancaster bomber etc. for communication between the airfieldtower and the aircraft or in close distance to others. The TR9 D is slightly different. It was fully remote controlled bij bowden cables. The TR 9 (D) were used in the Spitfire and Hurricane.

The TR9 F and D were especially used in the beginning of the war, in the battle of Brittain. Although his succesor, the TR 1133 was already there. The TR9 was in use in the Battle of Brittain instead, but not his succesor TR 1133, which supposed to be. The production of the TR 1133 was to small to deliver enough sets for the RAF at that time. They needed more transceivers for their increasing amount of fighters.

The TR 1133 was a VHF set with a frequency cover of 110 – 120 MHZ, and an output of about 5 watts, instead of that the TR 9 providing only 0,5 watts. The increasement of output was a big advantage.

The TR 1133 was already in use in the Spitfire and Hurricane at the withdrawal of the British army at Dunkirk in the beginning of the war. During the withdrawal the sets were all disadmantled out of the left behind airplanes, to avoid that they became in enemy hands.

But the TR9 stayed in service till after the battle of Brittain. Before the TR9 was superseeded after the battle by the TR 1133, the TR 1196 was introduced. The TR 1196 has a frequency range of 4,3 – 6,9 MHZ. The advantage of the receiver of the TR 1196, was that the receiver was crystalcontrolled.

After the TR 1196, came finally at the end of the war the TR 1133, a VHF set. But the TR 1133 was not so succesful and was soon replaced by the TR 1143.

Because there was a big cooperation between Brittain and the USA, they gave the design of it to the Americans. The designed the SCR 522 , with receiver the BC 24, and transmitter BC 625. It was almost the same design like the TR 1143. It was almost equal, even the typical british jones plug were used.

The SCR 522 was also used by the RAF in their fighterplanes.

Some technical details:

In the first early Lancasters, the TR9 F was positioned under the navigator table. And was used by the pilot for communication between airfield tower or between the squadron airplanes.

In the TR9D, the receiver type R1120 and the transmitter type T1119 is used, while in the TR9F the receiver type R 1139 and transmitter type T 1138. The receivers have the same schematic, but the transmitter has a different schematic. It is the internal connection I/C which is in the T 1138 is not connected, while in the T 1119 is. The I/C connector is an extra connection to input of the 3-stage audio amplifier in the receiver. In the T 1119 transmitter the I/C is connected to the external mic . So in the TR 9 D the 3-stage audioamplifier can be used also as an intercommunication amplifier.

In the T 1138 transmitter the external mic is connected to the micc transformer V3. This external mic connection can be connected externally to an A 1134 intercom amplifier acting as a preamplifier for an dynamic microphone. This for modulating the transmitter in mode A3 (anode/screen modulation).

My TR8 F It is working now in the 40 meter band with a crystal on 7078 Khz. It gives 2 mA on his antenna current meter into a Aerial Artificial no 1 A. ( See also the post Aerial Artificial no 1A). That supposed to be about 0,5 watts.

The receiver is a TRF receiver. It consists of two HF amplifiers, VRSG 18. Backfeed could be arranged in the second HF amplifier. This is arranged by a variabel condensor, which can be tuned on the front of theTR9. Called reaction.

A VR 21 is used as a triode detector. Followed by a three stage audioamplifier with also VR 21 triodes.

The transmitter is a three stage type and crystal controled.

One VT 20 as a crystal oscillator , A second one, VRSG 18 as a power amplifier. Also a a VRSG 18 as a modulation amplifier for A3 mode.

The transmitter has 2 channels. One is the normal channel N for communication and the S channel is the special frequency channel, which could be used for  PIPSQUEAK purposes. This system is discribed in the post PIPSQUEAK.

The front of the transmitter. 

Kerst 2008 065

Inside the transmitter.

Kerst 2008 064

The power amplifier tube in  the transmitter.

Kerst 2008 063

The power amplifier anode coil in  the transmitter.

The front of the TR9 F. Left the transmitterpart, right the receiverpart.

The intercom amplifier, type A 1368 connected, by lack of the original used amplifier type A 1134, to a homemade plugboard. My A 1134 is used for the T 1154 transmitter.

The front of the A 1368. Note the missing switch at the left , which is there at the A 1134. The amplifiers are the same, with same radio valves, same powersupply voltages 2 volt DC and 120 volt DC. Only the connector on the plugboard are smaller ones. So my plugboard can not be used with the A 1134.

Board with headphones connection, psu connection and the volume gain knob. The volume regulates the Second grid of the HF amplifier of the receiver.

This is a picture of a TR 9 in the Science museum. Probably the TR 9 D for fighterplanes, Spitfire, Hurricane. Watch the remotecontrole with bowden cables and in the mid the volume gain control. The remote control is extremely rare and hard to get.

The above pictures the setup of the TR9D in larger airplanes, like the Lancaster bombrer.

Posted in RAF TR - TA radio's.