This is my new German receiver. The E 52a made by Telefunken. It is produced at the end of the WW2, say 1943.
In fact it was a rare receiver. Only 2500 receivers were produced at the last years of WW2. Maybe only 500 were left after 1945. My receiver is an E52a-1, Luftwaffe Nummer :LN 21000-4. Only 92 receivers were probably left of this type after 1945. So pretty rare.
Some history and data:
The E52 was also in use at the German Kriegsmarine. In U-boats of the types VII C, IX C and XXI. The picture below the U-boat U 3503. This U-boat was a type XXI. And was build by F Schichau GmbH, Danzig. Ordered 6 novenmber 1943, Launched 27 juli 1944. This XXI type could be driven by diesel drive and electric drive. Diesel 4000 PS and 3700 KW electric drive. It had 6 bows torpedo tubes. It was part of the 8th U-boat Flotilla. Identification number M43 302. Commander was Oberleutnant Hugo Deiring, from 9 september1945 till 8 may 1945. Crewmembers total of 57-60 men.
The radio room of the U 3503 after she was raised in 1946. All in pretty well condition. Off course the salt water did had his influence. To be seen on this picture the E52 Köln in the mid and also the LO40K39 transmitter above. In most XXI type U boats, there were often 2 equal type Köln’s. Although the equipment in the XXI type were not always the same till the end of the war in 1945. On the picture probably a n E52-b type? There exists not so many photographs of radiorooms in submarines. So this one pretty rare.
Another picture of the navigation room of the raised U 3503. Here to be seen at the left-mid, the very rare T 9 K 39 receiver. Was used for as a spare receiver.
The location of the radio- and navigation room were located in the same room, in the direction of the “Heck “.
Also a pretty rare picture.
The U 3503 was sunk after an attack of an allied B-24 bomber airplane in 1945, west of Gothenburg, Sweden, in the “Kattengat”. Location 57 degrees and 39 minutes N and 11 degrees and 44 minutes E. The wreck was raised in 1946 on demand of the Allied governments. Her crew was taken up during the sunk by the HSwMS Norrköping and interned at Backoma interment camp. So only about one year, it was really in service.
The technics:
The E52 is a superheterodyne receiver.
What makes this receiver so special are 4 things:
1)
The receiver has a total of 3 IF stages. The 1st IF stage has a total of 6 IF bandfilters. The 2e IF contains a variable x-tal bandfilter, so in the 3th stage. The variabel bandpass can be tuned from 200 Hz till 3 KHz. This makes it very suitable for receiving CW signals. See pictures below.
Band width wide. Picture website LA6NCA.
Bandwidth small, picture website LA6NCA.
2)
The frequency stability is very special and very good. Only 50 – 100 Hz, I noticed on my receiver, and that from starting up till 1 hour afterwards!
3)
It has also a motordrive, which switches automatically between pre selected frequency channels. There are 4 channels. To be used in all frequency bands. The Germans called it “Rasten”. The accurately of the chosen frequency, when you switch back to the former frequency channel is amazing.
4)
It has 2 frequency scales, a mechanical one and an optical one, a scale projected on a glass mirror, projected by an internal illuminated glass disk with all frequency scales. The projection is lead through several mirrors on the glass frequency mirror at the front of the receiver. So that makes it very accurate in reading the chosen frequency. It is amazing. After the war the Russians used it also in their receivers. Even a copy was made of the E52 by them.
I obtained it from a legacy. The family said, that it should go to a user and also loves these old german equipment. So it went to me, lucky I was.
The E 52 is one of the objects I liked to own, for at least 20 years now. So this was the chance to obtain it.
It was in well working condition. Only a few little errors were there. First the motor drive did not work. But that was easy to repair. The cause was a slipping knob on the “Rast” switch shaft. So easy to repair. The second problem was the mechanical readout of the frequency band.
So I had to remove the frontcover with all the knobs. It stated out that the subfront, where the readout was placed behind, was dented at the position of the readout window. So the readout was interrupted by this dent. So was also easy to repair.
So the faults were easy to fix. I was glad about this, because the E 52 is a very complex receiver. Especially the motor drive.
The E52 a placed on an ex-DDR receiver, the EKD 514. Also a top receiver. At the right the German HA5K39 with powersupply. Picure taken in my radio shack.
Another picture in a different perspective.
The famous accurate frequency scale. A projection scale on the glass mirror. Note that, that the glass light bulb has to calibrated in position to get more focus.
The mechanical scale with different colors for each frequency band. in this picture the frontpanel was removed.
The frontpanel removed from the receiver. Another one then mine. Here to be seen the frequency coverage of the receiver.
The back of the frontcover of the E52 a. At the right the shaft bushing of the frequency band. At the left the one of the channel selector. The shafts actually slide into the bushes.
Here above the optical frequency projection system. In the mid an optical lens. Behind that a mirror. The disk in the mid is the projection scale. At the edge of that disk, you can see the the very small strokes of the readouts of the various frequency scales. It is amazing, that they could make such things. The width of each stroke is about 2 mm, with with in the scal text!
In front of the optical lens a little lamp is positioned. This light bulb is very special in construction. Not every common 12 v light bulb could be placed. Mechanical (bajonet type) might fit, but bad focus etc. will happen etc..
Its light goes through the lens, and them through the glas disk with frequency readout to the mirror in the background. Then the light with a projection of the frequency scale is reflected and projected to glas mirror at the front of the receiver. An amazing system.
Will be continued.