U-Boat Radios

I am researching the U-boats that ended up in the hands of the Canadians and Americans after the end of WWII.

These surrendered U-boats were allocated to the U.S. or Britain/Canada for study and afterwards were destroyed (typically sunk). The U-505 was saved on a “technicality” - it was captured, not surrendered.



U-505 (captured)











I want to identify which radios were on board each U-boat (there were a few different model receivers). Also I’d like to help identify any radio that was possibly taken from any U-boat. Below is a list of radio communication equipment used on WWII German U-Boats (from http://www.uboatarchive.net/KTBNotesCommunications.htm)

Below is a picture of the radio room of U-889, a type IX U-boat. In the picture on the right, the Telefunken E437S HF receiver is located near the desk lamp. To the left of the receiver is the Telefunken 200 watt HF primary transmitter.


The hydrophone or listening room also served as the backup radio room and in this room the spare (backup) HF receiver and transmitter were located. Below is a picture of the hydrophone room of the U-995, a type VII U-boat:

The Telefunken E381S backup HF receiver can be seen in the front center of the picture above. The E381S is similar in shape to the earlier E381H ("Zeppelin") receiver which does not have a meter on the front center.  More info on the E381S receiver can be found here.

The E381S receiver was used with the Lo40K39 40 watt HF transmitter which can be seen mounted on the right wall along with its power supply. This transmitter served as the backup or emergency transmitter on WWII German U-boat and as the primary transmitter other ships on other ships and some ground stations (and was also used by the other services - Army, Air Force). 

More Lo40K39 information and pictures can be found here.

Here's a front view of the Lorenz Lo40K39 transmitter (not shown is the matching power supply):

Also in the hydrophone room picture above, the receiver on the right is a rather large example of an entertainment radio that was used to pipe news and music throughout the boat.

A E437S receiver can been seen on the left, though this receiver was typically installed in the radio room proper.

Below is a closeup picture of this E437S - note the red lightning bolt symbol and the clock built into the front panel. Also this receiver has more permanent labeling for each knob (mine are paper labels in metal frames). Also this receiver has the vented cover on the top that allows the heat from the tubes to escape while keeping condensation out (mine is missing).

If you read German, email me for a pdf of the E437S manual.

A E437S can also be seen in use behind the U-124‘s radio operator in the following picture:


If you scroll down on this same webpage you can see another picture of a radio operator on U-129 actually operating a E437S.


I visited the U-505 in Chicago's Museum of Science of Industry some years ago but on the day I was there the radio room was closed for cleaning and I could not see the radios or the Enigma machine. I always assumed that the U-505 had a E437S on board but only recently thanks to the two documents below did I learn that a T9K39 HF receiver was actually on board (and is “missing”):

I’d like to find similar documentation about the other surrendered U-boats. 

Please email me if you can assist in any way!