[ARC5] Very Interesting WWII German Transmitter

[David Stinson]

I recently acquired a WWII German transmitter that may be more significant
than it at first appears.  Type S23b, it's a simple power oscillator,
built in a wooden box, operating  at about 1 mHz and
 keyed by a motor-driven code wheel:

http://home.netcom.com/~arc5/s23b/004.jpg

Here's a close-up of the tag:

http://home.netcom.com/~arc5/s23b/plate.JPG

It's likely the unit was designed as a direction finding beacon.
The keying wheel produces a long dash followed by a
very slow Morse "K".

http://home.netcom.com/~arc5/s23b/001.jpg

Here's where it gets interesting.
The rig uses a latching relay to turn it on:

http://home.netcom.com/~arc5/s23b/002.jpg

+24 volts to connector "III" (both connections
are independent of ground) latches the relay.
There is also a push button/rod, marked "K,"
that will latch the relay manually:

http://home.netcom.com/~arc5/s23b/009.jpg

It's not a "K-eying" button; it pushes the relay armiture
to it's mechanically latched postion.
Once the relay has been latched "On,"
there is no way to unlatch it, other than to
disassemble the transmitter.  There is a second set
of relay coil contacts, designed to "unlatch" the relay,
but they are not connected.  The manual push-rod
does not provide a means to unlatch the relay, either.
Once this unit is activated,
it is not designed to be de-activated.
What ever it was doing, it was a one-way trip.

Here's a schematic:

http://home.netcom.com/~arc5/s23b/schematic.JPG

All this got me thinking:
The U.S. copied the V-1 for testing after WWII, called the JB-2 "Loon.":

http://www.warbirdsresourcegroup.org/LRG/images/lrg0024.jpg

It included a DF homing transmitter, (T-13, I think),
of which I have an example in storage.
It has a more sophisticated circuit,
but is the same form factor and code-wheel keying function.

Here's a reference to DF transmitters being installed in V-1s,
from web page:

 http://www.fighterfactory.com/airworthy-aircraft/buzzbomb-v1.php

"...V1's were originally launched from northern France ....
Approximately the first ten percent of each day's launches
would contain a small radio transmitter that emitted a signal
when the missile approached within thirty kilometers of its intended 
target...."
"...The only known radio homing device to have survived and still exist 
today
 is in this particular V1 (Fighter Factory's)..."

Also, from:
http://www.axishistory.com/index.php?id=1362

".... Some of the V-1s were fitted with a radio transmitter and a trailing 
antenna wire
 so that their flight could be monitored. In some cases, the bombs were 
"shadowed"
 by fast aircraft like the Messerschmitt 410 to observe their flight...."

The kind folks at The Fighter Factory in Virginia Beach, VA,
have agreed to take a look inside their V-1 (and V-2!)
and see if they can confirm my suspicions.
Looking forward to hearing from them.

73 Dave AB5S