I have som info (including electrical diagrams, waveforms etc.) based on interviews of the german scientific staff after the war by the allied forces.


SuperKraut Wrote:
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> The signal had to be analog since there was no
> mobile digital technology at the time. Considering
> what Lerche did, the wire must have carried the
> sound, instructions for moving the sensor head and
> instructions for moving the rudder. The only way
> to do that is by multiplexing several analog
> signals, a well known telephone technology at the
> time.

This is correct.

> There should be quite a bit of information on
> Lerche in Roessler's book on German torpedoes
> which I have been looking for for over a year. It
> is out of print and the only edition was a few
> thousand copies.

My copy was printed in 2005, so I guess there's been a new edition since the original one? Anyway: It has a 3 pages on the LERCHE, with a couple of illustrations.


Don Baker Wrote:
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> Do you have any information on the characteristics
> of the signals being carried by the wire - that is
> - did the wire carry analog information back from
> the torpedo array to the sub - what kind of
> bandwidth was required? Again - what was the
> nature of the signals sent from the sub to the

The Lerche cable was made of a 0,45mm copper-cablewith 1,35mm insulation (igelite).
The following was transmitted to/from the torpedo:
a) DC steering signals
b) Control signal (200-300Hz)
c) Pilot signal (29kHz)
d) Acoustic signal (34,5kHz)


> torpedo? Was any kind of multiplexing used?
Yes, as answred bu SuperKraut above.