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Fusprech.f sabotage!

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    Fusprech.f sabotage!

    It is not the first time that I have encountered evidence of sabotage in late ware radios, but I never documented it. I thought I try to document this example as a testament to the hidden heroics of an anonymous forced labourer.

    I was restoring a Fusprech f radio and was quite pleased that I got it back to work, only to be disappointed the next day. Although the radio still transmitted, for some reason it stopped receiving. I spend a lot of time measuring through all the circuits until I noticed that the oscillator valve did not get 12V heater voltage. Strangely when I measured the circuit with a multimeter it seemed to connect OK, so what was going on. It was only when I started digging deeper into the set and checking the wiring on the RL12P10 valve socket that I discovered that one of the wires had not been soldered on. It is impossible to see with the socket screwed in place, here I have loosened the valve socket and moved to one side a bit so so I could inspect the connections:

    <a href=""><img src="" title="source:" /></a>

    The two red wires on the right hand side carry the 12V filament voltage to the RL12P10 valve and onward to the oscillator valve. Only when I started pulling the wires I noticed that one was loose, it was just loosely twisted around the other wire. Here I have pulled the wire out:

    <a href=""><img src="" title="source:" /></a>

    There was no soldering tin on the wire so it had never been properly installed. The connection was done in such a way that it would pass factory and Wa.A acceptance testing, but when subjected to vibrations and rough handling in the field it would certainly have failed. There still just enough connection left to make my continuity tester work, but the connection would not conduct enough current to power the valve.

    I am quite sure this was done deliberately and it is a typical example of how forced labourers sabotaged radios in the factory. Very risky but also very difficult to find. This particular (late war production) radio probably never made it into operations, if it had it would certainly have failed and been discarded long ago!


    Last edited by Funksammler; 08-05-2018, 10:34 AM.

    Interesting example. I imagine there was a lot of sabotage happening in these factories during the war.

    I found a similar situation in a Kasten Pz. 20 where several of the connection terminals were improperly attached to the soldering loops and the connection was unreliable.