Repairing LwEa (wreck)
by LA7MI Stein Torp, Bergen

reference pages:
n72 Feld.Fu.Bertha
n73 Feldfunksprecher b1 und c
n74 Vollständiges Schaltbild des Lw. Empfängers a (LwEa)

Receiver front and inside view

Repairing the 60.9kHz IF coils:
It was impossible to open the cans because of rusty screws and other. The screen house must be carefully cut with hacksaw and coils removed. The inner bakerlite holder removed. Count the turns. Wind new coil with 10x0.05mm litz wire. When the screen box is opened as described the screening wount work, therefore it was made a new cylinder of soldered copperfoil. Note that the coils have rather high Q-value and replacement seem not right to try. If inductance meter is available it might be an idea to measure the inductance, even before the coil is opened, it might turn out that the coil is right and the prosedure is not needed.
The BFO and detector coils were rewound with 0.13mm enamelled cu wire (suppose they are not so critical).

Lw.E.a. One of the IF filters. It is two similar IF-stages on 60,9kHz. The circuit is drawn such that the similarities/differences with Kw.E.a can be seen

LA7MI Stein Torp, Amatör Radio, Oktober 1985

I enjoy collecting these items and I will show them on my website for others to
enjoy. I am not interested in selling them, however - please do not ask.
Instead, I hope to help others who collect this type of gear and would like to
hear from them.


My page for LwEa = 22c