[b71] Lorenz 6P203 Communication receiver

Links to pages for similar equipment:

b 72. Siemens Funk 745 E310 "Rainbow receiver"
b 73. Racal Ra 17 mods

Lorenz 6P203 communication receiver 1430-8800MHz.
It is an odd frequency range, perhaps it is constructed for short distance communications?


RX seen from below and above

RX block diagram

Partly circuit diagram for 6P203

Lorenz 6P203 AM/CW and AGC-detectors

Note that the IF is splitted, with two different last IF stages, one for CW/SSB detector and
another for AGC, so it is no problem to receive CW/SSB with AGC on. The only modification
needed, was to change the anode resistor for BFO from 220k to 33k to increase the anode
current and increase the BFO injection. Used it on many evenings listening to 3800kc, and I
am surprised that the audio quality for ssb is so well. Audio output stage is a 6AU6/EF94. The
receiver has also a remarkable good audio cw filter with bandwidth down to 0.3kHz.