The instructions are not the clearest, I've included them in case although that may be off topic. L2 gets aligned at 98.2MHz @ 22.5kHz modulation but at an unknown level, I suppose you're right Brian this is probably at a very weak signal. Perhaps lower it progressively and adjust for best sensitivity ? Official spec is 0.9?V for 26dB SNR
I was wrong, the FM impedance is actually 60ohm. The 150ohm is actually the AM Tuner. My bad.
Note in the second steps they do not mention the dummy for the basic IF alignment, but then it is mentioned for the phase shifter and much of the rest. No specs are given for the dummy, I've looked into many other manuals of the same period and they still don't say what is inside, but we can learn the dummy is powered by 12V for FM alignment and has no attenuation (for AM no 12V and a 6dB attenuation). They call it dummy antenna or matching device sometimes. One thing is they list Meguro and Leader signal generator, both of which were 50ohms, not 60.
Considering my Marconi is 50ohm, i suspect this may be an acceptable mismatch? But Blaupunkt didn't think so?
While at it, really off topic this time, how exactly does step 4 of the Basic IF alignment works? "Use frequency adjuster of the signal generator to adjust the AM minimum" Change carrier to have minimum amplitude?
Thanks a lot for taking some of your time to answer my questions, really appreciate it.
