Total posts : 45366
I have a much better personality and set of values than that other Barry.
As for TP 1 I was thinking it was tied to the LC loading coil, that the FM 25B PLL would not lock into frequency unless the LC was receiving 5.0 Volts. Tuning these things is weird because as Neil said, sometimes the slug was sticking out of the top of the coil housing before the transmitter would be happy.
I see a sharp peak that disappears as fast as it shows up when using a volt ohm meter but after more careful tuning (often slow tuning) i would find the sweet spot and the LED would burn steady without modulation and then flicker if audio was at an acceptable level.
Maybe I am wrong about this, I have yet to see that 5.0 volts , it is closer to 4.8 ,4.9.
It could be the LC is worn from changing frequencies so often.
Carl thank you for your help scanning that manual, i looked again today but still could not find it.
email@example.com is a good email address if you haven’t already sent the file.
If it was to firstname.lastname@example.org that is fine as well.