26-12-2016, 12:01 PM
(26-12-2016, 10:24 AM)Murphyv310 Wrote: Regarding your fault ... it can only be switch (4,5 & 6) contact ...
Further to Trevor's post, contacts 4 & 5 are OK, as is the sliding contact, or FM wouldn't work so only contact 6 can be a problem.
Unless it has suffered some physical damage - highly unlikely - the problem almost certainly* lies elsewhere, and Trevor has listed all the alternatives.
Interesting that the set uses the US standard AM IF of 455kHz. As we know in the UK, this caused problems with the reception of the Home Service (908kHz), later Radio 4 (909kHz) due to beats with the second harmonic of the IF. Interestingly, there was a high power transmitter at Burg, near Magdeburg, in East Germany, used for propaganda broadcasting to West Germany that would have caused the same problem!
Also interesting is the multi-lingual footnotes - including English - on the circuit diagram.
Now that is possible to see how the drive cords are configured, I can say that they are a doddle compared with the horrific Philips arrangement I had to contend with in the 60s!
* There is, I suppose, the possibility that the set has been used solely on FM for an extended period of time and a substantial amount of tarnish has built up on contact 6 but, obviously, this will only need to be investigated if there is no HT present on the 'hot' end of R12.
