Bob in Phx wrote:
William,
thanks for the complement.
I am a firm believer in fix'in it myself. A classic tinker, but with a
doctors creed "first do no harm". I don't work on other folks stuff much,
just my own. I think I inherited native troubleshooting ability from my
maternal Grandfather. He was a real genius at fixing things... and the
things he fixed,,, stayed fixed. He passed away 15 years ago and I still
miss him. As opposed to my brother in law who is a classic non-handy man.
Wouldn't know the sharp end of a screwdriver. If its broke, pitch it in the
trash...... buy a new one... drives me nuts.

So back to the issue. Since this radio has a three gang AM tuner "front end"
board, I should be able to prove or disprove your/my new theory, by
injecting an rf signal somewhere between the Front end and the AM/FM board.
There is an interconnect schematic here

http://www.hifi-museum.com/lib/misc/...-sx-727_sm.pdf

No help for your problem, but wonder if your 727 is the one which was
stolen from me in the late 70's.

Not much chance, of course, but it was my very first 'real' piece of
high fidelity equipment, bought on an Pioneer salesperson discount, and
I still miss it. If yours has a splice in the power cord (the thief
couldn't be bothered to simply unplug it)....

I hope you get it fixed. The FM was super hot for the day, and the amp
section is very sweet. I didn't listen to much AM in those days, but I
remember it worked pretty well.

jak