On May 23, 11:00*am, spamtrap1888 wrote:
On May 22, 11:10*pm, "Phil Allison" wrote:

"spamtrap1888"

http://www.seekic.com/uploadfile/ic-...7173226815.gif

How do you tune the radio in that schematic?

** Like any receiver that uses a crystal oscillator.

* *By swapping the crystal.

* *Ask anyone with a RC model.

..... *Phil

So meatplow's proffered schematic is even more spectacularly
inappropriate to the OP's situation -- trouble shooting a nine-
transistor AM-FM radio from 1970. Which, as I recall, likely used a
variable capacitor for tuning.

Googling shows a schematic of the Transistor 305 is available for
purchase on radiomuseum.org

I actually have the book with this radio. It has a schematic but comes
up somewhat short when it comes to voltages and waveforms. And the
intermittent nature of the problem makes it so hard to troubleshoot.
The other night it played on my bench for over ten hours. It never
failed and sounded fine. I finally went over and tuned the FM to a few
other stations and they seemed to sound OK. I then switched to AM and
although I did hear some stations, it being late evening I would have
expected to hear much more. But I wasn't sure about this as the shop
is in the basement. I tuned the AM between 550KHZ and 1600KHZ at which
point the radio suddenly quit. The tuning capacitor is not the issue.
And the switches don't appear to be noisy either. The scenario about
tuning the AM and the set quitting seems a bit of a stretch to be a
coincidence but then I just don't know. Anyone have any theories on if
this might be a small clue here? Thanks for following this thread,
Lenny