Sorry for the multiple posts. Microsoft Live Mail was telling me the message
could not be sent.
I cleaned the selector switch, the volume control, and tube sockets with
deoxit. No change. It is functioning like a 4 tube radio and I can change
the stations and hear them in two of the three "phono" positions. I noticed
it is coming through the phono input connection. If I short it, there is no
sound. Though why it does not happen in all three phono positions is not
clear. I have not replaced the caps in the tone circuit so that may be the
reason.
I did alter the b + connection so when it is in the phono position no b +
goes to the converter tube and that stopped it.
David
"nesesu" wrote in message
news:70e29e89-64b7-4148...@googlegroups.com...
On Friday, December 28, 2012 8:45:08 PM UTC-8, Brenda Dyer wrote:
> "David" wrote in message news:I checked the b + and it was around 94 volts
> in the radio position. When I switched to the first phono position the
> voltage dropped to .2 volts and I do not hear any radio but when I go to
> the next two tone control settings the voltage stays at .2 but I hear the
> same radio station. Go figure. It is a lower volume but very easy to hear
> and my hearing is far from perfect. Quite a challenge it
> seems.. --------------------------------------------------------------------------------
> --------------------------------------------------------------------------------Are you sure it's the same station you have tuned in? Try tuning the radiowhile in phono mode, and see if it changes. It's possible that what'shappening is that the phono input is picking up a strong local station andthe first AF stage is detecting it.It's also possible that a strong station will give enough signal out of the1st IF transformer [from the plate of the 12BE6 that is running wide open]to leak around the 12BA6 and into the 2nd IF transformer and be detected,but I think that the schematic showed that the AF into the 12AV6 wasselected from the phono, so that route is a stretch. With David's response,I was also leaning towards Brenda's suggestion.I surmise that they left the 12BE6 powered to keep it hot and minimize LOdrift when switching back to radio, other wise it would be sensible to cutoff the B+ to the 12BE6 on phono, as well.Neil S.