The PHILCO Phorum

Is there a service bulletin noting the circuit differences between the model that uses the 6A5G vs the 6B4. Is that model distinguish by a code number other than 121 or 122?

Terry,

It says the changes are in Philco 8-3.
I haven't seen anything there specifically about 37-116.

I know we had discussed it a little ways back when you got
your set.
Looked up the pin out and kinda interesting as the cathode is
internally connected filament at it's mid point. I would have
thought that it would have a separate pin with no relation to
the filament. Does your set have have a filament balancing
or hum adjusting pot?

Terry,

Don't want to misinform you, I do not remember. There might have been no trimpots in mine. Mine is 6A5 version.

Now that I think about it, probably there were no trimpots.

the two spare chassis' I have are 6B4 types. Probably same as yours.

Terry

here.
https://philcoradio.com/phorum/showthrea...ght=37-116

My old thread.

Look at the comment #47 by JohnR.

This has both Service Bulletin # and the pot (#128) removed.
I guess it is a dual pot, as both pots have the same number.

Funny...in the mentioned SB #258 I found nothing about codes 125/126.

Tnx Mike,
I thought that was the case but wanted to be sure.
There's a poster on arf that was asking abt the differences.