What do we consider "vintage gear" these days?
Anything that vintage guys get nostalgic about.
On September 10, 2014 at 10:37, highfigh said...
Quite a few 5 pin rectifiers, too. 5U4, 5AR4/GZ34, 5Y3, 5R5, 5V4, etc.
Those all have octal bases. When I spoke of four pin, five pin, and six pin tubes such as the 80, 35 and 37, I was talking of tubes without the octal base... with ONLY those pins sticking down. The fatter filament pins were the only way you could be sure you weren't sticking them in rotated from the proper position, and a strong arm could get them in wrong.
Lots of contradictory info out there.
Re: your Philco- you could have looked at the tube manuals for rectifier info or a tube circuits book from Western Electric, RCA, ATT, etc.
I had them and I was familiar with them. I only have the Sylvania one today.
I doubt they used a proprietary circuit for much of anything and if it has/had a label inside like this link, it would have been easy enough. That is, if the internet was available. If you still have it,
I gave up on it around 1969. And again, the basic circuits weren't the problem. The problem was stability of the tuned RF stages, big-ass triode tubes amplifying over the range 540 kc to 1600 kc. (We didn't have Hertzes back then.)
