[knockbill]

[attachment=1493]hi guys,

i just joined, this is my 1st post....
i have a couple of 40's philco radio's that were given to me by a philco radio collector buddy,,, he's into older sets,,,

i started with this this pt-12, its recapped, and all teh tubes tested good,,i also replaced the cord set,,, it didn't work when i got it, and teh new cap and wiring didn't help any,,, someone was working on it before i got it, as half teh 20-20 lyctic was replaced with a single,,33mf, if i recall,,, this cap was just twisted on to teh old wire, no solder...
taht was my first clue to what i was in for!!!!!
i got a copy of the philco schematic , and also a rider one,, which is basically the same view,,, i can usually figure out a schematic,, but these have me stumped,,,,
are there any other schematics, or wire plans available that are easier to read? anyone restore one of these chassis, and have some clear pics? i'm pretty sure there is a miss wiring problem... any all all help with this will be welcome...

[Radioroslyn]

Nope That's going to be it. I suggest that you bone up on how to read a schematic. This is a very basic thing if you want to service your set. Also how count the pins on your tubes will be very helpful in troubleshooting.
Terry

[knockbill]

Yep,, thanks for your help... i can't read this schematic, because its not ledgable, and i did number and identify all teh pins...i just finished restoring a small amplifier, but the schematic was clear, and easy to read...
i'll try to find a clearer copy for the pt-12...

[Radioroslyn]

This one isn't too bad.
http://www.nostalgiaair.org/PagesByModel...014123.pdf
Terry

[klondike98]

Knockbill, If the one Terry pointed you to is not clear enough you should be able to get a very clear schematic from Chuck Schwark at http://www.philcorepairbench.com/schematics.htm . Only 7 bucks and well worth not having to guess at what the schematic values are.

[knockbill]

thanks terry, and klondike....

i have a copy of that rider schematic,, its small, tho,,, i'll send it to my son, and see if he can split it to fit on 2 pages so its easier to read,,,
thanks for taking the time to help me out,,,,
i did a lot of research,, and found a later schematic, 46-421, i believe,,, its a post war schem of my set, but has a different beam power tube (50L6, if i remember),, i was studying that one today, and checked out teh tubes' plate voltages... they all seem to be within 5V of teh schematics, so i guess i'm making progress...
i appreciate your input,,,trying to learn tube circuits....
regards,
john