Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

48-482 schematic
#1

I'm working on a 48-482 and I've run into a problem. The only schematic I have been able to find shows a 6SQ7 as the first audio even though all sets have a 7B6 in its place. I have a tube diagram for the 7B6 but it would sure be a help if I had a schematic that shows the 7B6.
Does anyone know where I can get one?

Thanks,
Eric

BTW. The problem is: squeal like feedback when turning up the treble control and with a long wire antenna I can only get one local station all over the dial. Has been re-caped. Tubes and resistors replaced as nec.

Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org

#2

Schematic here
http://www.nostalgiaair.org/PagesByModel...013637.pdf

Tube data here for 6SQ7, 7B6 and anything else you wish.

http://www.nj7p.org/Common/Tube/SQL/Tube...?Type=6sq7



Both tubes do the same thing, and often whatever was available was used in production and changes were not always documented.
#3

Thanks Codefox1, The schematic is the same as I have but the tube digrams are much clearer. Everything checks out at the 7B6. I guess it's back to the trouble shooting guide.

Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org

#4

There is a factory service manual for this model on this page although it also shows the 6SQ7. It is in DJVU format so you will need a reader.

http://www.audiophool.com/Philco.html

Sean
WØKPX
#5

Thanks Sean, that's the info I have now. I'm looking for something that shows the 7B6.

Eric

Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org

#6

Eric, AFAIK all the published prints show the 6SQ7, but the only difference is the pin numbers. That said, this weekend when I have some time, I'll pull a working chassis and take some voltage and resistance measurements. Maybe we can pin down the problem that way.

John
Las Vegas, NV USA
#7

Thanks John, hope to hear from you soon.

Eric

Eric
The Villages, FL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org

#8

6SQ7

https://www.nj7p.info/Tubes/SQL/Tube_que...?Type=6sq7

If this link above doesn't work, go directly to NJ7P's website and enter the tube your looking for

Tube Database Website:

https://www.nj7p.info/Tubes/SQL/Tube.php
#9

The schematic in the Philco Radio Library accessed at the bottom of the Home page shows the 7B6.
https://philcoradio.com/library/index.ph...year-book/
Take care and BE HEALTHY! Gary

Thought I'd point it out, even though the thread is 11 years old!

"Don't pity the dead, pity the living, above all, those living without love."
Professor Albus Dumbledore
Gary - Westland Michigan
#10

EagleRiverMike,

Welcome.

I use Bill's (NJ7P) SQL tube database query all the time - it's much easier than getting out one of my tube manuals.

But I should mention this thread is 11 years old, and the OP (original poster) hasn't visited here in nearly two years (I hope he's ok).

--
Ron Ramirez
Ferdinand IN
#11

Guess Ron and I commented simultaineously! Take care and BE HEALTHY! Gary

"Don't pity the dead, pity the living, above all, those living without love."
Professor Albus Dumbledore
Gary - Westland Michigan




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Shadow Meter Bulb
Phorum members, I am trying to find the bulb # for PHILCO Shadow Meter part number 45-2180 that is from a 37-640 chassis...georgetownjohn — 06:53 PM
Philco 41-608 changer coupler
3D-printing...short of machining, of course. Or molding.morzh — 05:20 PM
Philco 41-608 changer coupler
Thanks, Morzh. That solves the issue of the rubber pieces. Now, I need to find a way to replicate the pot metal piec...alangard — 05:07 PM
12' Philco
If it is 12', either Kareem or Andre would have to jump pretty high to look at the front panel. Kareem would have an e...morzh — 01:48 PM
12' Philco
And here's a story about the tires on the truck. Same "no-stoop" guy must have installed these! Take care a...GarySP — 01:17 PM
Hickok AC51 tube tester
I think they have only shown the secondaries of the transformer. Two of them feed the rectifiers' filaments.morzh — 12:58 PM
IF can wire size and Rubber mounts?
Arran If the wire inside cans is the gauges you mentioned, the sole reason for that would be mechanical, to stiffen t...morzh — 12:56 PM
12' Philco
Rod, Yes, I know, but the Giant Philco is not around anymore either, so I go by whoever was alive fairly recently. H...morzh — 12:54 PM
Hickok AC51 tube tester
Absolutely no one is going to reverse engineer that circuit. Even the iron core is missing.RodB — 10:37 AM
IF can wire size and Rubber mounts?
Thanks to both members for your help regarding wire and tuner mtg supports. regards--Johngeorgetownjohn — 09:33 AM

[-]
Who's Online
There are currently 6022 online users. [Complete List]
» 1 Member(s) | 6021 Guest(s)
Avatar

>