I have a vintage motel pay radio I am trying to fix. There is a label on the back that has Radio Corporation of America and Hazeltine Corp and a stamped number on the chassis 4800. It is a five tube AM radio with no transformer. I have replaced all the tubes to restore filament voltage. (they light up at least). I replaced all of the paper capacitors and one small electrolytic. Have not replaced the 4 section power capacitor. I am trying to find a schematic to understand the voltages at each tube or to show components. Some resistors are well faded. My wife insists on fixing it before we put it up for sale. Currently low hum in speaker and some scratchy sound when tuned. The tubes are 12SK&, 12SA7, 12SQ7, 35L6GT, and 35Z5GT. Any help locating a schematic for this type would be appreciated.

:I have a vintage motel pay radio I am trying to fix. There is a label on the back that has Radio Corporation of America and Hazeltine Corp and a stamped number on the chassis 4800. It is a five tube AM radio with no transformer. I have replaced all the tubes to restore filament voltage. (they light up at least). I replaced all of the paper capacitors and one small electrolytic. Have not replaced the 4 section power capacitor. I am trying to find a schematic to understand the voltages at each tube or to show components. Some resistors are well faded. My wife insists on fixing it before we put it up for sale. Currently low hum in speaker and some scratchy sound when tuned. The tubes are 12SK&, 12SA7, 12SQ7, 35L6GT, and 35Z5GT. Any help locating a schematic for this type would be appreciated.
:
Bill
Google AA5 radio schematic, then click on wa2ise's Home Page of Radios, then click on the "red" text toward the top of the page that says "Click here to see two AA5 schematic diagrams." It will then show a schematic of your radio and chances are you will need to replace the filter capacitors in your set. Good Luck.

RCA and Hazeltine were radio technology patent owners to whom radio manufacturers who licensed their intellectual property were required to pay tribute... so the sticker on the radio is probably not an indicator of who actually manufactured your radio.

Most of these 5-tube sets were very similar. It's a good idea to replace the electrolytic caps on these sets, since, unlike most other parts in the set, they can go bad just sitting around.

Assuming it is a late 40's RCA, from the tube lineup, something like this? 2 hours for 2 bits!

http://www.ebay.com/itm/RCA-Coin-operated-radio-1947-Ad-specifically-engineered-/200979667841?pt=LH_DefaultDomain_0&hash=item2ecb525b81

The odd shaped and collectable pillow radios were made by Dahlberg, but I don't think you have one of those.
What those guys said, the voltages will sort themselves out if the tubes are good and filter caps are replaced.

:http://www.ebay.com/itm/RCA-Coin-operated-radio-1947-Ad-specifically-engineered-/200979667841?pt=LH_DefaultDomain_0&hash=item2ecb525b81

:

Here's the schematic for that RCA Model MI-13174. Unfortunately this one is a 6 tuber.
http://www.nostalgiaair.org/PagesByModel/545/M0015545.pdf