Home » Audio » Radio » Edison type 7R (tube radio)
Edison type 7R [message #63224] Mon, 21 June 2010 21:27 Go to next message
ilikemac83 is currently offline  ilikemac83
Messages: 9
Registered: June 2010
Esquire
I have an old Edison 7R that I found a schematic for but shows 6 tubes where I have 5 and shows many other things that I don't have, like a phono plug. The schematic I found is here http://bentongue.com/edison/Service_manual_for_Edison_Radios_R6_R7.pdf
Was wondering if anybody has a better schematic or info on it. The main problem I have is getting into several metal boxes pined to the chasis that contain bad capacitors that I need to replace, assuming I can figure out what type of capacitors they are.
Re: Edison type 7R [message #63226 is a reply to message #63224] Mon, 21 June 2010 21:34 Go to previous messageGo to next message
Wayne Parham is currently online  Wayne Parham
Messages: 18790
Registered: January 2001
Illuminati (33rd Degree)

Wow, that's cool! But I'll bet it's a booger to align.

What tubes are missing? I wonder if it has been completely rewired, maybe even made into a newer circuit type.

Once I had a Stewart Warner radio that had been rewired to make use of an alternate output tube. I'm sure a repair shop rewired it to make use of a tube they had in stock that had different pinouts.

Re: Edison type 7R [message #63227 is a reply to message #63226] Mon, 21 June 2010 21:42 Go to previous messageGo to next message
ilikemac83 is currently offline  ilikemac83
Messages: 9
Registered: June 2010
Esquire
Amazingly no tubes where missing when I got it, but I did replace 2 227's that read weak. And after replacing a very bad power cord and slowly bringing up the voltage I do get (and only get) a 60hz hum. So all thats left to do now it take a hammer to it or something so I can get to the capacitors inside the metal boxes. They are held on by what looks like non removeable pins since they probly thought nothing bad would ever happen to them old capacitors COUGH COUGH yeah riiight!
Re: Edison type 7R [message #63229 is a reply to message #63227] Mon, 21 June 2010 22:28 Go to previous messageGo to next message
Wayne Parham is currently online  Wayne Parham
Messages: 18790
Registered: January 2001
Illuminati (33rd Degree)

You said the schematic shows six tubes yet your chassis only holds five. I was asking what the differences were, what tube was missing or if the whole circuit (maybe even the whole chassis) is different.

Re: Edison type 7R [message #63230 is a reply to message #63229] Mon, 21 June 2010 23:13 Go to previous messageGo to next message
ilikemac83 is currently offline  ilikemac83
Messages: 9
Registered: June 2010
Esquire
Ah right! The schematic for the power supply is correct, however my receiver unit uses 5 type 227 tubes, has 5 sockets that even say on them 227. And the schematic shows 3 227's and 3 224's.
http://bentongue.com/edison/Service_manual_for_Edison_Radios_R6_R7.pdf

Ill post some pics of this unit tommorow if I have some time.
Re: Edison type 7R [message #63234 is a reply to message #63224] Tue, 22 June 2010 21:19 Go to previous messageGo to next message
ilikemac83 is currently offline  ilikemac83
Messages: 9
Registered: June 2010
Esquire
http://adam.ritchison.com/orp.html
I uploaded all my pics here
Re: Edison type 7R [message #63235 is a reply to message #63234] Tue, 22 June 2010 22:06 Go to previous messageGo to next message
Wayne Parham is currently online  Wayne Parham
Messages: 18790
Registered: January 2001
Illuminati (33rd Degree)

That is so, so cool! Love the cotton insulated wire. Chassis looks like it's in pretty good shape, just needs a little cleaning.

The 60Hz hum symptom is a pretty common one. It can mean just about anything. Could be as simple as coupling caps gone bad, and if they haven't been replaced, that's likely. I generally replace all paper/oil caps with polys, first thing. Could be a tube too, or alignment, but I'd start with the caps.

Do you have a tube tester? An oscilliscope?

Re: Edison type 7R [message #63236 is a reply to message #63235] Tue, 22 June 2010 23:03 Go to previous messageGo to next message
ilikemac83 is currently offline  ilikemac83
Messages: 9
Registered: June 2010
Esquire
Tube tester yes, but no oscilliscope. Just recently got me a variac too.
Re: Edison type 7R [message #63237 is a reply to message #63236] Wed, 23 June 2010 10:34 Go to previous messageGo to next message
Wayne Parham is currently online  Wayne Parham
Messages: 18790
Registered: January 2001
Illuminati (33rd Degree)

Well, OK, cool. You can check the tubes then. Your tester will test those tubes, I hope?

Swap the caps, test the tubes and make sure they're all good. Hopefully that will get her going...

Re: Edison type 7R [message #63242 is a reply to message #63237] Wed, 23 June 2010 17:42 Go to previous messageGo to previous message
ilikemac83 is currently offline  ilikemac83
Messages: 9
Registered: June 2010
Esquire
Oh yeah and the tubes in her do read good. But now getting them boxes off the chases held on by pins is another story. The cap's in them are so bad, wax leaked outa the boxes and onto the power supply Sad that took some cleaning.
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