Home  Resources  References  Tubes  Forums  Links  Support 
RCA R-7A Nightmare is over.
3/4/2012 6:16:17 PMDave Froehlich
Hello All,
The big problem was that R8 was disconnected from the cathode of the detector tube. The other problems were that the leads to the IF transformers were shorting against the metal can where they exited from it because the cloth deteriorated.
Why someone would cut that wire, I have no idea. It was done many years before the late 70s when I got the radio. The chassis says Westinghouse WR-10A on the back of it and it's in a tall "Columnaire" cabinet. It looks like "Columnaire 12A" with an electric clock in it. WR-10A refers to a "columette" 10A which is normally in a Tombstone cabinet, just like the R-7A. So I have no idea what the model number of this radio is. But it's one of my favorites. It's going to look really good in my living room.

Dave

3/4/2012 11:55:44 PMDave Froehlich
Hello All Again,
I ran it for a while and it was working fine. Then it started to motorboat. I could see the gas in one of the 47s. I pulled the gassy one. The other is so weak almost nothing can be heard. So I'm going to have to get a pair of 47s some place before proceeding. I hear loads of heterodyne sounds when the radio is playing. So something is probably way out of adjustment.

Dave
:Hello All,
: The big problem was that R8 was disconnected from the cathode of the detector tube. The other problems were that the leads to the IF transformers were shorting against the metal can where they exited from it because the cloth deteriorated.
: Why someone would cut that wire, I have no idea. It was done many years before the late 70s when I got the radio. The chassis says Westinghouse WR-10A on the back of it and it's in a tall "Columnaire" cabinet. It looks like "Columnaire 12A" with an electric clock in it. WR-10A refers to a "columette" 10A which is normally in a Tombstone cabinet, just like the R-7A. So I have no idea what the model number of this radio is. But it's one of my favorites. It's going to look really good in my living room.
:
:Dave
:
:

3/5/2012 12:24:50 AMWarren
What happens if you swap the output tubes around? Does the weak tube play the same in the other socket?
3/5/2012 1:12:03 AMDave Froehlich
Warren,
I just moved the one weak tube to the other socket, and it's still weak. I don't want to put the gassy tube back.
I better just get good tubes.

Dave
:What happens if you swap the output tubes around? Does the weak tube play the same in the other socket?
:

3/5/2012 1:39:32 AMWarren
As long as the set operates the same with the weak tube in each socket, this indicates the bias is okay, and the B+ is divided to each plate. The harmonic problem could be the 2nd detector, tune shields in place? An alignment is needed anyway.


© 1989-2025, Nostalgia Air