02-01-2014, 05:05 PM
OK, Perhaps someone here with more first hand experience with your particular model can chime in here.
When I go to nostalgia air all I see is model 18 code 124 so I don't know if that's close enough to your radio or not.
What I meant by line voltage was indeed the AC voltage at your wall outlet. Did you actually measure it with an AC volt meter? If not, you should check it. It does vary somewhat regionally.
If you are only getting 5.9v instead of 6.3 for the filaments that sounds a little low but it may be in tolerance for that radio, I'm not sure. It is a bit strange that your B+ is high but your filament voltage is low.
Some radios have a switch on the AC line input for line voltage (ie 110v or 120v). The schematic I just looked at does not have such a switch.
I assume you are using some kind of fairly accurate digital multi-meter to measure these voltages?
I think there is something wrong somewhere if the signal dramatically gets louder if you probe those grids. Have you done any kind of alignment on the radio? I see there is a trimmer cap (#5) on the RF Amp grid LC tank and another trimmer (#10) on the 6A7 grid tank. I can imagine if those are off then the front end gain will not be what it should be.
So, without being there in person it's hard to troubleshoot via postings but these are the kind of things I may look at if you are having low signal levels.
Herb S.
When I go to nostalgia air all I see is model 18 code 124 so I don't know if that's close enough to your radio or not.
What I meant by line voltage was indeed the AC voltage at your wall outlet. Did you actually measure it with an AC volt meter? If not, you should check it. It does vary somewhat regionally.
If you are only getting 5.9v instead of 6.3 for the filaments that sounds a little low but it may be in tolerance for that radio, I'm not sure. It is a bit strange that your B+ is high but your filament voltage is low.
Some radios have a switch on the AC line input for line voltage (ie 110v or 120v). The schematic I just looked at does not have such a switch.
I assume you are using some kind of fairly accurate digital multi-meter to measure these voltages?
I think there is something wrong somewhere if the signal dramatically gets louder if you probe those grids. Have you done any kind of alignment on the radio? I see there is a trimmer cap (#5) on the RF Amp grid LC tank and another trimmer (#10) on the 6A7 grid tank. I can imagine if those are off then the front end gain will not be what it should be.
So, without being there in person it's hard to troubleshoot via postings but these are the kind of things I may look at if you are having low signal levels.
Herb S.
