This is a follow up to "67.5 power supply".
I went to Walgreens today and picked up a pack of six 9 volt batteries for $5. I hooked then in series with a 'C' battery holder from a portable radio and got 67 volts.
I get audio, but no stations. I've already tested the tubes. One tested weak, but that shouldn't keep it from operating. If you think repairing a small AA5 is tough, you should see this. It is MICRO -tiny. I may have to use wires to extend the tubes out to check voltages. There is NO way to get probes to the sockets.
Anyway, I love a challenge, and this is going to be one.
Terry

Terry,

Test all the tubes if you can. I had a 1L6 that had gone to air. The filament stayed intact but would not light but let the other tubes light. I would also suggest that you tape up the VOM probe lead except for the very tip. This can keep you from bridging across two connections and burning out a filament(s) by getting B+ shorted to the filament circuit.

Clifton

:This is a follow up to "67.5 power supply".
:I went to Walgreens today and picked up a pack of six 9 volt batteries for $5. I hooked then in series with a 'C' battery holder from a portable radio and got 67 volts.
:I get audio, but no stations. I've already tested the tubes. One tested weak, but that shouldn't keep it from operating. If you think repairing a small AA5 is tough, you should see this. It is MICRO -tiny. I may have to use wires to extend the tubes out to check voltages. There is NO way to get probes to the sockets.
:Anyway, I love a challenge, and this is going to be one.
:Terry
:

:Terry,
:
:Test all the tubes if you can. I had a 1L6 that had gone to air. The filament stayed intact but would not light but let the other tubes light. I would also suggest that you tape up the VOM probe lead except for the very tip. This can keep you from bridging across two connections and burning out a filament(s) by getting B+ shorted to the filament circuit.
:
:Clifton
:
Thanks Clifton. I checked all the tubes and they test good. It's going to as hard to get light on that top tube shelf as it is the probes. I'm hoping that it's an oscillator problem because that section looks easy to get to.
:
::This is a follow up to "67.5 power supply".
::I went to Walgreens today and picked up a pack of six 9 volt batteries for $5. I hooked then in series with a 'C' battery holder from a portable radio and got 67 volts.
::I get audio, but no stations. I've already tested the tubes. One tested weak, but that shouldn't keep it from operating. If you think repairing a small AA5 is tough, you should see this. It is MICRO -tiny. I may have to use wires to extend the tubes out to check voltages. There is NO way to get probes to the sockets.
::Anyway, I love a challenge, and this is going to be one.
::Terry
::
:

Terry:
Chk the local osc. If you have a scope just place the probe near the osc.

Also chk for plate voltage on the 1st 2 tubes to make sure the IF primaries aren't open.

The print shows slug tuned IFs .. are these the newer style with a common capacitor substrate?

:Terry:
:Chk the local osc. If you have a scope just place the probe near the osc.
:
:Also chk for plate voltage on the 1st 2 tubes to make sure the IF primaries aren't open.
:
:The print shows slug tuned IFs .. are these the newer style with a common capacitor substrate?
:
Anyway, this set of course has some extra challenges because of it's size. I've been thinking of replacing a couple of large paper caps just to make more room.
Oh well, back to bed and "FM Simplified". I'm still waiting for the "simplified" section.
More later-
Terry

Ok Terry... nothing much anyone can do for a cracked rob .. right.. except tape you up and go to bed...

Tripped on a zip cord?.... that'll teach you to organize the shop a bit maybe.

Though being in bed may help heal .. it does not always prevent cracked ribs...lol ..

In my case a GF once put my chest in a fun-loving leg-lock in bed ...and cracked my rib...
Is that called rough bed play or something?.. ouch!!

My chest hurt for weeks too. All she did was laugh and say she was sorry... yeah right...lol

Well keep us informed w/progress on the radio when you're up and about again Terry.