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#16
01-05-2013, 01:23 PM
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Where is that volume control wired in? If it operates filaments at all, sometimes it only adjusts those on an RF tube or two.
Hard to figure it out long distance without a schematic. Time to signal trace. Touch your plugged-in soldering iron to the grid terminal of the output tube. Should get speaker hum. If not, check everything from there to the speaker. Then touch grid of first audio tube and see if you get louder hum. Get the audio section working first.
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Reece Perfection is hard to reach with a screwdriver. 
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#18
01-05-2013, 04:54 PM
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Well I found one big problem.....seems like the speaker connection had only one wire going to it
 So I hooked a test clip up to the terminal that had the wire missing, and started poking around. I hit a spot and music came out of the speaker !!!Although the volume is not as loud as I would like it to be, it works. Tuned in different stations, volume control works. I still got that capacitor out of circuit, pic below.....not sure if it affects volume....it attached to one of the coils in the set. Any idea what value it should be???? Last edited by stusnyder; 03-14-2015 at 10:09 PM.
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#19
01-05-2013, 07:01 PM
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Great! You got it going. The other transformer you mention is probably the other interstage audio transformer. You'll have one between the detector and first audio, and then another between first audio and output. One of these is the one you found open.
To figure out that capacitor, which I guess IS a capacitor, you could try clipping in some different ones. In those sets the caps tended to be large sometimes. I'd start with an .001, then an .01, then a 0.1 and see what happens. If it keeps getting stronger try a 1.0. On second thought is this in the grid leak circuit? If so the classic value is .00025 mfd which is 250pf. You could use a mica or ceramic cap close to this value if indeed this is connected to the grid of the detector. Although with it out of circuit and the radio working, it must not be? If you know which of your '01A tubes had the strongest emission when tested, you could try that as the output tube. There is something else you could try. The 01A tube as an amplifier would like some negative grid bias which some sets provide with connections for a C battery. You didn't mention any such connections on this set. The audio output tube on your set has its grid returned to ground, either through a transformer or through the work around you installed (wasn't clear which of the two audio transformers was open.) In any case you can connect a C battery to the output tube. Lift the grid's ground return. Connect a 4.5 volt battery with the + side to ground and the - side going back through the transformer (or work around) towards the grid. This will give a negative grid bias which will reduce distortion and help volume. For the 4.5 volt C battery you can use three AAA or AA cells in series. You could use a holder from Radio Shack for them or just quickly solder them in series and tape them in a bundle as they will last shelf life; they are not called upon to provide any current. The '01A tube can handle up to 135 volts B+ but I'd get the grid bias C battery going before trying anything over 90 volts on the output tube. Once the C is going, see how the volume is. Then you could try 100 volts, maybe 120. You are not going to get ear-splitting volume out of an '01A no matter what. It would take a different type of tube in the output section for that.
__________________
Reece Perfection is hard to reach with a screwdriver.
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#20
01-05-2013, 07:15 PM
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I tried a 0.1 and it kills the sound completely. Tested all the tubes, 2 are in the ? zone, all others are in the lower good range. So I shuffled some around. Sound got alot better, loud enough to hear across the room.
That capacitor is still unhooked. I measured the old capacitor and got a reading of 0.13 uf. If I hook it back in, it also kills the sound completely. Last edited by stusnyder; 01-05-2013 at 07:18 PM. Reason: forgot to add something
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#22
01-06-2013, 07:32 PM
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There were 2 fiber board capacitors that I replaced. The can one I took apart. It had wax in it, most of it was laying on the bottom of the cabinet.
I replaced it with a 0.2 cap. That gave me the best results. Replaced the dial light ( it was missing ) So I consider it done  Just need to wipe down the cabinet with some howards.
Last edited by stusnyder; 03-14-2015 at 10:09 PM.
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