Quote:
Originally Posted by vortalexfan
OK so I took and hooked up my radio's original speaker up to the radio (I had to use an aligator clip lead with a mini banana plug on the end to hook one of the leads from the speaker up to the radio as the original pin plug was missing on one of the speaker leads and I powered on the radio and it actually worked (albeit with a loud hum) which I assumed was because the set needed neutralizing so I got my signal generator out and set it to 1400 KC and I was able to get the hum to partially clear up, but it still had some hum to it.
So I went to turn the radio off and check something out underneath the power supply to see if maybe a ground wire was loose or something, and there wasn't and so I went to turn the set back on again and now the output tubes aren't glowing anymore and there is absolutely no audio coming out of the speaker except for a little crackling noise when I wiggle the output tubes in their sockets.
I checked the heaters on the output tubes for continuity and they still have continuity but they for some reason just refuse to light and I checked the filiment winding for those tubes on the power transformer and its still has continuity (its not open or shorted).
I'm not sure what's wrong with this radio right now and I'm so close to getting this radio going I'm just not sure what's going on with this thing right now and why the audio section suddenly decided to take a dump on me.
Any ideas?
Also can a tube die and still have continuity on the heater pins? Just wondering because it seems weird that both of my output tubes would of died at the same time but I guess its not completely unheard of just really uncommon.
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If the 71 filaments aren't open they should still light. Did you measure the 71's filament voltage, both at the 71 sockets and wherever it exits the power supply?
Edit - Also, neutralizing a Neutrodyne has nothing to do with eliminating hum in the audio. It's purpose is to neutralize capacitance in the RF tubes. Hum is an entirely different problem. Did you replace the power supply filter caps like you planned?