Quote:
Originally Posted by jr_tech
Could you post a scan of the schematic? It is not clear how you "removed " The volume control. Did you substitute a fixed resistor, or is the grid of the next audio tube now "floating" ?
jr
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I don't have a scanner. I could take a picture of the schematic and post it, but the resolution of my cheap Radio Shack Flatfoto digital camera is so poor (1.3 megapixels) that the diagram may not be legible, even if supersized.
I took the pot completely out of the circuit; didn't replace it with anything. There was only one lead connected to the control when I removed it -- a white wire going to one pin of the 12AX7 preamplifier tube.
You mentioned substituting a fixed resistor for the 2meg volume pot. I haven't tried that yet. Would it work well enough to get some signal through to the preamp? I'm not interested in getting a lot of volume, just enough to prove to myself that the trouble is not being caused by an open output transformer or some other serious problem. This radio was made 45 years ago, so I'm not sure I could get parts for it today; even the volume control potentiometer itself looks like a very special part that would be difficult (if not downright impossible) to get at this late date, unless I were to salvage one from a junked MJ1035 -- and I don't have the room to store another of those radios here.