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Old 07-06-2008, 12:50 PM
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kbmuri kbmuri is offline
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Join Date: May 2006
Location: Fort Wayne, IN
Posts: 590
Thanks both for the info.

The full schematic is on nostalgiaair.org. It's a single-ended 6K6 output stage. All tubes are nos or test as so. Electrolytics are new. Still has all the paper caps at the moment.

I found a 550-ohm primary, 0.5-ohm secondary transformer, approximately the same physical size, in the parts bin. It was attached to the PM speaker in the background:


The new xformer is shown attached, the old one is loose (shown for comparison). The transformer mounted with the windings vertical rather than horizontal, otherwise it looks pretty authentic/original. Primary was 550 Ohms, secondary, maybe 1/2 an ohm or so (I'm using an analog VOM, just noticeably deflects the needle off of 0). I don't recall anymore where the PM speaker came from, but it's the same size as the one I'm fixing, so hopefully the transformer is roughly the same power capacity.

The radio it will go into:


I want it to be a daily-listener more than a showpiece. I bet it will work as-is now, but just in case I blew the first transformer with a shorted paper cap, I think I'll play it safe and orange-drop the paper caps too. I don't see a third xformer around the junk bin...
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