89B Detector Coil Rewinding - Printable Version

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+--- Thread: 89B Detector Coil Rewinding (/showthread.php?tid=23285)

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89B Detector Coil Rewinding - rkristelli - 02-15-2022

I've been going through my 89B Code 123 (No run stamp, It appears to be a late 89B with the 77 oscillator). I was able to fix the antenna coil. The detector coil, however, had a bad primary winding , and underneath has the green corrosion on the bottom of the secondary winding (center tap to ground) . The secondary is open from the center tap to ground. I fear that the oscillator coil is in the same condition, but I haven't removed it yet.

Has anybody rewound the secondary winding and recorded the turn count and wire gauge? How about the oscillator coil?

I appreciate your response. Knowing what I know now about the 89B, I would have looked at something else, but the cabinet is in decent shape, even the grille cloth is in good shape. I look at it as a challenge, now.

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RE: 89B Detector Coil Rewinding - radio1 - 02-15-2022

On that second pic, might be able to re-wrap just the lower part of the winding (before taking it all off, worth a try - top 90% looks okay). Wrap a round of painter's tape just above the bad section to hold it, and solder in 34  awg after removing the bad wire, and wrap the new down into the feedback coil, check ohms, and if necessary, replace the 15 turns of the feedback - might get it back in order.

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RE: 89B Detector Coil Rewinding - Radioroslyn - 02-15-2022

https://philcoradio.com/library/index.php/shop-talk/techniques/rewinding-philco-coils/

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RE: 89B Detector Coil Rewinding - rkristelli - 02-16-2022

Thanks for the info, everybody! I'm going to take a chance rewinding the bottom half of the secondary and the primary.

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