Philco "Super 89" With 6A7 Tube - Printable Version
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Philco "Super 89" With 6A7 Tube - markmokris - 02-06-2017
Ron and all,
I can no longer find Ron's excellent procedure for converting a Philco Model 89 from the 36 tube to the 6A7 tube thereby making it a "Super 89". There used to be a tech tip that detailed how to rewind the oscillator coil and everything. Now I can't find it!
Help! Can anyone tell me where it is?
Thanks!
Mark K8KZ
RE: Philco "Super 89" With 6A7 Tube - Ron Ramirez - 02-06-2017
http://philcoradio.com/phorum/showthread.php?tid=14919
RE: Philco "Super 89" With 6A7 Tube - Steve Davis - 02-06-2017
About a year I had a Philco 19 on the bench. The oscillator would die out on the upper end of the band. I tried all the things we do in a case likes this. I tried different 36 tubes, baked the oscillator coil and lowered the value of the cathode resistor. This was the first time one of these things beat me. I'm really thinking about getting the chassis back down off the shelf and doing Ron's "super mod" on it.
Steve
RE: Philco "Super 89" With 6A7 Tube - markmokris - 02-07-2017
(02-06-2017, 05:49 PM)Ron Ramirez Wrote: http://philcoradio.com/phorum/showthread.php?tid=14919
Thanks Ron! I couldn't find it anywhere.
I have experienced the same thing as Steve. I have done three of these now. Generally, I managed to get them to work with the 36 tube, but it is a real crapshoot. You can do all the steps, and it still maybe not work completely. The whole thing is real unpredictable.
Recently I posted that I made the switch to the 77 tube, and that did work well. I have another 89 sitting here to restore. If I have trouble with that one, I may go right to the 6A7 conversion.
I have couple spare coil forms so I would not have to destroy the original from the radio.
Mark K8KZ