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Hi Ron and all,
I can't seem to find the schematics that were on the original philcoradio site, and I need one for my model 90, with the single 47 output tube. Could someone direct me to the location on the Phorum where I can find the schematic? They are the best I've seen. I need to know the values of the bleeder resistor 58, as well as the DC resistance of the field and output transformer primary, since my speaker's transformer and field are both open (along with the broken cone). Could someone please point me to the steps I need to obtain the schematic for the 90? Thanks so much, all...
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This might help for now.
http://www.theoldradiofixerupperguy.com/...odel90.pdf
I believe Ron is in the process of moving the schematics to the new Phorum format.
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I believe the speaker info is in the speakers zip file here:
http://philcoradio.com/phorum/showthread.php?tid=215
My phone doesn't unzip files so I can't check at the moment.
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(08-29-2016, 08:55 AM)Chuck Braun Wrote: Hi Ron and all,
I can't seem to find the schematics that were on the original philcoradio site, and I need one for my model 90, with the single 47 output tube. Could someone direct me to the location on the Phorum where I can find the schematic? They are the best I've seen. I need to know the values of the bleeder resistor 58, as well as the DC resistance of the field and output transformer primary, since my speaker's transformer and field are both open (along with the broken cone). Could someone please point me to the steps I need to obtain the schematic for the 90? Thanks so much, all...
Hi Chuck,
Welcome
You may want to keep your eyes peeled for the model 70 spkr. It will replace the 90 spkr or a model 20 spkr will work also but the transformer is for push/pull output so you'll need to swap it for a 7K unit.
Terry
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
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Thanks, guys! On this particular set, cap 24 has only 3 sections, with the detector amp plate decoupling section added to cap 30, which has 3 sections rather than the 2 on the diagram. Just mentioning it as an observation; I'm sure this seemingly undocumented change is already known to exist.
I have a model 70, and used it to test my 90 after the recap, and now I know which speaker to look for. I think the dead speaker that came with the set looked just like the tinny one in the 20 I used to own. There was an open on the RF plate due to the RF primary being open, so I temped in RC coupling. Even so, without an antenna this set pulled in most of the locals like a champ. And I like it because it has a discrete oscillator rather than the troublesome autodyne circuits found so frequently on Philco sets of that vintage.