04-28-2012, 05:30 PM
The winding on the section of my oscillator coil that has one end connected to the cathode of the 36 Det. Osc. and the other end to the RC circuit to ground is supposed to read 5.25 ohms according to the schematic. Mine was corroded (imagine that) and open.
http://www.philcoradio.com/tech/89evol.htm
So I carefully counted the turns and came up with 26 trying to add in the couple of pieces that broke off while unwinding it. It's rewound taking notice of the direction, start and finish points etc. Now it reads about 2 ohms.
1. I don't understand why the bias for the cathode is going through the oscillator coil. If this is the bias for the cathode.
2. Why with the same amount of turns as the original and using the same gauge wire I only have 2 ohms and not 5.25.
3. The primary and secondary windings of the oscillator coil are much bigger (at least 100 turns each) and they read 5.07 & 5.7 ohms respectively. How can my little tickler coil with so many less turns on the form read about the same on the schematic? Primary & secondary do read about the resistances called out on the schematic.
I believe my oscillator will work just fine with my new winding but can someone answer the puzzles I mentioned above. And as a note I am trying to incorporate as many of the changes as possible to my 89 as pointed out in the notes that go along with the above referenced url that I imagine were drawn up by Ron R. Thank you Ron! Good info!
Pepper
http://www.philcoradio.com/tech/89evol.htm
So I carefully counted the turns and came up with 26 trying to add in the couple of pieces that broke off while unwinding it. It's rewound taking notice of the direction, start and finish points etc. Now it reads about 2 ohms.
1. I don't understand why the bias for the cathode is going through the oscillator coil. If this is the bias for the cathode.
2. Why with the same amount of turns as the original and using the same gauge wire I only have 2 ohms and not 5.25.
3. The primary and secondary windings of the oscillator coil are much bigger (at least 100 turns each) and they read 5.07 & 5.7 ohms respectively. How can my little tickler coil with so many less turns on the form read about the same on the schematic? Primary & secondary do read about the resistances called out on the schematic.
I believe my oscillator will work just fine with my new winding but can someone answer the puzzles I mentioned above. And as a note I am trying to incorporate as many of the changes as possible to my 89 as pointed out in the notes that go along with the above referenced url that I imagine were drawn up by Ron R. Thank you Ron! Good info!
Pepper
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