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40-201 oscillator not working.
#6

Hi Terry,


We are both circling the same questions, I've checked them all once already but I'll do it again to see if there is something I have missed. You say that the HV side of coil 28, pins 3 and 4, are the feedback circuit. Thanks, but is that coil or winding simply a choke? Or has it been tuned to a specific frequency necessary to make that circuit oscillate? Why doesn't that extra resistor across that coil also provide feedback for the plate?  If I unhook that coil but leave the resistor in place I lose my B+.  I am going to check that again too.  That winding measures about 1 ohm.  The broadcast oscillator coil, #26, measures about 6 ohms.  
I assume the main tuning cap on the oscillator side is working, because during the test you had me perform where I used my SG as an oscillator, I was able to rock on and off the station by moving it. I'll make a specific test to capture the specifications. I have an accurate, dedicated capacitor checker. I've used it to measure the capacitance of that main capacitor already. I'll do it again and share the results.
Also, I have used clip leads to jump around the various contacts on the selector switch to be certain that they are all working. I have cleaned that switch. 
I'm waiting on parts.  I have ordered all new mica caps for the 100 Pf as well as the other two 250 Pf caps, #6, #14, #32.  All of them are out more than 20%.  As I already mentioned I have also ordered 2 adjustable oscillator coils.


Tom


Messages In This Thread
40-201 oscillator not working. - by Tomie - 04-30-2020, 04:15 PM
RE: 40-201 oscillator not working. - by Tomie - 05-11-2020, 11:19 AM
RE: 40-201 oscillator not working. - by Tomie - 05-12-2020, 01:32 PM
RE: 40-201 oscillator not working. - by Tomie - 05-12-2020, 01:38 PM
RE: 40-201 oscillator not working. - by Tomie - 05-16-2020, 11:35 AM
RE: 40-201 oscillator not working. - by RodB - 05-16-2020, 12:33 PM
RE: 40-201 oscillator not working. - by Tomie - 05-16-2020, 02:26 PM
RE: 40-201 oscillator not working. - by RodB - 05-16-2020, 05:17 PM
RE: 40-201 oscillator not working. - by Tomie - 05-16-2020, 06:08 PM
RE: 40-201 oscillator not working. - by RodB - 05-16-2020, 07:02 PM
RE: 40-201 oscillator not working. - by Tomie - 05-17-2020, 12:57 PM
RE: 40-201 oscillator not working. - by RodB - 05-17-2020, 06:03 PM
RE: 40-201 oscillator not working. - by Tomie - 05-18-2020, 12:13 PM
RE: 40-201 oscillator not working. - by Tomie - 05-18-2020, 01:15 PM
RE: 40-201 oscillator not working. - by Tomie - 05-18-2020, 06:09 PM
RE: 40-201 oscillator not working. - by RodB - 05-18-2020, 08:43 PM
RE: 40-201 oscillator not working. - by Tomie - 05-19-2020, 01:54 PM
RE: 40-201 oscillator not working. - by RodB - 05-19-2020, 04:56 PM
RE: 40-201 oscillator not working. - by Tomie - 05-21-2020, 07:03 PM
RE: 40-201 oscillator not working. - by RodB - 05-21-2020, 10:03 PM



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