Summary: solid progress but more work to do
Details:
?? Replaced all electrolytics with new
?? Replaced burned resistor R218 150 ohm in ENABLE line
?? Replaced damaged axial lead ceramic capacitor C250 .01 mfd bypass +13v to gnd with .01 mfd disc ceramic
Results:
?? On power up appeared to work very briefly, then original axial lead ceramic capacitor C251 .01 mfd bypass +13v to gnd began smoking vigorously
?? Powered down and replaced C251 with .01 disc ceramic
?? Powered up and no new smoke.
?? Now works as a VFO as one might expect except that freq does not lock; drifts lower very slowly
Notes:
?? I am guessing that the passage of time may have resulted in degradation of the original ceramic bypass capacitors voltage rating.
?? Will now go through the manual setup and troubleshooting procedures to identify the failure to lock.
Rick
K8EZB
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