09-25-2023, 08:46 PM
Jim,
I do not "know" this radio...
The schematic gives me a clue and your description, something is not working correctly in the oscillator circuit .
Check the DC resistance of the oscillator coil, please use a VOM. It should closely agree to the published values. Lift one side of the 110pf mica cap #5 attempt to measure if you can looking for +-5 pf. Or, sub in a new 110pf dipped silver mica. Do not twist the old cap to measure. Cross check your cap measuring device with a new mica cap. Trust the new cap when comparing the old.
Any alignment adjustment that does not have an effect has a problem in its associated resonant circuitry, Bad coil(s) leaking condensers, dramatically changed resistors.
Any corrective work in the oscillator or RF, even pushing a wire out of the way, will affect alignment.
If there is a altered value of resistance in the oscillator coil AND there is a celluloid liner between the primary and the secondary, quite possibly there is corrosion to the coils...
From A. H. Ghirardis Radio Troubleshooter manual, note, does not address calibration errors...
Sorry, it is a snip of a poor PDF. Download and open in an image processor to enlarge.
If the tuning condenser is mounted on grommets, if these sag will that effect calibration?
Chas
I do not "know" this radio...
The schematic gives me a clue and your description, something is not working correctly in the oscillator circuit .
Check the DC resistance of the oscillator coil, please use a VOM. It should closely agree to the published values. Lift one side of the 110pf mica cap #5 attempt to measure if you can looking for +-5 pf. Or, sub in a new 110pf dipped silver mica. Do not twist the old cap to measure. Cross check your cap measuring device with a new mica cap. Trust the new cap when comparing the old.
Any alignment adjustment that does not have an effect has a problem in its associated resonant circuitry, Bad coil(s) leaking condensers, dramatically changed resistors.
Any corrective work in the oscillator or RF, even pushing a wire out of the way, will affect alignment.
If there is a altered value of resistance in the oscillator coil AND there is a celluloid liner between the primary and the secondary, quite possibly there is corrosion to the coils...
From A. H. Ghirardis Radio Troubleshooter manual, note, does not address calibration errors...
Sorry, it is a snip of a poor PDF. Download and open in an image processor to enlarge.
If the tuning condenser is mounted on grommets, if these sag will that effect calibration?
Chas
Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”
