12-11-2021, 06:48 PM
So as I now understand it, your oscillator frequency is correct at 600 kc, 25 kc high at 760, 40 kc high at 950 and 50 kc high at 1200 kc.
With this further info and the fact you checked and aligned your IF at 470 kc again, looks like the IF is not at fault since the tracking offset is not constant but varies from 0 to 50 kc.
This points to an oscillator error as you tune higher in frequency. The tuning capacitance is too low as you go higher in frequency. Check the connections to the main tuning cap as each section has a split stator where both stators are used in parallel on the broadcast band.
Could still be caused by the AFC circuit since the 6N7 control tube is always in circuit even if you short out the AFC with the switch. I would double check any work you did in the oscillator and AFC sections of the RF section.
With this further info and the fact you checked and aligned your IF at 470 kc again, looks like the IF is not at fault since the tracking offset is not constant but varies from 0 to 50 kc.
This points to an oscillator error as you tune higher in frequency. The tuning capacitance is too low as you go higher in frequency. Check the connections to the main tuning cap as each section has a split stator where both stators are used in parallel on the broadcast band.
Could still be caused by the AFC circuit since the 6N7 control tube is always in circuit even if you short out the AFC with the switch. I would double check any work you did in the oscillator and AFC sections of the RF section.
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