11-14-2013, 09:18 PM
Honestly Chris, that variable cap doesn't look right to me. In general, the osc section needs less capacitance than the ant section, but in your case it looks extreme. No only are the plates smaller, but there are much less of them. The fact that you can't tune the LO below 1125 kHz seems to confirm there is too little resonating capacity available.
The only reason I can think of to remove the osc plates would be to bandspread the tuning so that the dial would cover a smaller tuning range. But this would also cause the tracking with the ant tuned circuit to be way off, which seems to also be what you are experiencing.
The only reason I can think of to remove the osc plates would be to bandspread the tuning so that the dial would cover a smaller tuning range. But this would also cause the tracking with the ant tuned circuit to be way off, which seems to also be what you are experiencing.