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Further fiddling with VA62 code
Just an update. Since the 30-50MHz RF-IF SIGNAL switch setting has AM modulated audio tones I was hoping to be able to get the VA62 to output an AM radio band RF signal but the PLL in my VA62 will not lock reliably below about 15MHz even by changing the programmable PLL loop gain. Although it can be persuaded to lock down to about 8MHz by repeatedly flipping the RF/IF level select switch I added. Here is the RF/IF Level switch functionality you get in all the RF-IF SIGNAL switch settings:
PROG CABLE CH2-73 RF and IF levels (mod gives CH42=25.5MHz +/-9.75MHz in .25MHz steps)
STD CABLE CH2-73 RF and IF levels (mod gives CH42=25.5MHz)
STD TV CH2-83 RF and IF levels
30-50 MHz IF level only (mod gives 1-99MHz circuit limited to about 8-99MHz on mine)
45.75MHz VIDEO IF RF and IF levels
39.75MHz TRAP IF level only
41.25MHz TRAP IF level only
47.25MHz TRAP IF level only
4.5MHz FM RF level only
Dave
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