I just got two "classic" monitor receivers at the close of a radio swap. 1970's vintage receivers. A really great price. They were originally for monitoring VHF FM hi-band, I want to change them to monitor our local repeater at 146.640. Somebody had started the frequency change, but the crystal frequencies make no sense to me, because it appears that the first IF is not 10.7 Mhz, and no clue about the second IF either. My internet search brings up no tech information about the IF frequencies,, just a lot of ebay listings. so does anybody have actual information about the IFs or the crystal formulas??