FOR SALE: Group of Three 3.5 MHz band U.S. Signal Corps BC610 crystals These are the large FT171-B crystals with a handle on the top, as used in the BC610 and T368 transmitters etc. 3510 KC 3580 KC 3870 KC Available for $19.00 each or will sell the group of three for $39.00 Shipping additional 73 - Brian, AF4K