Hello all - I have a never-used TT #221 crystal filter (9 mHz, 250 kHz, centered on 500 Hz). Great for DXing. I would like a straight swap for a clean, good condition and working 6.3 mHz Ten-Tec #285, or # 288 filter. My #221 is in its original TT box and packing. If interested let me know. 73 - Don, VE1BN at aol.com