Hi gang, I have some RACAL RA6790 crystal filters availale. Type 8411 400 hz Type 8412 1.2 khz Type 8413 3.24 khz I would like to swap them for Type 8409 3.24 khz LSB Type 8410 3.24 khz USB Type 8414 6.8 khz 73 Ray vk2ilv/vk2no