These FSK converters connect to the IF of a receiver
URA-6 has two CV-57 converters (for 455kc IF) and a CM-14 diversity comparator
URA-7 has two CV-71 converters (for 50kc IF) and a CM-14 diversity comparator
They are big, heavy, connect to teletypes, and painted gray - what's not to love?
(photo thanks to W5JV)
