Can anyone authoritatively tell me when the German armor began using 20-30 MC for their comm? I've been told this was late-war, that the earlier sets were MF or low HF. I ask because I have an early-war (pre--U.S. entrance) vet's account of airborne missions to "listen in" to German mechanized units as they moved into the low countries, using equipment that tuned from 13 to 35 MC. Thanks.