[MRCA] SCR-522 and variants VHF common denominator it ATC IN ETO

[MARK DORNEY]

More digging done. The SCR-522 is a common denominator in aircraft commo in the eto. Almost every USAAF aircraft carried one. The interesting thing about this transceiver is that there were variants that differed mostly in the power supply needed for the radio. The SCR-522 required a 28v dc power supply. One variant, the SCR-542 used the same BC-624 and BC-625 radio sets along with  rectifiers, and required a 14 volt power supply ( most WW2 US Army purpose built radio vehicles were 12 v. ) The SCR-624 also used the same BC-624 and BC-625 sets, used different rectifiers than the SCR-542 and required a 110 volt 60 Hz AC power supply ( supplied on the field using a PE-75 generator ). 

Established airfields, as part of their TO&E had the BC-639/BC-640 set, which operated on 100-156 MHz, so the need to rig up a radio to operate on 100-156 MHz would be minimal,  unless there was a problem with the the field’s main radio.  There are pictures of some SCR-522 pilot’s remotes mounted to a controller’s desk in the watch station. Could the BC-639/BC-640 use this remote?  The SCR-624 used EE-8 field telephones in their set to remote the radio using this pilot’s remote, which suggests that either the BC-639/ BC-640 could be wired to this remote, or an SCR-624 or a battery power supplied variant of the SCR-624 was being used in the watch station. 

It is interesting to know there is a variant of this aircraft radio that could be mounted and used in a ground vehicle to provide coms in very forward areas and very forward airfields. I’ve only heard of one other aircraft radio that could be operated out of a ground vehicle without major modification - I understand a GF-11/RU-16 was fitted to a US Marine gun carriage in the Pacific.   

The next question for HAMS is, can we put together an SRC-624 and operate one legally, and how difficult would it to find the components. Interesting 

Thoughts?

Mark D. 
WW2RDO

“In matters of style, float with the current. In matters of Principle, stand like a rock. “.   -   Thomas Jefferson 

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