[Milsurplus] I stand corrected

[Ray Fantini]

The SCR-522 was a groundbreaking box when first interduced, I always thought the US SCR-522 was a copy of the British set but cannot confirm.  Speculation: Somewhere I read about how the British during the Battle of Britain monitored the HF radio channels used by the Luftwaffe and would gain an idea of units spinning up at their bases by listening to the HF traffic while ground crews were getting the radios ready prior to a mission.
In pure scientific and syops operations the Brits did it better than anyone. Knowing this they produced a low power VHF transceiver that would be almost impossible to receive at a distance but was ideal for air to air and short-range air to ground communications. Remember that these were the same people who had learned about the German low VHF signals used for blind bombing and successfully transmit alternate signals to miss direct the attacking squadrons.
Migrating air to air communications from the old American idea of low power HF AM to lower power VHF AM was genius.
The SCR-522 had a mechanical auto channel mechanism that was a nightmare from a maintenance standpoint but from the aircrew’s point of view the ability to have preset channels at the push of a button was decade’s ahead of the US concept of multiple radios that only supported a signal channel. The radio part of the 522 also had the disadvantage of being first that by later in the war far superior sets were being rolled out like the ARC-1 and later the ARC-3, they were more sensitive, had more channels and were less prone to fail in operation like the 522
Imagine a bunch of people will get offended by me saying the 522 was obsolete before the end of the war and how they had one and how wonderful it was but I had the worked on a couple and the LO multiplier stage was a dog that unless you had a strong crystal with tons of overtone outputs would result in poor sensitivity and a front end that had so much noise unless you had a strong signal, twenty to thirty microvolt you would just hear noise.
The ARC-1 and later ARC-3 were so successful that they stayed in service long after WW2 with the ARC-3 staying in service into the seventies. The SCR-522 was dumped in mass right at the end of WW2, that’s why so many Hams had them.
As to installations of SCR-522 in the B-17, I assume that was because the Brits had already established a robust ground to air and air to air command and control system so when the eighth set up business it was essential to have lesion on VHF also in the ETO in the bad old days of AM HF communications there were only a finite set of AM channels available so making use of VHF had that benefit, somewhere I think I saw something about how during Overlord that every AM voice channel was required to coordinate ongoing operations.
More Trivia! I am probably wrong but my limited understanding of US Military ground to Air coordination in WW2 consisted of special ground crews usually with at least one pilot attached that used a centralized forward location to talk to the aircraft. Going to assume support missions were requested by telephone or ground radio links and then coordinated and relayed to the aircraft, nothing like in the moves where our hero talks directly to the P-47 overhead on his 611
Its still an issue today coordinating air and ground ops and requires a forward air controller with a special radio to do.
There you go, more to discuss and argue over! And ample opportunity to prove me wrong.

Ray F/KA3EKH




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Subject: [Milsurplus] I stand corrected

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I don't know where I got the info on the Germans using FM and I am checking my books on the subject including the Signal Corp volumes that analyzes everything comm related from before the war until after.  But the Germans did have a coordinated set up, where troops on the ground could talk to an aircraft or tank to direct fire without having the request go to the rear to be relayed, one of the things pointed out as something to be corrected for the US  in the Signal Corp books. A little known fact was that just prior to the war,  the Army studied ARRL procedures and ham ops in action to learn how to relay a message from one point to another, being amazed at how fast and accurate hams were doing it from coast to coast.   I have a complete SCR22 station for the B17F that I have yet to restore, it is a Canadian made copy of the British TR version and to be honest, I have not messed with it at all and just judged from my misinformation I had about it, it was a total British invention with no massive modulator tubes like the 375, it was FM.   Plus it was a popular unit to put on ham band VHF, I think modified for FM.    Guess the real issue was Brit communications on VHF vs all the US on HF in the B17 and others .  I had one contact with a Brit Lancaster radio op from the era that said they had some Lancasters with BC375's installed.  On the B17 crew members could talk over the BC375 and listen to the BC348 selected  by  their individual control box at their station set to 'Liason'  if they had too, but only pilot and copilot could use the Command Set.  A couple WW II radio ops in contact with our B17F project  said they did not do a lot on the BC375 voice wise, mostly CW but rarely to never in a mission, just when they were in non-combat mode.  Even though they carried all the TU's, the TX was set up before a mission, they did not arbitrarily swap out a TU for another band.  There was a red faced TU that had a goniometer in it and was used as a comm jammer, but a rare unit today.  I have only seen one picture of that one.

Charlie in NC
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