[ARC5] Items of Interest

[Robert Eleazer]

First, relative to the SCR-274-N and ARC-5's outstanding characteristics, being a pilot, amateur aviation historian (although I have been paid for my work) and not much of a EE, I like to think of them in the context of their intended use.

The "modular" design of the Command Sets was simply brilliant from the WWII communications standpoint.  Rather than having a fighter pilot cranking away, switching coils, and tuning - or being stuck with just one channel - all he had to do was punch a button and talk.  Given the typical 3 receiver and two transmitter setup used by the USAAF, the only tuning the pilot likely had to do was of the BC-453 to tune in control towers and navigational beacons. The 3-6 MHZ and 6-9.1 MHZ receivers he had no reason to touch and it is a bit astonishing that they even gave him the capability to do so.  He talked to control towers with the HF sets and listened to them on the 190-550 KHZ band.  This is further illustrated by the fact that aircraft bound for certain theaters, such as the P-51A going to the CBI, had an additional extra transmitter shipped with the airplane for use in local conditions; this came in handy when the USAAF aircraft in Burma proved to be the only ones capable of talking to the ground troops for CAS - the first such use in the war.

The ARC-5 setup of the later F6F and F4U, which mixed the HF and VHF ARC-5 sets is especially brilliant, giving fighter aircraft both kinds of capabilities, and with the capability to reinstall the 190-550 capability for stateside use.  I think it was at least 20 years before that kind of capability was reintroduced into fighters.

And of course, the ARC-5 "modularity" was especially kind to the maintenance guys, who could always yank a balky set and stick a new one in very quickly.

Second, about building a QRP set into a military case, as we saw last weekend, Mike Bittner, W6MAB has done THE superb example of that, all made from scratch, no raping and pillaging of venerated objects required.

Third, while troubleshooting a DX-150A I found a schematic from Ham Radio magazine on building a solid state VFO using ARC-5 transmitter tuning components.  This is a much more sophisticated circuit than using the FET in the tube socket we discussed some time back.  I will scan the schematic and provide it on request.  And the DX-150A is still broke.

Fourth, I have come into possession of a RU-16 Coil Set Container, Type CW-47029, Range K, Western Electric, Contract Date 21 April 1941.  It is in excellent shape, the Wrinkle/Krinkle finish almost entirely intact.  I acquired it at a cost of about $13.00 solely because I thought one of y'all might want it.  Photos on request.

Fifth, speaking of Wrinkle/Krinkle finish, repainting of my BC-348-J is not going well, not at all.  I was about to give up and just use the 2nd paint job, and then I spied a Heathkit SG-6 that I had painted Wrinkle/Krinkle last year and had thought it turned out terrible - the spray can leaked all over me and everything else in range - but it still looks much better than the 348!  I took a 40 mile round trip today, just looking in stores for what I think might work, and not finding it.  3rd paint job coming up....  David, you were right!

Wayne 
WB5WSV