[Milsurplus] Re: [ARC5] SCR-274-N Transmitter Dial Accuracy

[Michael Tauson]

On Sun, Jul 6, 2008 at 4:46 AM, Mike Morrow <kk5f at earthlink.net> wrote:

> I'm not considering the SCR-274-N made by WE and others to be A.R.C. gear.

Okay, here's where our points of view differ.  I look at the design
source otherwise it gets confusing.  For example, Colonial built the
SCR-522, SCR-274-N and ARC-3 (and probably other equipment) under
subcontract so who gets credit for them?  A large number of AAF/USAF
aircraft equipped with an ARC-8 didn't have any Collins equipment
aboard since a goodly number of the T-47As were made by Stewart-Warner
(among others) yet I've never heard anyone call it anything but a
Collins transmitter.  The ARR-1s and ARR-2s I have on hand here are
split pretty evenly between WE and Zenith so are the latter WE or
Zenith equipment?  And then there's the R-390A with something like a
dozen contractors in the soup.

By calling it A.R.C. equipment built under contract by WE or S-C or
whomever, this resolves the problem rather neatly by identifying the
designer and the builder at the same time.  Since my book's only about
A.R.C., I could exclude everyone else but I have to bring in the
contractors to be fair which means WE will get their spot in the shade
next to the iced tea thingie.

> Once one removes the command set gear, what else did A.R.C. contribute?

Wasn't this enough?  Every combatant that flew as well as a fat number
of transports et al carried command equipment, whether it be HF or
VHF, which suggests that it was fairly necessary to the livelihoods of
the aircrews.  On the other hand, not all Navy and not that many USAAF
aircraft carried the ZB or ARR-1 or the later ARR-2, and the SCR-274-N
and ARC-5 VHF components weren't built in any huge quantities - 1000 &
20,000 respectively.  (I think Colonial did some of them too, but I
can't remember right off.)

As a sidenote, my T-23 was built on a BC-950 chassis, complete with
the hole for the 815(?) socket.

> The T-126 appears to have been made in very limited quantities compared to the T-23.

It was.  It was a case of too little too late.

> The AN/ARC-39 seems to have been made in very small quantities.

There were only 400 A.R.C.-built ones.  There was a follow-on order
(or maybe a separate contract) for around 1000 but A.R.C. was busy
getting bought so it went to Sunair who, in turn, produced what I
shall politely refer to as junk.  (Think: Lewyt Vacuum Cleaner Co on a
really, really bad day.)

Some, though not all, wound up in places like the P-3 where it was
parked next to an ARC-94 and something VHF/UHF-ish.  The ARC-2, on the
other hand, went with the ARC-38 (the AM version) in the P-2 and P-5.
They also had something VHF/UHF-ish.

> What part is played by A.R.C. type 12 components in your system?

The system is built around the A.R.C. Type 12 C-40 control head,
although mine's a Stratocon R-2001 which is functionally the same but
made for panel installation in 1960.  Its a fairly conventional 3
receiver (VHF, HF and LF/MF), 2 transmitter (VHF/HF) setup with the
R-28 and R-23A/ARC-5 replaced by an A.R.C. R-19 and R-11 respectively.
 There is also provision for an FM set ("like the SCR-619") but I
doubt that particular set would have still been operational in 1960.

It came out of the 1952 edition of AN 16-45-122 which is the manual
for the Type 12 equipment.  It's not in the 1956 edition which, given
when the control head was made, is interesting.  While I didn't want
to build a normal 3 Rx, 2 Tx, setup, this one appealed to me because
it's different.

The control head has a dial for the R-26 so that's why I selected 3105
KCs.  (Reflective thought: wasn't that changed to 3110 KCs later?)

> It's much longer than the R-23, which was found only in backwaters after the 1960s!

I suspect that the R-23 is still found in service anywhere we donated
or sold aircraft that were so equipped.  (Actually, I think that can
be expanded to a wide variety of electronics.)  The less fortunate
countries are more prone to use what works rather than look for the
latest & greatest.

Best regards,

Michael, WH7HG