[ARC5] [Milsurplus] My "ARC-5" Impressions (long)

[Kludge]

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net
[mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Mike Morrow
> I think we may have some differing opinions on details, but not in our
> admiration of these sets.  But...

That magic word ... 

> I think what is impressive about the A.R.C. effort was how quickly the
> 1938 state-of-the-art Type K designs became woefully obsolete in less
> than seven years.  

Huh?  The war ended seven years later and, as you mentioned, the shift to
VHF and later UHF had begun by that time.  Pretty much everything we went
into the war with, including the SCR-522, was "woefully obsolete" by war's
end.  So why single out ARC unless that "admiration" is rather tainted by
personal prejudices?

> The AN/ARC-5 is arguably the ultimate MF/HF command set,
> yet it was arguably obsolete less than a year after introduction, replaced
> where possible by the VHF-AM and later UHF-AM command sets that have
> dominated since late WWII.  

The HF AN/ARC-5 went on to serve in Viet Nam.  My Dzus fastened copy of a
C-40 was designed to control one each (tunable) R-26, T-19 or -20 and T-23
along with one each Type 12 R-11 and R-19.  (One could hope that the T-23
had been replaced with a T-126 but who knows.)  There is also provisions for
an FM rig which would have been a BC-1335 with the original installations
but with this later edition may well have been an AN/ARC-44/-45 combination
FM and UHF AM setup.  In any case, it's a rather unique 2 Tx, 3 Rx
arrangement.

> Sure there was a lot of HF command set use,
> but it seems hard to justify that use from a performance standpoint.  

Why?  We went into the war with it so there was an established base and,
while the AAF in the ETO was forced into using VHF due to operating out of
fields in England which were already so equipped, that was not the case
elsewhere.  It's interesting to note that many of the heavies (bombers)
there also carried HF command equipment which dilutes that whole VHF Was
King concept.  Even better, some of the English airfields had HF command
equipment in the towers along side the VHF equipment.  

> I know I also have an unpopular opinion about A.R.C.'s VHF technology.  

Very.  Oh, and a wrong one too.

> I know of no other way to characterize A.R.C. VHF developments except as
an
> almost complete and unproductive failure, especially when compared to the
> output of Western Electric with the VHF AN/ARC-5 and AN/ARC-1, and
Colonial
> with the AN/ARC-3.  

The BC-950 and later T-23/ARC-5 along with their companion receivers were
trash designed as replacements for the SCR-522 that would fit existing
SCR-274-N mounts.  It failed miserably and the AAF kept the SCR-522 instead.
The Navy had use for some, among other things as a replacement for the even
worse WE 233, so had WE convert them to fit the AN/ARC-5 system.  I agree
that the AN/ARC-1 and -12 were superior equipment but after WE had gotten
spanked twice already they had to do something.  However, the AN/ARC-1 and
-12 were 1.) later products, and 2.) designed *after* crystals became
available in quantity again.  (Interestingly enough, the AN/ARC-3 family was
vastly superior to the WE products and was designed & built by a company far
smaller with far less VHF design experience.)  

The ARC VHF equipment wasn't a failure so much as being designed at the
wrong time.  Had crystals not become available again in quantity, the
situation would have been quite different and it would have been the VHF
radio of choice for the AN/ARC-5 racks.  As in so many things, timing is
everything.

> A.R.C.'s VHF products are very much in a blind alley,
> and even their post-WWII VHF gear like the Type 12 was certainly
second-string
> or worse to what other manufacturers were producing.  

Let's see ... The Type 11 (T-11, R-11) was released 1 July 1946.  Type 17
(T-11, R-15) came about a year later in mid 1947 and the Type 15 (R-13 which
was essentially a repurposed R-15) came out at roughly the same time along
with the Type 18, a stand alone T-11 intended to be used with a receiver
other than an R-11 or R-15.  It went well with the Type 15 which covered up
to 135 MC at the time.  The R-19 and T-13 appeared for military use in place
of the T-11 and R-15 roughly the same time or shortly after along with the
R-10.  (The R-22 followed along as a replacement for the R-10 although I've
never seen one.)  

We'll ignore the rest of the line and stick with this core for the moment.
The postwar private aviation boom ARC and others expected never happened but
those who were flying got their airplanes' radios upgraded or kick started
with this equipment since it was pretty much "first out the door".  The
military liked it and bought it as COTS equipment to put in their lighter
aircraft where they continued using it through the Viet Nam war.  Through,
not up to.  It remained in civilian use as well although sales to civilians
was restricted in or slightly before 1960 for most of the transmitters.  Of
them, most weren't available to civilians anyway, specifically the T-13,
T-20 and T-23 which covered 125-148 MC and TV-10 UHF transverter.  The T-11
and T-21 (a 10 channel version of the T-11) were dropped from civilian sales
by 1960 but continued to be available for military purchase.  The T-22
(essentially a 20 channel T-11) remained available as did the "second
generation"* T-25.  The R-15 had disappeared by 1960 but the R-19 and R-20
(single light marker beacon Rx) were still being sold.

* The "second generation" equipment is generally anything that goes in the
ARINC racks like the T-25, the Type 21 ADF and the Type 210 (RT-11) with the
later Type 15 with the R-34 receiver a half step since it's basically the
older version modified.  This equipment is typified by using more submini
tubes and/or crystal synthesis for frequency control.  While it is
definitely newer designs, its Type 12 heritage is pretty clear when one digs
into the innards.  Anyway, this isn't any kind of official designation, jut
a method I use to help keep the original Type 12 equipment separate from the
later equipment in my mind.

With all that fancy new equipment that was available (The Narco Mk 12 hit
the market in the 1960s, for example), why did the military prefer the ARC
equipment over the "better" stuff for as long as they did?  Why did
civilians continue to use it at least into the late 1960s when I saw it in
use in various aircraft I worked on?  This is original Type 12, not the
later equipment although there was plenty of it as well.  For that matter,
why did the 2nd generation FES-1240 I have that was installed in a privately
owned 1960 Cessna 310 not get removed until 1996 in anticipation of the 1
January, 1997, cutoff due to a change in FAA regulations regarding frequency
stability due to the new 25 KC channel spacing?  (The list of radios that
lost their type certificates on that date is long with ARC & Cessna
equipment only a small part of it.)  

> (The RT-11A, part of the
> A.R.C. Type 210 commercial VHF set, is a neat and no doubt very expensive
set
> from more than 15 years after WW II's end.)

The RT-11 was the Type 210, not just part of it.  It also made its first
appearance inside that 15 year span, not over it.  And finally, it wasn't
commercial equipment any more than the Type 12 was.  It was quality
equipment that commanded a price to match but ARC had an established
reputation for building quality radios.  Ask anyone who worked on them, one
of whom is on this and other lists.  

> There was little MF and no HF command set legacy in the post-WWII A.R.C.
> designs, except for the oddball AN/ARC-39 and the AN/ARN-59.  There were
only
> the simplified R-10A BCB and R-11A beacon band receivers, and only R-13,
-15,
> and -19 modifications of the failed R-112 and R-113 VHF designs.

I have to admit the AN/ARC-39 is a curious piece but even with the small
quantities in which they were built (sloppy sentence structure but I'm still
on my 1st liter of coffee.) they are evidence HF command equipment still had
a place in military planning.  The AN/ARN-59 (ARC Type 21) was a top quality
ADF and had nothing to do with any command structure.  The R-13, -15, and
-19 weren't extensions of anything "failed", just not utilized due to
changing circumstances.  Again, your prejudices are showing.  As a note, the
R-13 was replaced with the R-34 which, even though it's range was reduced,
was still able to be mated to a T-11 et al for comm use as well as nav and
the R-15 was dropped due to being redundant.  

> In spite of what I've written above, I admire the beauty and execution of
> the engineering shown in the ultimate Type K, the AN/ARC-5.  It's
undeniable,
> and a real joy to see.  

Could have fooled me.

> I suppose if I were to identify an operational defect in the design of the
> Type K sets, it would be the great difficulty of netting an easily upset
> coffee-grinder receiver to the associated transmitter.  

This is a carry over from previous equipment like the SCR-A*-183/-283.  To
me, the ideal solution would have been a dial lock or at least a brake to
discourage dial twiddling etc.  Having flown with coffee grinder radios (ARC
and others), I can say from personal experience that simple vibration is
enough to cause some of them to slip off frequency.  One of the worst was
the Narco Superhomer while the ARC radios were the least prone to do so.

> That would have been especially valuable for the
> ARA/ATA and SCR-274-N sets, for which there are pilot memoirs bemoaning
the use
> of coffee-grinder command sets, 

If they hadn't twisted the cranks so much, they wouldn't have had such a
problem.  Not getting an immediate response to a call lead them to figure
the radios had drifted so they started twisting away not taking into account
the idea that the other folks had problems of their own (Getting shot at
comes to mind.) and weren't in any position to respond.  Sooo ... it was the
radio's fault.  

> The stabilized and locked-tuned MF/HF AN/ARC-5 receivers would have
overcome
> this netting problem somewhat.

It took the crank away from the guys in the cockpit is what it did.  A
signal source was required to set up the radios just like before but the
pilots couldn't do anything to "detune" the receivers anymore.  

In talking with an ex-list member a couple years ago, one major flaw in the
Type K design was pointed out to me, that being the ergonomics of the
control boxes.  The Model D boxes were designed with the idea that a pilot
wearing flying gloves would be using them and had nice "man-sized" switch
handles.  The Type K boxes, by comparison, had dinky little ones that were
not designed with the idea of flight gloves being worn.  In an effort to
cram more great tomatoes in that little bitty can, they messed up that part.


Best regards,
 
Michael, WH7HG ex-K3MXO, ex-KN3MXO, WPE3ARS, BL01xh ex-Mensa A&P PP BGI 
I am me.  I’m the only one who’s qualified.
http://www.nationalmssociety.org/chapters/NTH/index.aspx
http://wh7hg.blogspot.com/
http://kludges-other-blog.blogspot.com
Hiki Nô!