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

[David Stinson]

----- Original Message ----- 
>...  As they say "context is everything"....
>But your original comment about the "genius of the ARC-5" is 
>intriguing
>to me, at least.  As one who has spent a lot of time working with 
>them,
>what in your opinion are the most impressive or noteworthy aspects of
>the ARC-5 series design?....

Thanks for writing, Bob, and for bringing this up.
There's a lot to say, but I'll try to condense it down
to merely "huge."   :-D.

My admirations for the A.R.C Type "K" - derived equipment
are more anthropo-centric than technical,
though the tech certainly counts alot.

When speaking of the merits of the Type-K sets,
we do need to establish some context:
There are roughly three "eras" (chapters?)
to the "Aircraft Command Sets in WWII" story:

Pre-War 1932-1940:
Limited budgets and limited expectations, but great innovation.

Early War 1940-1944:
The era of rapid advancement and politicing for contracts.
Type-K is the climax of HF Command Sets for this era.

Late War 1944-1946:
VHF deployment gets serious,
but HF is still (and remains today) in service.
The great HF Command Set of this time is
unquestionably the ARC-2.

The Type-K story belongs in the "Early War" period.
Contrasting a Type-K set to those from a later period is
an invalid comparison, akin to setting a P-40 Warhawk
against an F-86 Saberjet.

Also, we need to remember the circumstances and missions
for which the sets were intended.
An HF Command Set was intended to provide reliable comm
from a pilot to other aircraft within a flight and to controllers.
Spare parts and logistics were not to be issues.
The set needed to be successfully supported and serviced
by young men with minimal experiance and training.

That said, the roots of my admiration are:

First- The Story.
I won't try to go into great detail here;
it would make a decent "Payton Place" novel.
A.R.C. was a graceful and "pricey" fish swimming
with big, hungry sharks and lumbering crocodiles.
Throughout these three periods there were competeing camps-
generals, admirals, Senators and every other cockeyed "cook"
sticking their stirring-spoon into the great big "pot"
of aircraft HF communication.
Crystal advocates, non-crystal advocates,
preachers singing the "Gospel of UK Radios,"
"prophets of Profit" and of Doom all creating a cacophony
of demands and counter-demands, and most of them with
enough "juice" to have caused any company serious trouble.
Even as late as Iwo Jima, you find after-action reports with
naval comm officers raving for/against VHF/HF crystal/non-crystal.
Out of this chaos, A.R.C. stuck to its chosen task of bringing
quality and surprising innovations in production
and support to their products.
Within their sphere, they were the "Apple" of their era.

Second- C-59 and Engineering Audacity.
If you look in the back of an early ATA or SCR-274N set,
you'll find an odd-looking critter named "C-59."
This little marvel is a hand-made capacitor, formed of sheets of
mica and conductor, stacked on a bolt for with a nut to "tweek"
the compression juuuust so to get the oscillator tracking right.
A.R.C. new it couldn't get the value or quality cap it needed to
make its design work correctly.  They could have whined and
gone for compromise.  Afterall; having to "hand-throw" custom
parts when you're looking at a contract for thousands of units
and with a "rush" deadline- that would be madness.
But that's just what these audacious engineers found a way to do.
And that great, mythical "bug-a-boo" of early MO-PA transmitters:
Drift, was all but eliminated as a real problem by A.R.C.'s
"ahead of its time" understanding of thermal dynamics
within their sets.   That bit of "coolness" needs its own post.
With these and other examples of pragmatic "can do,"
it's no surprise that A.R.C. produced the zenith of aircraft
Command Sets of the Pre- and Early War eras.

Third- Mission Mindfulness and Engineering Elegance.
The Type-K sets were built with the intended mission firmly
fixed in the engineer's minds.  Compared to anything else available
for the mission, they were easy to spare, easy to service
and easy to operate. They were more reliable and better-performing.
What makers like Bendix did with a leather gauntlet and a meat-axe,
A.R.C. did with a silk glove and a stiletto.
Assume you have an ARA receiver and and an ARB receiver on
your work bench.  Both have an open primary coil in the 2nd IF.
How long will it take you to fix them?
Open an ARC-5 transmitter and a TA-12 transmitter.
How many "single source, maker-only" spare parts will
you need to support the ARC?  For the Bendix?
How many mechanical failure modes can you count
in the ARC-5 vs. the TA-12?  How much training
and experiance will a Radio Mechanic need to competently
repair one vs. the other?

Forth:  The History.
>From 1939 to 1946, Mankind had a great and bloody discussion
with itself about just what kind of people we were going to be.
The tools our fathers and mothers used to settle that epic debate
deserve our study and our respect.

Fifth:  Personal Challenge.
It's easy to buy a "plastic radio" and work the world.
DXCC? Posh.... been done hundreds of times. Boooor-ing.
Work yet *another* low-orbit repeater satellite?  Yawn....
It's easy to trade money for a false sense of accomplishment.
I want something few- or no- other people will do.
I want some sweat in the game.   I want to fix on it
until my fingers bleed to make it work.  I want to look
at it and know I've actually DONE something besides
swipe a credit card and open a cardboard box.

And lastly...  Because it's so much FUN :-).

GL OM ES 73 DE Dave AB5S