[ARC5] Re: [Milsurplus] History of Ham Mods: Opinions?

[Mike Hanz]

Thomas Adams wrote:

> At 08:52 AM 6/15/2009, David Stinson wrote:
>
>> Should a collector's guide to WWII radios, which emphasizes the 
>> history of the equipment,
>> include a section citing examples of exceptional ham radio mods?  On 
>> one hand- it is a part of the history of these sets.  On the other; 
>> such a citation might encourage
>> further destruction of what are now historic pieces.
>> Your Opinion?
>
> */First off...  I start to get uneasy whenever somebody starts talking 
> about "Collector's Guides" for ANYTHING.
> /*


While I'm sympathetic to your unease, as far as I'm concerned it really 
depends greatly on the definition and purpose of the guide.  I've never 
been much on what a person decides to name something, as long as the 
product is useful for me.  For example, Michael Tauson's wonderful 
little booklet "A Users Guide to Aircraft Radio Corporation Receivers" 
has been an active reference for me for years, and one could easily 
ascribe a "Collector's Guide" definition to it.

> */There's a thread going on right now about the BC-1031 panoramic 
> adaptor. /*


Could you share the group that is discussing it?  I might have one or 
two inputs....heh.

> */Did you know that there was a BC-1031 aboard the ENOLA GAY when she 
> left Tinian, bound for Hiroshima?
> /*


No, I didn't know that, Tom.   :-D   It surprises me just slightly, 
since I have spent many hours getting the equipment list correct for all 
the countermeasures equipment I donated and actually installed in the 
Enola Gay.  The BC-1031 (and BC-1032) were used in USAAC/USAAF aircraft 
for a very limited time - primarily in the desperate year of 1942 after 
the war started - entirely because they were the only Signal Corps 
panadapters available that could do the job at the time.  See 
http://aafradio.org/flightdeck/early.htm for a more elaborate 
explanation.  They were impossibly heavy, the physical envelope didn't 
conform to the ATC aircraft rack standard, and required two separate 
units to interface the two Hallicrafters sets that were the lower 
frequency mainstays for the early countermeasures tasks.  Early in 1942 
it became apparent that military grade aircraft countermeasures gear was 
going to be essential, and a number of programs were started to 
design/adapt equipment for this role.  The vastly superior AN/APA-10 was 
the initial panadapter product of this effort, covering three different 
IF frequencies by a simple switch setting (though to be truthful the 
30MHz IF had to be manually swept.)  That allowed it to serve an 
AN/ARR-5 (repackaged Hallicrafters S-27/S-36), AN/ARR-7 (repackaged 
Hallicrafters SX-28, with -A improvements), and APR-1/4 series of 
surveillance receivers.  If you want a solid, documented list of what 
was on the Enola Gay on 6 August 1945, see 
http://aafradio.org/NASM/Flight_report_Aug-6-1945.jpg - the RCM (Radio 
Counter-Measures) equipment is listed in a separate line.

> */It was there because it was necessary to know prior to the drop if 
> Japanese radio or RADAR operations could interfere with the RADAR 
> altitude trigger aboard "Little Boy"...   which was, believe it or 
> not, a modified APS-13 "Tail End Charlie"  RADAR set, used in the P-51 
> Mustang to cover it's ass in the event that a Messerschmidt  slipped 
> in behind without the pilot noticing.
> /*


To elaborate, there were four of the APS-13s in each weapon, in both 
Little Boy and Fat Man - all having a different set of frequencies to 
avoid interference.. There was an averaging system to account for spin 
of the bomb casing in flight. The weaponeer could have switch selected 
an alternate set of frequencies if Jacob Beser (the RCM officer) had 
identified potential interference.

> */WHERE DID WE GET THIS IDEA THAT WE'RE MUSEUM CURATORS???
> /*


Don't know that we did...everyone has a different view of things, and I 
never try to ascribe my personal motivations/values to anyone 
else...they're mine alone.  Have a cool 807 and relax...nothing in this 
hobby is worth getting all hot and bothered about.

73,

Mike de KC4TOS