[Milsurplus] chirpy xmtrs, Philippine guerrillas

[Mike Morrow]

Hue wrote:

>No- definitely not TCS ! The army had portable sets that were suited to
>this role. For example, the "Merrill's Marauders" group operating in
>Burma, often behind enemy lines, used the Army BC-654 set.  The
>BC-654 and BC-474 operated from handcranked generators (except
>for receiver section).   Also, they were easy to pack up and move
>away fast, if needed. 

Yes, I'd agree that the TCS would be very unlikely.

What about the Australian-made A.W.A. Type 1J50061 set that wade made for the U.S. Signal Corps as the "AMC-145" set after 1942?  This set looks identical to the classic Australian Coastwatcher set (Model 3BZ) as pictured in Walter Lord's book "Lonely Vigil" about those folks, and is mentioned at the very interesting 3BZ website at http://www.qsl.net/vk2dym/radio/3BZa.htm .  There's a well intentioned but problematic 3BZ transmitter simulation that appears when when the RADIO button is clicked at http://www.ww2australia.gov.au/coastwatcher/index.html .  Unfortunately, the panel simulated appears to have a few ham-hacked modifications included.

The pictures of the individual units in the manual show name tags with "U.S. Signal Corps" plainly inscribed on the plate.  The title of the Australian-printed manual is "INSTALLATION, OPERATION AND MAINTENANCE OF U.S. SIGNAL CORPS AMC-145 INSTALLATION."  Why would the U.S. Army have been buying A.W.A. Coastwatcher sets anyway?

I don't think the AMC-145 would have been the best choice for portable operations on the run.  The transmitter and receiver weigh about 45 lbms each, with integral vibrator HT power supplies.  The set required a 12 vdc lead-acid battery with a tap for 6 vdc.  That would be a lot of weight to cart around, plus how would the batteries be charged?

The SCR-284 (BC-654) is also NOT a very light-weight set for guerrilla operations.  I think the total minimum set weight for portable operation would be more than twice that of the SCR-288.  It only covers 3.8 to 5.8 mcs. 

Though it's no assurance that it filled such a role, it looks to me like that cute little SCR-288 (BC-474) would surely have been the most attractive light-weight set for this type of service, of all the various sets that were available.  When used for Morse transmission, it would likely have been quite servicable.  It covers 2.5 to 6.3 mcs (almost twice the coverage of the SCR-284) and thus is capable of covering frequencies that would be usable day or night.

Mike / KK5F