[Milsurplus] Philippine Guerilla Radio

[Hue Miller]

> Hugh
>
> The nearest transceiver fitting that description could the navy MBM one
> introduced in 1941.
> Wireless for the Warrior Volume 4(Clandestine Radio).
> It seems that it is the Navy version (equivalent) to the Army PRC1 or 
> PRC5.
> It had everything that you describe below, a wet 6V battery, vibrator P.S.
> The receiver and transmitter were housed in two water proof suitcases
> resembling
> luggage.
> Power output varies between 6.5 to 20W depending on frequency.
> Andre

Yes, that is the only one that came to mind. I was puzzled by the author
describing it as so low output as to be unusable, besides that the suitcase
design in no way disguised or hid the radio. Instead, author states carrying
one of those suitcases was like a sign saying "Nab me - I'm a spy".
He described the output as being only a watt or two. I think, one, the 
author
does not remember perfectly, some radio he only saw a few times 50
years ago. Two, I don't think there was sufficient training on the radio.
The output circuit is a L type network with a variable capacitor from PA
plate to ground, and a roller coil from the plate to the antenna
connection. I think it would be easy to tune up on a higher harmonic
instead of the right frequency. Three, maybe the charger was too weak,
as the author says, and the built-in wetcell never charged up well.  I
think  it must have been a problem with the tuning, as there also was
a handcrank generator supplied with the radio. After the first radio
was discarded in Manila bay, the rest of the supply were disabled,
renedered unusable, and then set up in their camps, the idea was
that if they had to flee in a hurry, they would take the "real" radio
that they used, and leave the disabled one to make the Japanese
think they had captured the radio, and not look around any more,
where the actually used radio might be hidden in the jungle.
But I think it was a training issue. And maybe Jefferson-Travis,
who built the MBM, ( if it really was the MBM ), should have used
instead a more conventional output circuit like the PRC-1, PRC-5,
and TRC-10. Just occurred to me that the TBX uses the same
kind of antenna tune circuit as the MBM. Is the TBX easy to tune
up on harmonics? Or is there a minimum tap position on the TBX
coil - unlike a roller coil - so you have a minimum inductance,
which limits the upper harmonics you could tune to? Opinion?
Oh yes - one more item - the MBM has only an antenna current
meter - no plate current meter.
BTW, I wondered why BC-474s weren't procured for this role.
Certainly that radio would have been better than the ATR-4.
I suspect, maybe no more were unissued in stock, and maybe
impossible to take back the ones in USA already issued to
various training units. Then the usual Army bureaucracy
and inefficiency - Stahl describes how long he had to beg
for airdrops of weapons and supplies. Maybe the Navy
would have done a better job, been better organized - and
they would have used a better radio too, which they had
plenty of - the TBX.  -Hue