[Milsurplus] Miniature tubes, clandestine radio

[Hue Miller]

> Any of these sets or "spy rigs" I have encountered use octal or hearing
> aid tubes, and all I can recall are indirectly heated .  Because the 7
> pin miniature was so new,  it might have been smarter to use tubes that
> could be found more easily in enemy territory in case the radio was
> damaged.   Another  question arises- how popular were small ( lunchbox
> or coat pocket) battery portables outside of the USA in 1940?  Because
> of enemy occupation and other regulations,  they might have been very
> rare.
>
>     Bruce Gentry KA2IVY

Add to the list, Navy CMS ( "looks like a spy type radio" but no one knows 
for
sure, apparently ) and the "Briefcase Radio" articled in a WW2 Radio News,
of which the only known example is  owned by Keith Melton.
Since the 7 pin mini was new, and incomplete in 6 volt tubes, the choice was
between octal or loktal and the 1-volt miniature octals or 7-pin minis.  For
radios such as PRC-1, PRC-5,TRC-10, and MBM, I would guess the choice of
the larger 6 volt tube was that, it was easier to power such tubes off DC 
than
it was to power the 1 volt filamentary type tubes from AC source - it 
requiring
a well filtered low DC supply when operating the latter from AC mains. Just 
my
guess.

Now re battery portables. European life was much more lean with less and
smaller everything.  Portable radio ownership among the public seems to have
been much less common there than in the USA. Interestingly though it seems
the German Wehrmacht ( Defense Forces, a very offense oriented 
establishment )
had more portable troop morale type radios than did the USA, surely in 
different
types and I suspect also in pure overall numbers.  I asked my father about 
radio
listening for news in his units - he said he never saw a portable radio - 
that news
was gotten from attached radio communication groups who tuned their 
equipment
to BBC at night for news. I am not saying his unit was the rule but 
certainly it seems
there were plenty of battalions where a privately owned or even army issue 
morale
radio was just not seen. I have seen 6 different types of Wehrmacht troop 
morale
receivers and I believe there were at least a few more. I recall readiing in 
one war
account, German troops were moving forward, expecting to merely invest an
unoccupied village, some of the soldiers carrying portable radios which were 
heard
playing. Unfortunately for them a US tank force had already set up in the 
village and
annihilated the approaching Germans.  The proceeding just to comment on use
of portable type radios. Germany did not yet have miniature tubes AFAIK 
outside of
acorns.  -Hue Miller