[Milsurplus] SCR-194, 195 compared to National TRW, TRM

[Hubert Miller]

It happened that random redistribution brought two manuals of interest into my hands in the same time frame.
I mean, the SCR-194, 195 manual TM 11-238, 1942, and surely not the first manual for this 1938 radio, and this booklet,
'A PORTABLE TRANSCEIVER for ULTRA HIGH FREQUENCY OPERATION' by National Radio Company, Nov. 1934.  This latter
booklet covers the TRW and TRM. The latter radio looks approximately similar in format and size to the National SW-3
and the former radio, TRW, has it installed in a wood case with spaces for batteries and handset. If you're familiar with
the 'Forest Service' radios used in the Pacific Northwest in the late 1930s to postwar, the appearance is quite similar to
those.
What I want to comment on however is the similarity of these National portable radios to the BC-222, 322.
They use same tubes in same roles.
The National has freq range of about 55 - 65 MHz.
The National uses a handset, like BC-322, unlike BC-222.
The National uses a B voltage of only 90, compared to 135 for the Army radios.
The National does not use a separate battery voltage for the microphone. So only 3 voltage sources compared to 4 for the
Army sets.
The Army sets have switching done by 3 relay points. The Nationals used a 4PDT switch. The National has an
additional switch section to disconnect the microphone current on receive, instead of a microphone push button. There
is no sidetone on the Nationals; the earphone is disconnected on transmit.
The National uses a wire antenna, ¼ wave or odd multiple, or vertical dipole.
The Army radio has telescopic antenna, vehicle mast, or vertical half rhombic ( I think it's called that. )

It's interesting to me that apparently the Army hadn't first envisioned use of their radio in true manpack operation.
I read this in QST or some Signal Corps journal. The radio was to be set down and operated, but it soon enough dawned on
the users that they could use it while carrying.
Probably there are only 1 or  2 people interested in this topic but I thought I'd put it out there for them at least.
-Hue
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20180603/5543676f/attachment.html>