[Milsurplus] R-174 Puzzlement

[Barry Hauser]

I dunno -- this has never happened before, so maybe somebody can 'splain it
to me.

Recently got an R-174, AN/GRR-5 -- not the first one, so I'm familiar with
them.  This was known to some as a "gas radio" -- originally intented as a
gen. coverage HF receiver to use for broadcast warnings of CBR attack.
Mostly Korean War vintage.  It's the one with the "duplex" arrangement --
receiver on top, ubiquitous, do-all power supply/speaker on the bottom, that
will run on 6, 12 and 24 vdc as well as 115 vac, when the wind's blowing the
right way.

Anyhow, usually when you get a new old radio with tubes, a few tubes will be
bad, or sub par.  This one came in batting zero -- uses 8 tubes, 7 of them
are 1.5 volt jobbies, like 1L4's, 1R5's, and a 1U5.  Also uses one 3V4 for
audio output.  All very clean, bright and shiny -- all 8 NG.  Most seemed to
have burnt out filaments, others shorted and the 3V4 was extremely weak.  I
took a chance and used spares on hand and a couple of "borrowed" tubes to
test it out.  Works, on DC, anyway on three of four bands, so far.

I've been through a lot of tube radios of various types and origins over the
past few years.  Never come across this.  Might be a couple or three bad,
some weak, but not nada.  Tell me -- how can it be zero for 8?  Might be
series filaments, if that's any clue. Power surge?

TV-7 manual lists most of these tubes as "do not tap" when checking for
shorts.  Do you think somebody tapped?  Or maybe (paranoia now) this rx was
used to park some pretty, but dead glassware?  Hmmmm?

Barry