[Milsurplus] R-174 Puzzlement

[Bob Kulow]

>I've had a GRR-5 for a number of years.  Finallly got tired of the 
>vibrator buzz
>while using it on 120 volts AC.

>Rebuilt the power supply using one small transformer and silicon bridge 
>rectifiers
and eliminating most of the original parts.

>.
Ended up with the rcvr drawing about 10 watts from the AC line.  Also, it 
now weighs
about 1/3 of what it did.

Next step is to replace the speaker with one that sounds decent.

73
Bob WA2UEH
> >
> > 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
> >
> > _______________________________________________
> > Milsurplus mailing list
> > Milsurplus@mailman.qth.net
> > http://mailman.qth.net/mailman/listinfo/milsurplus
>
>_______________________________________________
>Milsurplus mailing list
>Milsurplus@mailman.qth.net
>http://mailman.qth.net/mailman/listinfo/milsurplus