[Milsurplus] more tube stuff!

[Mike Morrow]

Ray Fantini wrote:

>As long as we are on the subject of tubes, the R-392 has no high
>voltage or at least in a sense that I understand B+ in vacuum tube
>radios.  The 24 volt input is used to feed all the plate and screen 
>circuits. 

So did the receiver section of the Collin 18S HF transceiver (a.k.a. RT-380/AR, p/o AN/ARC-59).   The R-101/ARN-6 ADF did likewise.

>...ls their any other military radio, with the exception of those
> strange little WW2 LF beacon receivers that used the same trick?

Those beacon receivers would be the BC-1206-series, and the similar set known as the R-76/ARR-13 (had a button used to select 278 kc tower frequency directly).

Plus, many of the 75 mc marker beacon receivers like the BC-1333 and later models used a 28 vdc plate supply.  The historically important 333 mcs ILS glide slope receiver sets of the AN/ARN-5 series did too, though the 109 mc ILS localizer receiver associated with the AN/ARN-5 glide slope unit (BC-733 of RC-103) used a dynamotor HV supply.

I'm sure there must be several other mil sets from WWII and later that employed LV as a plate supply.

On the civilian front, I'm sure most of us remember the mid 1950s to early 1960s AM car radios that used "space charge" tubes (12AD6, 12AE6, 12AF6, 12EK6, 12K5, etc.) designed to function well with a 12 vdc plate supply (those tubes had a 30 vdc max rating).  I got one from a salvage yard 35 years ago that is one of the best AM radios I've ever owned (I love those Conelrad marks on the dial).  All the original tubes are still functional!

73,
Mike / KK5F