[ARC5] 24V B+ supply for "command" receivers.

[WA5CAB at cs.com]

The only thing special about the tubes in the R-392/URR is their filament 
voltage rating.  R-808/GRC-14, the competitor to the R-392, uses common 6V 
and 12V filament tubes like the 6BE6 and 12AT7 in the common up until that 
time series/parallel hookup.

In a message dated 03/09/2013 23:25:00 PM Central Standard Time, 
brokenthumb at live.com writes: 
> I have read the responses to my questions with interest. None of them 
> have addressed my questions. I shall restate them.
> 
> The R392 uses a series of tubes designed to run at 24v on the filaments 
> and B+. However the tube spec sheets I have read all go out to at least 200v. 
> Question; will a tube designed for 24v B+ SAFELY run with B+ at 200v or 
> more? Question; if it does, then is this series of tubes really 6/12v tubes 
> "in drag" so to speak? Comment; obviously these tubes run on 24v B+ and run 
> very, very well. In my (not even close to humble) opinion, the R392 as an 
> SWL rig is very nearly the equal of the R390. Collins designed both and if 
> you lift the lids on both, they very nearly look the same except for size. 
> Oh, BTW if you compare the selectivity graphs of the 85kc IF of the '453/R23 
> with that of the 392 at 2kc, they are virtually identical. 6 gain stages 
> at 455kc will do that.
> 

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480