[AMRadio] Filament voltage monitoring

John Lawson jpl15 at panix.com
Tue Feb 20 10:34:57 EST 2007

On Tue, 20 Feb 2007, Rick Brashear wrote:

> Gary,
> I sure do appreciate your advice and insight.  I agree completely about the 
> monitoring of the secondary instead of the primary filament voltage.  I have 
> no idea what GE was thinking other than to save a buck or two by using one 
> volt meter to set the filament on all the tubes instead of individual ones.

   The RCA BTA-1MX (And I would assume the others in the -1 series??) have 
a 220VAC meter marked "FILAMENT VOLTAGE" and it does read the 833 filament 
transformer primary, after the filament rheostat.  If it weren't for the 
re-wiring required, I'd be tempted to find a 0-15VAC meter with the same 
cosmetics and replace it.

   The other "gripe" I have about the -1MX metering is that the multimeter 
is small (3") and scaled 0-150% - which of course makes for a cheap meter 
- but the Operator now has no direct readout of the 15 or so different 
voltages it monitors...

   Oooohhhhh.... pooor babeeee.....     ;}



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