[Boatanchors] OA2 CURRENT

[Al Klase]

Hi Bill,

315v - 150v = 165v
Assuming two separate VR tubes each with it's own resistor:
165v / 4000w = 41.25ma.  by design  (Perhaps a little high for the VR 
tube itself, but it gets shared with the load.)
41.25ma x 2 = 82.5ma total.  (Pretty close, but I'd measure the actual 
voltage drop across the 0A2's.)

Al

Magoo wrote:
> I'm trying to troubleshoot what appears to be excessive current draw in a 
> P/S employing a pair of OA2s.  With all tubes out of the chassis, 
> approzimately 10ma is being drawn through the choke (in the ground lead) by 
> the bias supply.  When both OA2s are plugged in (with no other tubes 
> installed)  that current rises to about 90ma, and that seems excessive to 
> me.  Both tubes test OK.....but are they?
>
> B+ at source is 315 and each tube is fed through 4K; with no load I 
> calculate 7 ma for the idling current on each tube.  Is my logic flawed, or 
> am I dealing with a pair of tubes which test good but are actually bad?
>
> Bill VE3NH 
>
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-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/