Fw: SB-200 plate current

[Peter A Markavage]

You might want to read the article on the "SB-200 Balanced Grid Circuit"
in QST, August 1986, page 38 and a followup article in QST, December
1986, page 45.
Pete, WA2CWA

On Fri, 13 Jun 2003 17:30:39 -0500 Jeff Stewart <stewgoat at INDY.NET>
writes:
>    I just did a visual and a 33 ohm resister off the grid of one tube
> R21 or R22 is cracked in two.  The tube on that side has a
> discoloration on one side (the gitter appears to be at the bottom)
> so it may be toast.  Now to figure cause and effect I guess before I
> replace the resistor.
>
> Jeff
>
> ----- Original Message -----
> From: Jeff Stewart
> To: HEATH at LISTSERV.TEMPE.GOV
> Sent: Friday, June 13, 2003 2:51 PM
> Subject: SB-200 plate current
>
>
>       About what plate current max and minimum should I see
> depending on the age of the 572b's of course?  What's normal grid
> current also?
>     I know the manual says don't go over 500ma on the plate,  but I
> see only 200ma however the relative output on the amp shows about
> 600 watts on a dummy load.  Seems like the Plate current is onlly
> half what I should see.
>
> Thanks,
> Jeff
> http://www.qsl.net/ka9dad/

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