[Heathkit] RE: SB-200

[Kenneth G. Gordon]

On 26 Jul 2006 at 18:34, Cam and Juli Hedrick wrote:

> I have an SB-230 that I reworked into a SB-200 style.  My output is
> 620 watts keyed down.  Amprex 572B tubes in it and are great
> tubes....20 years old, but only 2 years use.  Meter 2500VDC and .520
> ma, hmmm, a nice amplifier saved.

OK. Thanks for the data. If we assume that your meter readings are 
absolutely correct (foolish assumption, but good enough for this 
discussion), i.e. we ignore meter and visual errors, then you are 
running it at 1300 watts input. 

At 620 watts output, that is 47% efficiency, which is right in the ball-park 
for these types of amps.

As I said, 800 to 900 watts output with the rig as designed by Heathkit 
is pretty difficult for me to accept.

They are a darned good little amp, but they aren't SuperMan either, and 
don't/can't violate the laws of physics.

Ken W7EKB