[AMPS] 4CX-800s vs 4CX1600s

[George T. Daughters]

On 27 Nov 00, at 8:08, Bob Marston wrote:

< snip >

> The 4CX-1600B with the exception of the Austrailian Emtron design has not
> seen it's way into commercial designs because Svetlana can not provide a
> reliable deliver schedule for the tube. 

Ten-Tec and QRO now offer amps based on the 4cx1600b.  
Svetlana has, indeed, had difficulty with delivery.  Maybe that's 
fixed now.  I don't know.

> George Daughters has built a
> homebrew amp around this tube and his intial reports were good. He hasn't
> said anything about how the amp has held up in ongoing service.

Here's an update.  The "Sunnyvale/St. Petersburg Kilowatt +" is 
still going strong.  It's been very reliable.  I tend NOT to run it with 
all controls fully clockwise.  I probably average about 1300W out, 
and it doesn't get more than warm.  I like cooooool components.

I've fiddled a bit with electronic bias switching to minimize heat 
generation during zero signal conditions.  I don't use it, because 
I've gotten comments like "It sounds like you're using heavy digital 
processing on your audio" and "You're not splattering, but your 
voice sounds unnatural."  My decision not to use it is just an 
individual preference, not a condemnation of the technique.  (The 
amp runs cool enough without it.) 

The amp is used heavily in most SSB and CW contests, so it gets 
more-than-average use. I've been using the same tube since I wrote 
the article.  

vy 73,

George T. Daughters, K6GT

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