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[AMPS] PA Recommendation Wanted

To: <amps@contesting.com>
Subject: [AMPS] PA Recommendation Wanted
From: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net)
Date: Mon, 9 Jun 1997 17:03:32 +0000
>If what you and Mr. Rauch profess is true, Ian, Eimac and Svetlana 
>should caution designers to use "stiff" grid bias supplies in Class 
>AB1 amplifiers.  However, they do not. 

Ahh. The same bent logic applied to neutralization rears its head 
again in a new topic. "If they DON'T mention something, it must NOT 
be true." 

>  If what you and Mr. Rauch say is true, Eimac erred by stating
>that up to100k of series R was acceptable for the 4cx15,000A.  
>Consider the spec. sheet for the 4CX35,000C.  Again, Eimac 
>recommends lim> (note:  the 4CX35,000C appears to be a serious 
>device.  2.9kW filament; anode rated at 20kV/15A.  This thing makes 
>X ays, folks!)

Eimac only says to NEVER allow the grid resistance to get over "X" 
ohms for some tubes. All that means to me is they are setting the 
upper limit for grid resistance. They don't say WHY.

If they wanted us to keep the resistance at the upper limit, 
they certainly would have printed something like this.....

 "NEVER let the grid resistance become less than 100k ohms".  Or 
perhaps they would say this......  "Always use a grid supply 
resistance near 100k ohms".

But Eimac didn't say that. They simply said "never exceed X 
ohms."

Your right on target Ian. Everything you say makes absolute sense.

73, Tom W8JI 

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