[AMPS] NCL-2000 comments

Rich Measures measures@vc.net
Wed, 30 Dec 1998 15:02:46 -0800


Carl Heuther  wrote:
>................
>The NCL screen supply is no better or worse than the competition of the
>era. 
>
Rich Measures  wrote:
The NCL-2000 screen supply is capable of producing high current.   There 
seems to be  nothing to limit screen current.  

>>....... As I recall,  RCA recommends a rf-nfb R in an unbypassed cathode, 
>>like Eimac recommends for the 4cx600, like Svetlana recommends for the 
>>4cx1600.  The NCL-2000 did not.  
>
>
>The NCL strictly followed RCA recommendations right down the line. 

€  The cathode pins are grounded on the NCL-2000's diagram.  

>The cathode resistor is suggested as an option in Class AB1 and at 2000V or
>less ONLY.
>
>I tried ur QST mod many years ago ( 198 something)  and it brought the
>amp up into parasitic land. 

€  A lower vhf-Q, vhf parasitic suppressor -- i.e., one with better vhf 
damping ability --  caused the amplifier to oscillate at vhf?
>...........


Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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