[Amps] 3cx400A7 and 8877

[TexasRF at aol.com]

Hi Paul, your understanding of the buck/boost windings is right on the  
money. Ameritron amplifiers have used this technique for years.
 
The voltage tripler idea seems less feasible considering the poor voltage  
regulation that comes with multiplying circuits. It might be useful to  
haywire a circuit for testing just for a quick answer.
 
The 8877 will work just fine on 2250 vdc and 1A plate current. With the  
usual 60% efficiency, it should give an output of about 1300 watts.
 
73,
Gerald K5GW
 
 
 
 
In a message dated 5/20/2011 9:54:59 P.M. Central Daylight Time,  
kg7hf at comcast.net writes:



Hey gang, 



I've got a new toy I'm wondering  your opinions.  



I got two new RF decks, one based on an  8877 and one based on a 8874.  
Unfortunately I don't have a power supply  for either one.  I do have a 
functional power supply for a 2 x  3cx800A7 amp.  It can deliver 2250 VDC @ 1.2 
amps. 



My ps  has 2 x 112.5 16 and 8 v primary windings to be used in combo for 
various  input voltages, for the 3cx800, the output 868 VAC dumps into a 
doubler to  produce the 2500 no load voltage. 



I was thinking for the 8874  to parallel the 112.5 windings and put the 8 V 
winding out of phase so it acts  like a buck to make 104.5 VAC.  I'm 
thinking this should get me 756 VAC  to my doubler and give me about 2140 VDC no 
load.  Does this make sense,  am I missing something here? 



For the 8877, I was thinking  about using a voltage trippler.  I have loads 
of extra caps and diodes so  I could take the 868 VAC out, dump it into a 
trippler to get 3680 VDC no load  out.  



I welcome your thoughts and any other suggestions  you guys migh have on 
creating power for these two new tubes.  



Thanks and 73, 

Paul, kg7hf  



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