[AMPS] L-Net calculations: Am I doing something wrong?

Rich Measures measures@vc.net
Tue, 16 Feb 1999 07:50:06 -0800




>>€   36pF of Cout should pose no problem for a conventional tank -  
>>Provided the anode current is max. and C-tune has a minimum of <10pF.  // 
>> It seems to me that those who propose using an L-match between the anode 
>>and C-tune, fail to consider that the added L also decreases the anode 
>>vhf-resonance.  This could be problematic, depending on where the 
>>RF-grounded screen (or grounded-grid in cath. driven config.) resonance 
>>happens to fall.
>
>Yeah but Rich, 36pF in Cout of a tube is a large amount of capacitance.  

€  For a high-current tube, 36pF is not a problem on 10m, Jon.   The 
critical factor is the ratio of the anode-C's X-ohms (160) to  RL-ohms.  
.  

>Depending on his output impedance, he may have a very difficult time 
>matching with that much capacitance and still get a Q that is overly 
>large.  With the 4-1000A, there is no way to match its high impedance down 
>to 50 Ohms and still get a good Q w/o doing this transformation.
>
€  Wanna bet a large pizza with 4-toppings?


Rich...

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


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