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

To: <amps@contesting.com>
Subject: [AMPS] L-Net calculations: Am I doing something wrong?
From: measures@vc.net (Rich Measures)
Date: Tue, 16 Feb 1999 23:54:02 -0800


>
>>>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?
>
>Sure, I've been asking this question for the last week and you've never 
>entered the fray.
>
>The 4-1000A has an output impedance of 4600 Ohms (according to Eimac) at 
>5KV anode voltage.
>
?  RL depends on the ZSAC.  With higher idle current, RL decreases.  
Using RL=DCV/2 x I-anode, at 0.8A, RL=3.125k-ohms.   Designing for a Q of 
15 at 28MHz, a Pi-L with an intermediate Z of 300-ohms, XC1=208 ohms,  
C1=26pF.  L1=1.5uH.  L2=0.64uH.  C-load=129pF.  Subtracting 10pF for the 
C-anode + stray C, C-tune is 18pF.  The min. C of a UCS-300 is 5pF.  Have 
I missed something?
 
-  later, Jon


Rich...

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


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