Dick
>Rich...
>
> ........
>........... Time to do your homework.
>
? I did the homework, Dick. I built the Pi-network test model. I used
Ian's calculated values for: 2000-ohms RL / Ro=50-ohms / 7.00MHz / Q=10
or so.
- Ian's results:
"The accurate formula - in ARRL Handbooks since 1995 - gives
C1=102.1pF, L=5.57uH, C2=463.9pF. When analysed with the load present,
this checks out with Q=9.98. "
- My results . Without RL and Ro, the resonant freq. was 7.37MHz, which
checks out mathematically. When I connected the 2000 ohm and 50 ohm
resistors, the resonant frequency did not appear to drop to 7.00MHz as
had been predicted.
Is there perhaps something that I am doing wrong, Dick? . Ian? . Tom?
. Peter? Any suggestions would be greatly appreciated.
>
>-----Original Message-----
>From: Rich Measures [SMTP:measures@vc.net]
>Sent: Friday, August 06, 1999 2:17 AM
>To: amps@contesting.com
>Subject: RE: [AMPS] Pi-Net math
>
>
>
>
>>
>>I'm with you, Ian. Someone on this reflector very recently stated the
>>basic, fundamental definition of "Q" as "(energy stored)/(energy
>>dissipated)." I think "per cycle" is usually added. Ultimately that comes
>>down to the very general form of X/R or R/X.
>>
>>Seems to me the fundamental fact Rich continues to ignore is that you can't
>>define a loaded Q, which is what we're inherently dealing with in matching
>>networks, without including the dissipative element(s).
>
>Eimac defines Q using RL. Q = RL/XC1. My contention is that with RL
>and Ro connected to the Pi-network, the resonant frequency is neither
>decreased nor increased.
>.....
>
>
>Rich...
-
- Rich...
R. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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