From: "Gary Patterson" <gpatterson53@hotmail.com>
> ok.... one guy says use the "open circuit voltage" the other guy say use the
> loaded "operating voltage" ..................who is correct
Assuming you're making an adjustable matching network, you should be able to
match a range of tube impedances while maintaining network Q within 12-15. Use
your program to do some preliminary runs and pick inductance values for each
band (assuming a pi-L) that fall within range. Then run the program again,
specifying those inductances, but changing the Q and load impedance. This will
give you the required ranges of tuning and loading capacitances. For example,
for a pair of 4CX800As in the works here, I got these numbers for 160 meters:
160 meters, L = ~13.6 uH
Z=1460
Ct = 595
Cl = 2760
Qo = 12
Z=1820
Ct = 602
Cl = 3236
Qo = 15
Ct is the plate-tuning cap, Cl is the loading cap (pi network, one inductor). I
got similar results for 80 and 40 (it's a triband amp). By making the loading
cap large enough I can cover the range of load impedances (depending on whose
formula you use) with the same tuning cap and inductance.
73,
Jim, KR1S
http://kr1s.kearman.com/
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