I am attempting to calculate the Pi-L tank values for a GS23b HF amplifier
I am building and I am a bit confused. I know this tube is usually used at
VHF and above but OM power does use one at HF and I happen to have several
of them I would like to use. I need to somehow know the efficiency, I
Think, and either the info for this usage is missing on the data sheet for
the tube or I am not experienced enough to figure it out.
Using a spreadsheet I got from G3SEK. I am using the following values,
3000V on Anode, max of 1A DC anode current and planning on getting 1500W
output, using a K factor of 1.5. So the implied efficiency is 50% and a
plate load of 2000 Ohms, all well and good but 50% seems low and I would
think I would be closer to 60%. If I guess at 61% efficiency then the
plate load is 2440 ohms and I would at 3000v/1A be running 1830W output.
Then to play with this some, if I put in 3000V/.890A and assume the same
1500W out the plate load is 2247 ohms at 56% efficiency, that changes the
second calculation to 55% efficiency with implied output power of 1469W
and 2200 ohms.
Is it safe to assume the 2.2K plate load is close enough?
I am missing something here in knowing how to use the calculations and
spreadsheet correctly. This is not one I want to learn by making mistakes
with HV and expensive vacuum caps.
I can't seem to find anything to help me know what the efficiency
would/should be.
73,
David Trainor
N8ZFM
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