sg v tube coils

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Original poster: "Bob Jones" <alwynj-at-earthlink-dot-net> 

Hi all,

I thought I would share some ramblings on the above.

My sg coil has a bank size of 6J say 3J in the output.
How can a tube coil produce a similar output.
If I assume the power available from the tube is 3kWpk then it must flow 
for at least 1ms to build up 3J.
if I again assume 50% transfer that's 2ms.
Lets say that both have the same coil and topload but perhaps different turns.
What frequency must the tube coil operate to get out the 3J.
Lets assume the time constant of the secondary is 50 cycles (some factor of 
the Q) then it will take say 100 cycles to limit.
Hence the maximum frequency of the tube coil can not be greater than 20KHz 
with a Q of 50..
i.e. you need time to get the energy in so you need high Q and low f.

Next issue.
Lets assume  100pf for the ouput C. Then the output voltage required is 
245kV. Ignoring the fiddle factor for dis C.
Then peak reactive secondary power ( pkre defined as the scaler product of 
Vc and Ic) is 754kW.
If the Q is 50 then the power loss is 15kW but we only have 3kW of real 
power available!!!!
We would have up the Q to 250 to get back to 3kW. At 20KHz how?
With a k of .25 thats about 12kWkW sloshing in and out of the primary.
But we have only 3kW input so we need a gain of 4.
So the primary tank has 4x turns with the anode connected to 1x
I think I have to use reflected impedance with K and secondary turns to 
calculate the actual number of turns.
The peak primary voltage would be 6kV for the primary C at 8A, doable, 
given tube 1500V at 2A.
We could just put 4 tubes in parrallel for 6kW.
I forgot the pk to rms factor but its still a comparison.

Comments.

Bob