I found formula in Duane Bylunds book "Modern Tesla Coil Theory" which says
that the Load impedance for a Class C amplifier is approx: R = V/2I. I think it may have
something to do with it being Class C operation. And in a VTTC where we're using raw
A/C... this may be why it needs to be R = V/4I. Something to do with the conduction
angle maybe. Since the tube is not conducting steadily, it can tolerate more power to the
plate without burning up.
John
-----Original Message-----
From: David <zipo@xxxxxxxxxxx>
To: tesla <tesla@xxxxxxxxxx>
Sent: Thu, Jan 18, 2018 8:29 pm
Subject: Re: [TCML] Tube Q
John - Thanks, I understand. You just said a wealth of info in your second paragraph because that is exactly what I have noticed. My 810 coil is working very good and it's Q is way off by calculation. A fresh new old tube makes a world of difference.... :)DaveOn 1/18/2018 5:29 PM, Futuret via Tesla wrote:> Dave,>>> I used to know, but I can't remember. It's somewhere in my> hand-written notes. Maybe someone else will have the answer :-)> I may have gotten that from Ed Phillips originally. Not sure if> he's still on the list.>>> By the way in my tests, the primary Q didn't seem to make much difference> if it was 10 or 20. I didn't see any difference in performance, maybe> because of the effect of the loading by the secondary and sparks.>>> John>>>> -----Original Message-----> From: David <zipo@xxxxxxxxxxx>> To: tesla <tesla@xxxxxxxxxx>> Sent: Thu, Jan 18, 2018 5:08 pm> Subject: [TCML] Tube Q>> I have been going over some of the math for my 810 tube coil and I have> a question for John.> John - You have been credited with multiplying plate current by a factor> of four for calculating tube impedance to be used for determining tank Q> (plate V/4*plate I). Why Four? as opposed to just plain (plate V/plate I).>> Thanks John and everyone>> Dave>>>> _______________________________________________> Tesla mailing list> Tesla@xxxxxxxxxxxxxxxxxx> https://www.pupman.com/mailman/listinfo/tesla>> _______________________________________________> Tesla mailing list> Tesla@xxxxxxxxxxxxxxxxxx> https://www.pupman.com/mailman/listinfo/tesla_______________________________________________Tesla mailing listTesla@tedward.pupman.comhttps://www.pupman.com/mailman/listinfo/tesla
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