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Old 03-07-2015, 06:59 PM
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med.3012 med.3012 is offline
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Join Date: Nov 2012
Location: Algeria
Posts: 1,076
Originally Posted by lotec View Post
Hi Med,
Thanks again for your patients and explanation. I was looking at the circuit on page 3-23 under the Don Smith device. Looking at it that way it made a lot more sense. (although I havnt worked with high voltage primary tanks, I still have that to look forward to.)

I think what confused me was. I might have been expecting a step down before the output. The coil as it looks seems like it might step it up a bit.

If I dont have any joy with the oscillator I am working on I will try a culpitts too. I got the data sheet for the npn you are using. One day I hope to stumble across an npn with a bit more power than a signal trans that can cope with those kinds of frequencies.

All the best

You are welcome, high voltage is expected from L2 coil but Lesser voltages can be obtained at intermediate points along the length of the L-2 coil, in this case L2 turns can't be reduced because back and forth waves need the exact L2 length.

if you want to work with Colpitts design in high power, it's better to use Power MOSFET, i think it's difficult to find a high power transistor with higher speed into 20 MHZ ranges.
i lots of work is waiting
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