Jim, trying to understand the source of the high resistance that is
frequently mentioned for choke design.
I can see one scenario where a series to parallel conversion might explain
it. Say 400 ohms xl in series with 20 ohms R would transform to 8020 R in
parallel with 401 ohms xl. Added shunt C would increase the effective xl up
to the point of resonance.
Is this a possible explanation of the fundamentals?
Thanks/73,
Gerald K5GW
In a message dated 5/20/2014 8:02:27 A.M. Pacific Daylight Time,
jim@audiosystemsgroup.com writes:
On 5/20/2014 7:05 AM, Jim Thomson wrote:
> if any choke is high resistance, it will work..provide the Z is sky high.
> Power is still I squared x R.
Yes. I have shown in my tutorial why choking Z on the order of 5K ohms
resistive is a suitable design goal for most installations, and W8JI has
reminded us of some where that's not enough. The only string of beads
choke material that can get anywhere close to 5K on HF is the #73
material that W2DU chose, and you need several hundred of them to get
there. You would need that higher value for the high power amps you like
to use. The largest #73 material bead is just large enough to fit coax
like RG303. There's a discussion of his choke in the two referenced pdfs.
73, Jim K9YC
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