Roy,
You have to watch about using Ohmites information. The reason being is their
chokes aren't wound with copper wire, but are with resistance wire. That has a
big thing to do with self resonance, or what an Ohmite engineer told me. Even
though it's not a large resistance, using resistance wire supposedly moves the
chokes self resonant point a good distance from where it would be using copper
magnet wire. I've never set down and investigated that any further, I just
remember the conversation I had with the engineer. I had asked because the SR
points didn't jive with everyone elses chokes being made.
Best,
Will
*********** REPLY SEPARATOR ***********
On 8/25/05 at 11:49 AM Roy Koeppe wrote:
>Said,
>
>
> "...Circulating current is limited by
> parallel resonances in the winding,
>
>At 1.8MHz, with a typical Ham amplifier - I don't think so..."
>
>
>Follows is published data pertaining to Ohmite plate choke model Z-7,
>operating range 3 to 20 mHz, 84 uH, core dimensions 6" x 9/16"...
>
> "Rp (apparent parallel resistance) at 3 mHz -(brace
>yourself)- is appreciably in excess of 200,000 ohms".
>
>I must assume that their 1.8 mHz model, if they made one, would have the
>same low-end specs.
>
>I also agree that manufacturers do try to cram 160M into a single plate
>choke with high compromise. Still 3000 ohms is a far cry from 200,000.
>
>73, Roy K6XK
>
>
>
>
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