In a message dated 5/23/01 11:00:48 PM Eastern Daylight Time, d@peak.org
writes:
>
> I am trying to find out to what degree (hopefully by a formula) the
> insulation over a wire will change the required length for resonance.
> In this case I will be using standard 14ga stranded THHN for some loop
> antennas (10-20M range). I have been told (correctly?) that due to
> coupling the plastic jacket will reduce the resonant length for any
> fixed frequency and therefore I should not exactly use the design
> lengths. Fortunately I recently bought an antenna analyzer, but knowing
> the projected modeled lengths obviously would be helpful. If this data
> is in the ARRL handbook I must have missed it.
>
> thanks for suggestions.
>
> Paul
>
Depends on wire type and dielectric. Using house wiring type, solid copper
insulated #12 wire, the shortening factor is about 4%. Use solid bare wire in
the software, then shorten the lengths by 4% when making the loops.
Good luck and don't be ashamed to use your callsign when posting :-)
Yuri, K3BU
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