[1000mp] Litz wire, etc.

[w7xu]

Hi Tom,

Regarding Litz wire and lower frequencies -- if the FCC decides to
give us an LF allocation (136 or 160 kHz?) I plan to get on the
band.  Even my 120 ft. vertical will need a relatively large loading
coil for those frequencies, and I had set aside some Litz wire to
wind a single layer coil for that purpose.  Are you saying that
using the Litz wire is probably unnecessary?  Or will the advantages
out weigh the extra losses at 136 kHz?

Thanks for your time.

73,  Arliss  W7XU

> Litz wire is effective only because it reduces eddy currents in the
> wire when used in transformers and multi-layer coils, not because of
> wire resistance or unit inductance of the wire. As a matter of fact,
> Litz wire has noticeably more resistance-per-foot than solid wire of
> the same diameter at every frequency, from dc to whatever.
> 
> The benefit of insulated strands is in preventing or reducing
> circulating currents where the wire cross section acts like a big
> copper plate with eddy currents, and the advantage only occurs in
> multilayer coils and at lower frequencies (normally below 1 MHz). A
> solenoid coil or straight conductor using litz wire always has lower
> Q and more loss than an identical coil wound with solid wire the same
> size, material, and insulation type.73, Tom W8JI