Re: NEC-LIST: Efficiency of Short Dipoles

Hallo Prof. Baker,

I just noticed your reference to mu(r) of stainless steel rope as a
potential source of additional loss in HF antennas, presumably
because:

skindepth = 1/sqrt(mu * sigma * constant)

and hence losses increase proportional to sqrt(mu(r)).

My information indicates that mu(r)= 1 at HF frequencies for most
steels, irons and other non-laminated metals.(gyromagnetic limiting
frequency approx 20 kHz).

Am I understanding your concerns correctly and/or have you measured
higher mu(r) values at HF frequencies for any stainless/silicon/mild
steel?

Andre Fourie

Tel: Intl + 27 11 4030380
Fax: Intl + 27 11 4030381
Website: http://www.poynting.co.za
email: fourie_at_poynting.co.za
Papermail: Dr APC Fourie, PO Box 318, Wits, 2050, South Africa
Received on Wed Dec 10 1997 - 09:39:44 EST