Antennas with dilectric coatings

See my article "Insulated Antennas" in Communications Quarterly, V3 N1,
Winter 1993 for a graphical method of determining the effect of
insulation. This is based on Richmond, NASA Report CR-2396, available in
depository libraries.
The general effect of insulation is to lower the resonant frequency,
reduce the drive resistance and decrease the SWR bandwidth. Very
approximately, insulation thickness equal to 1.5 times the wire radius
reduces the resonant frequency of a dipole by 10 percent.
For any accuracy, the Thin-Wire program or NEC-4 should be used. I
believe the routine is also in NEC-3.
bobh, W4MB
Received on Sun Jan 28 1996 - 06:31:00 EST