"Reg Edwards" wrote in message
...
I wonder what the quarter wave frequency would be for a length of wire
30"
long with a base coil of approximately 0.330uH. Same wonder with a
0.660
uH
coil.
====================================

Rich, wonder no longer.

Download program BOTLOAD2.

For a 30" rod -

With base loading coil 0.33 uH, Fres = 69.1 MHz.

With a base loading coil 0.66 uH, Fres = 55.7 MHz.

The antenna has three radials, and each has a loading coil right at the
begining.

Now I would have thought that at the feedpoint, the impedance would be low,
so I think then one would assume the radials are suppossed to acting as 1/4
wavelength radials. If that were true, then the freqency at which the
radials are quarter wavelength would be the operating frequency of the
antenna.

I've remeasured the coils after removing the rubber insulation to get a
better look.

For Radial #1

Length: 6mm
O.D.: 11mm
Turns: 9
Pitch: closewound


For Radial #2

Length: 6mm
O.D.: 11mm
Turns: 9
Pitch: closewound


For Radial #3

Lenngth: 13mm
O.D.: 11mm
Turns: 20
Pitch: closewound

I wonder if the coils should all be different, but by mistake the radials 1
& 2 are identical. I just don't know.

The new length of the radial is 72mm orabout 28.5". They are 2mm diameter
stainless steel rods.

I tried to use Botload2, but not sure what I'm doing. Can you please do the
two calculations again Reg? Ta.