Re: NEC-LIST: cross field antennas

Chip,

        The elevation testing was to determine if the ground was
influencing the antenna operation. My premise was the following
... take a dummy load and test the input impedance at various
elevations. The impedance should not change ( of course ) unless the
coax was radiating etc etc. I am treating the antenna as a dummy
load. If the ground was involved I would expect to see a change in
impedance ( my equipment detects phase and / or amplitude variation at
the feed point ) with varying elevation. My understanding of the CFA
is that it should operate like a light bulb ie you pump RF into it and
it radiates. ( ie no groundplanes etc )

I was using the term isotropic radiator to indicate that the antenna
does seem to operate like a light bulb ( ie ground independant ) and
point source radiation in horizontal. ( well I have not done vertical
FS testing ).

I have not made formalised field strength tests as such though I do
use a remote sensing FSM to determine if anything is being radiated. I
have used the antenna on @ 28 Mhz and made successful contacts but
have not revealed that I was using it to the other party. I tried
briefly to compare FS with a 5/8 groundplane at elevation of 8 meters
but was inconclusive.( radiation patterns are not comparable I
suspect )

However I really need a 50:377 ohm broadband transformer the impedance
ratio is critical.

regards & 73.
Received on Fri Feb 12 1999 - 07:38:26 EST