Mark Keith wrote in message
om...
"Chuck" wrote in message

A reduced-noise (E-field loaded) vertical
for 40m with a VSWR bandwidth of 1.3:1
from 7.0 to 7.3 mHz, (it's not a dummy
load as one would generally deduce from
the above description), and has proven to
be as good a performer on DX and local
as my conventional top loaded vertical.

What is E-field loaded? Not sure what you mean with that...

The conventional vertical sees a noise
level here of around S-7 or greater, and
the E-field loaded vertical, around S-3 to
S-5 (on IC-756, normal BW, no NB, no
DSP).

I'd be very leary...Also would depend on the polarization of the
noise, and any possible changes in the pattern...But in general, if a
certain vertical picks up more far field noise than another, it's the
superior vertical. Noise is rf like any other signal. So unless I'm
missing something here, the conventional antenna should also receive
the *desired* signal better than the low noise version. And being
things are generally reciprical, it should probably transmit a better
signal also...How careful have your on the air tests been? Are you
quickly A/B'ing using a switch?
Needless to say, I'm kind of dubious of the claims of equal
performance. Unless the noise was common mode or polarity related,
I've never seen an antenna that received lower noise, outdo one that
picked up more noise. If the change is not efficiency related, that
would leave me to think that your vertical pattern is being skewed
somewhat, and is more horizontally polarized than the other, and thus
, picks up less vertically polarized noise. If thats not the case, I
would think the low noise version is less efficient. Just my opinion
tho...

Neither of these were developed using
computer modeling, though.

Neither were my comments...:/ MK

Hi MK,

When I stated:
(it's not a dummy
load as one would generally deduce from
the above description)
I wasn't joking. The fact that you've
never known a vertical antenna to
behave in this manner, is not surprising.

The purpose of my experiment was to
investigate the possibility of loading
(shortening) an element while still
maintaining a relatively normal BW.

Avoiding parallel wires and coils, the
resulting loading system is what I
call E-field loading (perhaps a poor
choice of terms) - a method of
conductive loading that resulted in
reducing the off-resonance reactance
in the FP. I suspect it is effecting the
susceptance of the voltage loop in
some way. The unexpected bonus, of
course, was a reduced susceptibility
to electrical noise.

73 de Chuck, WA7RAI