wrote:


Hi Mark. What's your/any definition of "par"in this context? What other
40M antenna did you A/B test against your GP on the air?

Directly, my 40m dipole at appx the same height as the base of the GP.
I also compared with the earlier ground mount with 32 radials, but
not directly, as the same radiator was used on both antennas.
When comparing the dipole and the ground mount vertical at 1500
miles, they were almost always about the same. Tested many times.
In comparison, the GP would always beat the dipole by 2 s units
at 1500 miles. Again, tested many times over a period of time.



But...My conductivity rating in
this area is bordering on the "30" range being I'm not too far from the
coast.

.. . maybe someday I really will download that map . . Not that I can do
anything about what it tells me about the ground condx in my particular
neighborhood .
.................................................. ..................

It also occurs to me that the ground off in the far field would effect
also. Being most all of this area is rated pretty well, that could be
a factor as far as low angle dx stuff... ??

I know for sure Cecil would need more radials than mine for
the same performance, as his was half the height and his ground
rating is lower. .
My hunch is if you had 8 radials on the GP, it probably would have
done better.

Maybe, maybe not but realistic modeling elevated HF GPs would at least
provide some hints. Maybe.

Dunno. I've modeled mine, and for it to mimic real life at this qth, I
always
had to boost the ground quality in the program.

From what I've seen, heard and read over the years there's a whole

bunch of smoke, mirrors and mythology wrapped around the effects of
radials as they relate to current-fed HF verticals. Reg Edwards
"endfeed.exe ' ditty looks like it debunks a bunch of the mythology. In
any event and with all due respect I'm not about to get into
nit-picking any of it.

Dunno. Haven't seen that yet... But I'm a pretty firm believer in what
I've seen written and graphed as far as the number of radials needed
to equal a certain performance of a ground mount. The lower in WL,
the more you need, of course.

The situation I described was a sort of very subjective A/B "shootout"
between my two 40M antennas as transmitting antennas and the so-far
strange and unexplained results I got and I seriously doubt that my
results would have been noticeably different if the GP had four more
radials. My voltage-fed inverted L seriously and consistently
outperformed the GP on long-haul contacts as a *transmitting* antenna
to the tune of at least one s-unit, sometimes more particulary into the
north Pacific, at the far end. But the two antennas seemed even-up when
*receiving* on my end.

*This* is the weird part to me... I've rarely seen antennas not act
reciprical as far as transmit/receive... Thats kinda unusual...

That's the issue Cecil brought up. The only
"radials" I had under the L was a three foot long #14 wire which ran
from the cold side of the tuner to a copper-plated eight foot steel
ground rod driven a few feet into the ground. It BOOMED. The GP did
not.

Hummm....Still the only rational explanation I can think of is the
GP needed more radials... Can't really think of any other reason,
unless maybe the general takeoff angle was a bit higher with the
GP, and again, that would tend to point to mediocre ground at , or
in the far field of the antenna. Can't really think of anything else,
unless maybe the radiator was a poor conductor, etc...Kinda doubt
that though...



I've never tried 1/2 waves on the low bands,
except for extended inv-L's...I have run them 20m up though.
Work well there.

Seems like they work nicely. So far my only measurable current-era
experience with true ground-mounted half-wave "dipoles" came about when
I operated portable for an extended period a few years ago and strung a
coax-fed 20M dipole up into a big maple tree with the bottom end of it
a foot or so above the ground. Lousy location, halfway down a hill on
one side of a mini-valley but "I worked every station I called". Heh.
..
All of my 1/2 wave verticals have been base fed so far. I usually use
the "gamma loop" type of feed. But...All those have been elevated,
not ground mount.

Anyway I'm on my way into a new location. Tiny property which will host
several voltage-fed HF verticals because of their minimum-size
footprints. Along with the verticals the property also hosts a rather
swampy bamboo farm. Big suckers too, maybe I can raise my own quad
spreaders. What do you 'spose the ground resitivity and permitivity
might be? Reg and Nec-Win- Plus want to know . . .

Dunno, but the conductivity map might give a general idea. You can d/l
those things somewhere. But...Forgot where I got them.. I've
got some I d/led that are in full color, and have separate charts for
the
various areas of the country. But there is also a little version in the

ARRL antenna handbook I think.. Texas is kinda weird as far as ground.
It's real good at the coast "30", but drops to 15, or even lower as you

venture north up into central-east Texas. But there is a hot zone that
runs up through Dallas, and father up into the midwest, that is rated
at 30. Cecil is in the poorer "middle" zone between the two good
parts.. It's quite possible my GP did well cuz of the decent
ground
quality both at the antenna, and farther away.
You should have seen my mobile on 40m at the beach a few months
ago. I was parked right on the water nearly, and using my maximum
length 14 ft antenna, with the loading coil at 8 ft up the whip.
"antenna
base at appx 64 inches from the ground, on the cab of the truck"
Absolutely was kickin butt...I was keeping up with home stations
running KW amps when yik yakking with various stations across the
country. Was consistantly one of the louder stations to whoever
on that freq.. Some were in FLA, some out west, etc.. And I was
just running 90-100w from my 706. I blame it all on the
salty ground and seawater... If that 14 ft antenna did that, just
imagine what my full size GP "should" have done at that location.
Dunno...I think it's all in the ground quality and radials.. Can't
really
explain it any other way.
MK