I have interspersed some comments below....
On 2024-07-24 22:07, Jim Brown wrote:
On 7/24/2024 4:13 PM, kq2m@kq2m.com wrote:
I mentioned "one antenna that does work well even over poor ground",
not the best antenna overall. And it does work very well - enough to
let me work 39 zones and 300+ countries on 80 not to mention being a
very effective antenna in DX contests when the K index is below 5.
I looked at the FCC map, and you're right, Bob, your soil
conductivity is poor. Thus, the principle advantage of your array as
compared to a high horizontal dipole is directivity, NOT gain. And
yes, elevated radials could be a good design choice. But there's a
lot more to radial systems than most hams are aware of -- Rudy
Severns' work, published about ten years ago in QEX, is required
reading for optimizing their efficiency (and thus both field strength
and directivity).
Jim, you've moved the goalposts and now I'm moving them back. I never
compared a 4-square to a high horizontal dipole. You did that. The
first line of my post clearly states above "one antenna that does work
well even over poor ground". Where do you see "high horizontal dipole"
in that? It's not there! You don't get to conflate what I wrote with
what you want to talk about that is unrelated, and then use what you
talk about as a reason to claim that you are correct and imply that I am
incorrect.
My 4-square has gain at low angles compare to a low horizontal dipole
and/or inverted V, which I will define arbitrarily as 70' height or less
for 80. I know that because I modeled it with AO - Brian Beezeley's
excellent program, which I stated previously. And I know it from direct
comparisons at my qth. And, yes the 4-square has directivity as well,
but the gain at low angles from using a low height antenna is what makes
it really valuable to me.
120' high trees on the East coast are rare, so comparing that an Inv V
or horizontal dipole at that height to a 4-square is silly. It is just
not an option here. You have to do the best you can with what you have
available which for most of us are trees ~ 70' - 90' height, and most
places have far shorter trees. The reasons for that are simple - crappy
soil plus ferocious Summer and Winter storms that destroy tall trees.
Yes, with a tall tower you can have access to 120' height, but one
element supported horizontally is very difficult to achieve and not
practical at most qth's in the East even if you were to dedicate one
tower to it and forego antennas for other bands, which is not practical
either. Contest stations almost always use all 6 bands not just one or
two.
On the basis of the serious modeling study I did ten years ago on how
horizontal and vertical antennas are affected by height and ground
quality, I'd take a wild guess and say that its Gain is probably
fairly close to my dipoles at right angles to each other at about 120
ft, and that its directivity in the horizontal plane is significantly
better. I have to get RX directivity from dedicated RX antennas. And
your contesting station is competitive because you're on the east
coast; it wouldn't even be in the game if it were in W6. :)
No Jim. My station is competitive with most other W1 stations,
including those East of me which are the ones that I am concerned with.
Not with the biggest or the best stations, but I am competitive most of
them. And I do well on 80 compared to most of those W1 stations, which
is what matters to me.
The effects of ground are to attenuate the signal in the near field,
the far field, and to form the vertical pattern. Those losses ONLY
affect transmission, not receiving.
Hearing low angle signals louder with a 4-square than a 70' dipole or
Inv V certainly does impact receiving; and very favorably so, as does
the directivity with gain and for reducing noise and unwanted signals
from other directions with clearly improves the S/N ratio. So using the
4-square with Elevated radials benefits me both on transmit as well as
receive.
As to 80M DX -- I've been in W6 for just under 18 years; I'm missing
zones 22, 34, and 40. I have 239 countries on 80. Note that low band
countries count is FAR easier from the east coast than from W6. Yes,
Asia and OC are tough from the east coast, but there are FAR more
countries easily workable from the east coast than from W6. :) So
DXCC achievements are NOT a measure of antenna effectiveness.
Jim, I am TOP of the HONOR ROLL, so talking down to me about where
countries are located might make you feel good but adds nothing relevant
to this conversation. And while it is nice that ~60 EU DX countries are
located in zones 14 and 15 it sure didn't help me with all the tough
Asian/Pacific zones that I worked/confirmed on 80 with my 4-square. JT,
Zone 23, remains the only zone that I haven't worked/confirmed on 80 and
that is only because JT1CO has not been on for the East coast pretty
much for the past 10 years. I'll get Chak someday I'm sure.
Choices of antennas for most of us is strongly dependent on our real
estate, our finances, and what we want to work. Your choice was a
good one for you. That 80M choice isn't even possible for me.
It was never about you Jim. The 4-square with elevated radials IS "one
antenna that does work well even over poor ground" and that is true for
most stations at most qth's, which was why I mentioned it in the first
place. And if ops. only have a choice of using a low Inv V or low
dipole option because of short trees, or absence of towers, or lack of $
to invest, then the 4-square option becomes even better.
I think that this topic has run it's course. If anyone wants to
communicate with me further about it then I ask that they do so
off-reflector.
73
Bob, KQ2M
73, Jim K9YC
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