de Mike VE9AA again.
A couple folks asked me where I was getting my gain and F/B #'s from.
Fair question.
First of all, I have no doubt the S-meter on an IC-7410 is not accurate, but
everything is relative.
I just performed these measurements moments ago using my AA-230PRO as a
signal source about 200' Southwest of all 3 arrays and also equidistant to
the ref antenna which is an HF9V which also has raised radials. On 20 & 40
this is probably a pretty fair ref. antenna. On 80m, not so much.
I'll express them in S-units, and someone wiser than I can extrapolate to
dB/S-unit if they happen to know it as fact for this radio.
First, all 3-arrays have metallic clutter (or each other), or an 160m
inverted L very much in the near field.). A couple delta loops for 15m & 20m
are also close by.
All readings taken with a SW source/signal generator ~ 200' away.(my
AA-230pro)
>From my understanding an S-unit on a modern Icom is somewhere between 3 -
6dB ?....is it linear from S1-S9 (doubt it)
20m
HF9V - S7
Array - SW - S8
SE - S2
NE - S1-2 (varies a little with the wind.call it S1.5)
NW - S3
Gain over ref 3-6dB? F/B 18-36dB?
40m
HF9V - S5
Array - SW -S6
SE - S2
NE - S2
NW - S3
Gain over ref 3-6dB? F/B 12-24dB? Low due to being nested inside NW
quadrant of 80m array?
80m
HF9V - S5 (unfair reference)
Array - SW - S8
SE - S3
NE - S0 (could hear signal, can't measure it)
NW - S6 <ouch; would've thought # should've been lower here,
however this array aimed NW is aiming at all other antennas and a garden
shed, cars, etc. so maybe I should not be surprised)
Gain over crappy vertical 9-18dB? (real gain 3dB?) F/B Excellent @ 24-48dB
So, it's obvious it all doesn't work perfectly, and F/S seems to suffer a
little here and there, but compared to the reference antenna, they have some
gain and F/B is pretty good. F/S is fair.
I don't know if at only 200' away this is a fair or accurate test.
Mike VE9AA
Mike, Coreen & Corey
Keswick Ridge, NB
From: Mike Smith VE9AA [mailto:ve9aa@nbnet.nb.ca]
Sent: October 14, 2016 11:22 AM
To: 'towertalk@contesting.com'
Subject: Wire 4-squares - they work ! (long)
de Mike VE9AA (long)
I've received a few direct emails and also some questions on some of the
smaller reflectors and chat pages I belong to, so though I would just post
my *experience* with these here for you to collectively ruminate.
Keep in mind, I have done very little with them yet. Some DXing, a 1 hr
CWT(contest-sorta thing) and some listening. I am an EE Technologist, not an
E Engineer and I couldn't run NEC-4 or any other antenna modeling program to
save my life. I am just a regular guy who loves contests and does a little
casual DXing, and am relating my experiences and not trying to convince
anyone I did anything better than what more knowledgeable Engineers or real
station builders would do. Thus, take all this with a grain of EE salt.
A few days ago I installed my 2nd 4-square; one for 40m. Already have a
small one for 20m(tnx Bob!). As fun as it is to use I am nearly sure a 3-el
yagi at 48' would woop the 20m ones' butt.(but I have no towers and it is
quiet) I am sure the 40m one will be a couple S-units down from even a
2-element shorty-fourty up high, but it's QUIET. Direction switching is
nearly instantaneous. In the CWT with a disturbed Ionosphere, I found that
beaming SE (towards ZS6) I was able to work some of the big W1's/W3's on
what sounded to me like backscatter. I've never owned a beam on 40m, so I
can't say for sure. Beaming SW(true bearing) their signals went way down.
Two nights ago I finally got my 3rd (wire) 4-square working..80m 4-square -I
really never expected much based on the 20m & 40m ones,(20m one is "meh"
(but quiet) and the 40m one is pretty OK, but feel it could be a bit better,
gain wise.
The 80m one though.WOW---I just had to share this.. I was already working
EU's about 50mins before my SS (Sunset). (big stn OK1AWZ w/a 3-el beam
followed by a string of other stns).....a couple hours later I worked VU2GSM
@ his SR (sunrise) Kanti is running medium power and a dipole in a noisy
environment. I never heard him work any other NA or even heard any other NA
callers the few times that I tuned by. I was running around 600-700w on 80m
cw. (the next night I worked Kanti on 40m and still never heard any other NA
callers|). Maybe everyone has already worked him on 40 & 80m..don't know- I
don't do much Dxing..just now and then, so perhaps he's quite popular)
I am sold. Wires in trees that ACTUALLY work ! Call me a believer.
I am already resigned to the fact I'll have ongoing maintenance issues with
it, as its 100% made of wire & rope, in the woods supported by trees that
sway and has 2 raised radials* each, some of which the deer *will* get
caught up in. ( I already know this from previous antennas) The verticals
are black #14AWG stranded/insulated R90(?) and the raised radials are
*galvanized steel fencing wire(partially because some are low and deer will
fight with them and partially because copper is bloody expensive here). For
the radials I carefully made a hz dipole and tweaked them to resonance at 5'
above ground. For the first vertical I installed the whole antenna, but my
calculations were bang on and I did not need to tweak it. Just made 3 more
and I was in business. I also measured my RG6-type feed lines as 82.5% vf
as opposed to the advertised 84% vf. Cut so X=0 at the bottom of each band
if my memory serves.(AA-230pro)
In this tiny stand of sloping woods that is <0.2acres I have some standing
dead trees and some "widow makers", and lots of deer that pass through it
literally daily, so things will become damaged over time, I am 100% sure.
Everything is contained within the "box" or "square". As viewed from above,
there are no wires extending outside of the box and no wires going towards
the center controller (except coax of course). Two raised radials per
vertical. (would 4 or 8 work better? Yes, most likely..but I was out of
space!)
On each side of the square, 2 radials (one for each vertical) pass close to
one another (about 1 foot). I found my 20m array that's NOT in the woods,
and is contructed is quite similar but uses aluminum verticals is very
twitchy when it comes to radials passing close to one another so I tried to
be creative in getting some good spacing on the 40 & 80m ones. Did it help?
Don't know.
What I find is that they are so quiet as to almost not be believed. I live
out in the country on a Ridgetop @ 660'ASL and except for a nagging electric
fence to my NE I have always thought I had a quiet QTH. Even the 40m one is
eeerily quiet. I heard VP9/AA1AC last night at s5 on the HF9V(lots of
raised radials) but the atmospheric QRN was bad. Switched to the 4-Sq and
he was maybe only S6+, but hardly any noise. First call,(@100w only) and he
was in the log. (a pileup of on top of him too....maybe that was unfair as I
am relatively close and I am sure most of the pileup was either EU or from
out west W6/W7).The 20m one does not work quite that well however it is also
vy quiet. As I said, a normal tribander would likely beat it on 20m.<<
comments?
Took me around 2-3 weeks to get all the wires up in the trees(fishing rod &
golf ball method-not easy on rocky/mossy sloped ground with trees every
10-15 feet, but doable), phasing lines built and control lines run. All
vert's and raised radials are suspended by ropes. The bases vary from 3.5'
off the ground to about 8' off the ground, as the patch of woods they are in
is sloping (nw-se) very badly and I was attempting to keep them as level as
possible. The pain in the wallet was moderate for the Comtek contollers
once I paid for them, then paid exchange, taxes, duty and shipping , , but
probably cheaper than separate 40m and 80m yagis on a tall towers ;-)
I do not employ any coils and/or caps on the wires or ferrites (K1TTT) on
the RG6 feedlines. Before anyone tells me 120 gnd radials per vertical is
much better ; I will not ever be putting down any ground radials in this
patch of woods. It's on a steep slope with lots of rock underfoot as it's
on the edge of old farm land and 50+ yrs ago they cleared the field I live
on and rolled or tossed all the rocks "down over the bank" so walking is
precarious at best, with leaves and moss on top of rocks. Can't do gnd
radials here. The most I could probably do with these is to add 1
additional radial pointed towards and passing by, the Comtek controller. I
don't see a need at this point.
My stand of woods is really too small and I had to compromise on the 80m
spacing (way too close @ 62.5') but it seems to work anyways. Also, all my
80m ones are "inverted L's" as most of my trees are too short.(35-45' for
the most part) AC0C says they just "want to work" and Jeff is right. I
agree wholeheartedly. N8UM has been using 4-squares on most all bands and
swears by them. He is wise.
I am so excited about this type of antenna that I just had to share. Can't
remember the last time an HF antenna worked so well for me. Perhaps in the
early 90's when I actually owned a tower and had a TH6DXX that really kicked
it? There are no towers here at all and no plans for any. Would a 2-el 40m
shorty forty @ 100' work better? Probably. Would a 80m rotating dipole @
150' work better? Probably. Can I afford that? Nope. (hi)
I should mention, too, that the 40m 4-square is partially nested inside the
NW quadrant of the 80m one. I don't notice too much in the way of
degradation of F/B on either, but have not made too much in the way of
measurements with locals yet..with QSB, hard and fast measurement are
difficult to quantify.
If you have a chance and have trees in your back yard, I recommend them at
least on 40 & 80 ! (I still haven't heard from a single soul, nor found an
example on the internet of anyone who's compared a 4-square on 10, 15 or 20m
with a normal tribander @ 48'....I am curious about K3LR's claim.)
I'd like to hear more about YOUR <wire> 4-sq arrays and what has worked for
you.
Next up is a 2el PVS-2 for 160m..maybe for CQWW
Mike VE9 Antenna Antenna
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