OK, so I just put up a 20m 4-square using a COMTEK box. So far, I'm a
fairly happy camper. First real gain antenna on 20m in 11 yrs. (gain being
a subjective term here)
Installed the first skinny vertical. 2 raised radials @ 90 degrees to one
another. The vert's about 2' off the ground and so are the 2 radials. SWR
curve looked really awesome once I tweaked the length of the radials and
vertical element.
I was in heaven.
Unfortunately the way it's arranged, each vert only has 2 raised radials and
if you were looking at it from overhead, you would only see a square and a
vertical at each corner. The raised radials for each vertical are adjacent
to one another. I tried 1 radial each, but SWR was high no matter how much
tweaking I did or what angle(s) I had it at. I cannot do ground radials,
nor radials extending out past the 4 lines of the 17.5'x17.5' box. I could
do one more (very bent) radial towards the center of the box, but that's
it. I don't think it would help. I digress.
I put up 3 more verts and built them as close as I could to the original.
Carbon copies.
Let's not talk SWR curves, but how to go back and retweak all the verticals
independantly? What I am seeing in the shack baffles me. *(must be the
hybrid cct in the external box doing weird things to my SWR analyzer) I am
going round and round.
When I was doing the 2nd vertical, I tried shorting the center to the braid
on the original but in all honesty I don't think it made much difference.
The array is "working" (F/B great, F/S is "MEH", but I am not really seeing
any gain in the favored direction that I can quantify over another vertical
50-60' away. (HF9V). It IS much quieter and that's really nice and I do
hear W1's on backscatter (vy weakly) that I cannot hear on the HF9V(QRN) but
I see no real difference on the S-meter on signals above the S1-QRNy noise
floor. I am looking for 3dB (or that's my hope) Some SSB signals sound
different on the 4-SQ compared to the HF9V, so I am presuming a different
incoming angle or possible a dB or two of gain, but nothing I can measure.
The quietness is comforting, due to some noise to the NW and other small
sources in other directions.
I have a ton of questions and probably could give lots more details on how I
have this thing built and why only 2 raised radials etc., but if I could
nail down detuning the "other 3", I think I would be on the right road.
Bottom line, what's the best way, short of taking down the "other 3"
verticals to detune them? (could I clip a 4' wire onto the bottom of them or
something?)
I have not yet measured dumped power into the dummy load. Antennas are
~150' from the house and it's been raining here, so quick dashes outside
only...just got control cable working at suppertime. I can enlist my son as
a helper to do some key down sessions once the wx clears this weekend. I am
told the frequency at which I see the least power dump is where my array is
most resonant and has the most gain at ?
TKS
Mike VE9AA
Mike, Coreen & Corey
Keswick Ridge, NB
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