My
30 years old HY-GAIN TR3-MK3s Thunderbird TRIBANDER need a full
renovation
OKT. 2013
Just for remembering the hard work, I think never will be necessary to do again in my lifetime! I have bin the lucky owner of this very OLD and NO MORE supported antenna from HY-GAIN, for about 7 years, and I have never done anything to it before now. A HAM-friend had to move
to another part of Denmark, and did not have "room for a pony"
on the truck for the travel, so he sold this fine quality antenna to me,
together The antenna have failed
to stay in resonance on almost every 3 band, 10, 15 and 20 meter, for some
month now, and I would like to get my OLD antenna back, the antenna that For long time, I had wishes to take the antenna down for renovating, but the time went by. BUT NOW.... |
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My
little garden-tower is 9,5 meter high, and is mounted on a "TURN
OVER" arrangement, so it is easy to lay down, (look
here...), so 10 minutes after the desertion was taken, all the elements was unmounted and taken to my workshop and the first 2 dismounted. Very soon after this
dismounting, it was clear to me, that all the compression Clamps had to
go on pension. DAY ONE: The first two elements I now polished and remounted, with new clamps, as you se at the picture LEFT. WITCH TWO, DO YOU THINK ?
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Measuring the antenna performing.
DG8SAQ, Tom have done a marvels job with his VNWA software. This is the best investment I ever have done for measuring on anything. Learning to use it is coming by interest, and as I am only AUTODIDACT on electronic, it has taken me some time to get the fundamental things about something called S11, S12, S21 and S22, but I know, that I have to use S11 to measure on the antenna.
All measuring hereunder is done by this fine instrument, I have had since the spring of 2010, an d done in my shack.
Starting with CALIBRATING OUT the cable, so the result is ONLY the BALUN and the antenna.
I have made the antenna so the best MATCH should be in the CW-area (LOW END) of the bands
This
is my first measuring.
The ONLY BAND perfect match is the 15 meter band. Both the 10 and 20 meter band is to LOW in frequency, so I will start trying to tune this. I am a little confused about the resonant (marker 4) at 11.81 MHz, as I do not understand how this could be...??? The BALUN ?? BUT...
I would take a closer look: |
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20
Meter Band:
It is TO LOW, so I have to move the resonant UP in frequency. The explanation for this better RETURNLOSS at -53 db is, that I use 2000 point of sweeping, and here I ZOOM in on a specific part of total, gives me a more precise point of measuring. ( I think ). Maybe there is a problem with this band. The BLUE line is S-11 RETURNLOSS, and the RED line is VSWR For me, it looks promising. |
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15
meter band:
THIS IS PERFECT for me!!!! I work CW and DIGI-mode mostly, so I like this measuring. NO JUMPS, so very stabile measuring. RETURNLOSS better than -32 db |
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10
meter band:
It is TO LOW, so I have to move the resonant UP in frequency. Maybe shortening the elements in the ends will do the trick, we must se... Signal is STABILE with NO JUMPS... AND the SWR is FINE OK..
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SMITH-CARD
and the resonance-points:
Resonance-point is pretty close to center, 50 Ohm.
MORE to COME... |