[QRZ.com via rec.radio.amateur.moderated Admin]

Antennas, Feedlines, Towers & Rotors

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Antenna comparisons.

Posted: 02 Oct 2017 01:32 AM PDT
https://forums.qrz.com/index.php?thr...risons.583222/

Gday all, the last few days have been quite revealing for me in forcing me
to re evaluate a lot of gospel antenna theory as a result of antenna
comparisons.



Of late, Ive been able to directly compare, both for 20 m, a quarter wave
elevated ground plane vertical and a horizontally polarised Delta Loop and
the results have been a little unexpected.



Firstly and probably expected, the loop is much quieter than the vertical
with almost zero on the S meter and S 5 to 7 on the vertical....



Antenna comparisons.

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Vertical Yagis

Posted: 01 Oct 2017 09:30 PM PDT
https://forums.qrz.com/index.php?thr...-yagis.564307/

This came to me in a dream about DXing. Why not take the standard Triband
beam and instead of mounting it horizontally, MOUNT IT VERTICALLY! Would
this not bring the radiation angle down to ZERO? ...putting a stronger
signal into the DX location. To remove interference from supports, I would
get a 50 foot utility pole to mount it on.

HAS ANYONE TRIED THIS? or done research on this idea?

LAYNE AE1N

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Phasing Lines on TA-33MW

Posted: 01 Oct 2017 07:45 PM PDT
https://forums.qrz.com/index.php?thr...a-33mw.583210/

For those of you that are familiar with this antenna, is there any reason
one cant use a piece of copper wire in place of the aluminum phasing lines
between the elements? Im starting to tune up the station for the winter
and noticed one of mine has a crack where the coax attaches.

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Matchbox Antenna (9:1 Un-Un) who's using one, questions

Posted: 01 Oct 2017 07:19 PM PDT
https://forums.qrz.com/index.php?thr...stions.583192/

Ok so short story is I had a fan dipole for 40m and 20m. It would kinda
work on 10m, but not well.



Hurricane Irma split my tree and screwed up my dipole. BTW storms have
wrecked my dipole about 5 times and its no fun climbing this tree.



So, I decided to try a 53 inverted L on a matchbox (9:1 un-un). I shot a
line into a tree and pulled a vertical up and over the tree... yay no tree
climbing, and I could cut my coax length in half.



SURPRISINGLY it actually works quite well! Im...



Matchbox Antenna (9:1 Un-Un) whos using one, questions

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Mast recommendation

Posted: 01 Oct 2017 04:33 PM PDT
https://forums.qrz.com/index.php?thr...dation.581911/

I KNOW Ive seen this discussion on here before but for the life of me, I
cannot find it.

I have no problem buying a Rohn Mast from DXeng, but I have a big problem
with the 100 delivery charge.



I believe some pipe that Depot stocks works fine.



Universal Tower-40

Mosley Tribander with future of 40 and WARC add-on kit.



Let me know!

Thank you

Ryan

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OCF dipole question

Posted: 01 Oct 2017 04:13 PM PDT
https://forums.qrz.com/index.php?thr...estion.581696/

im building an OCF for 40m. I measured 45 on one side and 22 on the other
side of the antenna for the dipole wires (67% of the length on one side and
33% on the other). Now for the question...on a regular dipole where the
sides are equal, you lengthen/shorten each side equally. On the OCF, since
one side is twice as long as the other, do I adjust the long side twice as
much as the short side (1/2" short side, 1" long side)?

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Tuning Cobweb antenna

Posted: 01 Oct 2017 03:12 PM PDT
https://forums.qrz.com/index.php?thr...ntenna.553346/

hi all, I have just finished my cobweb antenna (G3TXQ type) and its looking
good.I have to initially tune it at about 3.5M before I raise it 13M on the
tower.

What I wanted to know will the resonant frequency incrase or decrease when
I raise it from 3.5M to 13M and by about how many Khz will the resonent
frequency be expected to change.The reason Im asking this question is that
once the antenna is on the tower its a major job to pull it down again to
retune so I want to try and compensate...



Tuning Cobweb antenna

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Trimming a dipole techniques

Posted: 01 Oct 2017 11:52 AM PDT
https://forums.qrz.com/index.php?thr...niques.583119/

Im going to be putting up a simple 40m wire dipole fed with balanced
feedline so I can use it on multiple bands and wont have to worry about
feedline losses, starting out with about 68 for the cw band. My question
is, is there a way to trim it to resonance near the ground before I hoist
it into place, or do I have to just constantly lower, trim, and hoist over
and over again until its resonant? Any practical hints on this? Thank you
es 73.

Brady