[TenTec] Antenna Help

[Rick - DJ0IP / NJ0IP]

Don's reply to the request for Antenna Help is EXCELLENT.
Clearly he has had a lot of experience.

I would like to comment on two of his points - Balun and the bungee.

First the BUNGEE:
Living in Oklahoma from 2007 thru 2010, my antennas were subject to a lot of
UV.
I did not do as Don recommended.  I used local bungee cords purchased at the
local Walmart.
I had to replace them every year.  The WX and UV destroyed them within a
year.
Sounds like Don knows something I didn't.  Next time I do this I will
certainly try real rubber bungees.

Now the BALUN:
I am going to use an example to challenge Don's response to this, though he
was not exactly wrong.

***Recently a soccer mom asked me what would be a good car to haul the
neighborhood boys to the soccer practice.  I replied with 'many soccer moms
seem to be satisfied with a Chrysler'.  So she bought a Chrysler Crossfire.
- I was thinking Voyager or Town and Country.  She followed my advice but
got it totally wrong.***

It is EXACTLY the same with baluns.
Although DX-Engineering, Balun Designs, and Comtek all make good quality
baluns, it is possible to buy one of these and make exactly the same mistake
described above with the Chrysler.

These companies make as many different type of baluns as Chrysler makes
different types of cars.
In many cases, only one of their models is the right one.
BUYER BEWARE!  Otherwise you might end up with a good implementation of the
wrong technology!

73 - Rick, DJ0IP
(Nr. Frankfurt am Main)


-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Greg S via
TenTec
Sent: Tuesday, December 30, 2014 11:23 PM
To: tentec at contesting.com
Subject: Re: [TenTec] Antenna Help

>From my experience- - the 80M Skyloop is the best "near-in" antenna you
will find for 30M-80M. It becomes more of a DX antenna, the higher you go in
frequency, due to lower take-off angles. Some nulls and peaks, but at that
distance, it doesn't seem to matter much.... they get filled in. Again- FROM
MY EXPERIENCE:

- What kind of wire should I use for the loop antenna; 14-16 Ga stranded,
insulated wire. Copper.

- What type of rope that will hold up to the UV and time (so much just falls
apart these days): Buy a roll of string trimmer line. Mine has been up over
5 years, with nary a break. Buy  GOOD, REAL RUBBER bungee cords, and use
them at the connection to the loop antenna.  Stress relief. Do this no
matter what wire/rope combo you use.

- What balun, 4:1, 1:1 ?: 1:1... a GOOD one. Comtek, Balun Designs, DX
engineering.... there may be others.

- Is 450 ohm feed ladder line the best to use? This part will be about 80
feet long. Will this length be a problem?: It will work fine. I prefer the
600 Ohm true LAdder line, that was originally made by W7FG. Search, you will
find it. The 450 Ohm will show some change in matching when it is wet, snowy
or icy. Not a big deal. Make a nice, rugged stress relief coupling at the
antenna feed point. Strap the feed line to the balun rigidly so it does not
flex at connection. Waterproof them with lotsa goop.

- Has anyone ever had any issues using
delrin for the insulators? Is there a better?: Yes, UHMW plastic. Delrin
will get brittle from UV over the years. If you must use Acetyl, get glass
filled.

- I am thinking about placing a screen door spring on each corner to allow
the trees to sway in the wind? anyone ever tried that. Or should I just
counter weight to opposing corners of the loop?: See above about GOOD RUBBER
bungees.

- How?s the best way to protect this
setup from lightning?: Don't ground anything in the shack. If it's not
grounded, why would lightning wanna hit it? (THINK about it).

Thanks in advance for any help!: Welcome. Greg, KC8HXO



73

Don kb3drw

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