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Antron99 on HF

Oct 10th 2011, 05:11

WA8OCL

Joined: Feb 1st 2011, 09:05
Total Topics: 0
Total Posts: 0
Hey Guys. I'm putting up an Antron 99 for 10 ~ 17 meters.as I am on a fixed income and have very limited space.
I had planned on adding the GPK1 radial kit but a fellow ham told me not to waste my money. According to him I should rap my coax 10 turns around a one pound coffee can about 2 feet below the antenna, and that would decouple the coax from radiating.

Now I was always told that doing something like that would create an RF coil which can change the impedance
or the inductance.

Any advice on this matter from our varied and intelligent experts would be greatly appreciated.

Coax = RG-8X @ 85 feet.
Antenna = Antron 99 @ 55 feet
Radio = Yaesu FT-757GX
Power = 125 Watts max

73 Pat McLain WA8OCL
Oct 11th 2011, 06:47

KE8DO

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Hello Pat
I have not heard of an Antron 99 antenna, but I assume that it is a vertical. To work right, a vertical antenna needs radials connected to the coax shield, or at least a ground rod or some kind of ground. You can save money by using electric fence wire from a farm supply store or what ever old wire you happen to have for the radials. I would also make a choke with the coax, as your friend suggested. At that frequency, you may be able to get by with less than 10 turns.
Can you tell us more about the antenna? Is it ground mounted?
73 Don KE8DO
Oct 15th 2011, 10:13

WA8OCL

Joined: Feb 1st 2011, 09:05
Total Topics: 0
Total Posts: 0
Here are the specs on the antron 99:

The Solarcon A99 is a half wave over a quarter wave variable mutual inductance antenna for 10 to 17 meters. It features the Solarcon twin ring Adjust-A-Match system to obtain the optimum SWR. Simply raise the rings to raise the frequency or lower the rings to lower the resonant frequency.

The rugged three-piece white fiberglass construction features triple plated brass fittings.

This antenna is 17.75 feet (5.5 m) high. It has 3 dBi gain and the power limit is 2000 watts. Accepts PL-259 and mounts on a 1.5 inch mast (not supplied).

There is also an optional GPKT Ground Radial Kit available for improved performance.

The 10 turns of the coax is supposed to replace the GPKT Kit for decoupling the coax to keep it from radiating.
Oct 21st 2011, 22:47

SIZE358

Joined: Apr 19th 2009, 19:30
Total Topics: 0
Total Posts: 0
spend a little more and put up the i max 2000 it is the big brother to the a99 i have both antennas the imax works a lot better and is 6ft taller.....73
Oct 22nd 2011, 01:06

KM3F

Joined: Mar 6th 2008, 13:50
Total Topics: 0
Total Posts: 0
Something that needs to be said about the balun coil vs the radials.
While the balun coil will decouple the feed line in ''the absence" of the radials, the radials helps lower the radiation angle and improve gain, important for DX or low angle performance.
Often advice, while meant to be helpfull, often is not complete enough.
Radial length is longer for 17 m vs 10 or 12 m.
To be fully effective the antenna's tuning should be optimized for the band in use.
Using a tuner does not make up for this.
It only transforms the feedline impedence seen to 50 ohms for the radio to output it's max power that may still not all be radiated as desired.
Good luck.
Oct 27th 2011, 23:23

KG4MAV

Joined: Jan 11th 1999, 00:00
Total Topics: 0
Total Posts: 0
I'm going to put my 2 cents in here. I also am on disability with very little left at the end of a month. I went to a farm store and bought a roll of their electric fence wire. I think it was a miles worth for cheap! I have used that stuff for a long while making dipoles and also using it for ground radials. The ground radials are all 1/4 wave of the frequency. I got a used Butternut HF9V at our local hamfest and when I put it up I laid down 1/4 wave radials for each band from 6 to 80 meters. All of them were laid on the ground after mowing the grass real short. I have had no problem with the mower vs. wires. The more wires the better the signal up to a point. Are you going to ground mount this? Or put it in the air?
73
Russ Abbey
KG4MAV

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