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Antenna Polarization for FM contesting

May 3rd 2014, 23:01

Gringo6

Joined: Mar 20th 2014, 18:00
Total Topics: 0
Total Posts: 0
For best results in the FM only single operator contest should I stick with vertical polarization or go to horizontal polarization ?

K5HWS
May 5th 2014, 20:42

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0

You should stick with vertical polarization.

I've done FM contesting using 222 and 446 Yagis mounted on a horizontal crossboom.
I've designed a rear mount 2M FM Yagi.

Jun 2012 - QST (Pg. 39)
An Easy to Build Rear Mount 2 Meter Yagi
(Feature) Author: Lau, Zack, W1VT

Zack W1VT
ARRL Senior Lab Engineer
Nov 2nd 2014, 22:08

WD3D

Joined: Mar 1st 2011, 09:28
Total Topics: 0
Total Posts: 0
Actually, I would have to disagree.
Most contests are held away from the FM crowd on Single Side Band.
You will be hard pressed to find anyone to work during a contest, since most contest stations uses horizontally polarized - beam antenna's, and they use Single Side Band frequencies.
Their antenna's are not designed to operate in the FM portion of the bands. If you already have a 13 element - 2 meter FM beam antenna, and if it is already vertically polarized, then it is what it is, and it isn't going to make any difference if you are going to make contacts more then 80 miles away - since the polarization changes when the signal travels over the horizon.
The key is to purchase a good 2 meter / 70 CM - Single Side band transceiver, even if it is just a mobile - as long as it does Single Side Band.
In the morning, it is possible to work people as far north as Detroit Mich from Western Pennsylvania on 2 meters with just a single 13 element beam on a 60' tower, at an elevation of more than 1300' and some decent coax - Belden 9913 or LMR 400 and some good UHF (N) - not PL connectors. PL connectors are no good for frequencies above 250 MHz. They are just too lossy, as is cheap coax. Your best bet is to get a 6 meter beam antenna and work 6 meters SSB...
Nov 4th 2014, 13:52

WB1GCM

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
If FM is all you have, FM polarization is fine.

I appreciate FM operators during VHF QSO parties. FM contacts added to my overall score, each time I have participated. During lulls in the event, I always check out the 2 meter FM simplex frequencies (excluding 146.520 MHz). Those 20 or so extra QSOs can add to a serious contester's score.

It would be nice to see some new participants during contests. Maybe we should have an FM only catagory?
Nov 6th 2014, 19:39

w1rfi

Super Moderator

Joined: Apr 4th 1998, 00:00
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Total Posts: 0
In one of the VHF contests, I did a bit of roving and I had a lot of fun getting on FM simplex between roving sites and working the hams on simplex. Many had modest antennas and were delighted to have some fresh meat. I think we are seeing more FM activity in contests than in years past and I will add some fun to the contest. Ed, W1RFI
Jun 26th, 03:04

WD3D

Joined: Mar 1st 2011, 09:28
Total Topics: 0
Total Posts: 0
There is no such thing as an FM antenna as far as polarization goes.
SSB 2 meter antennas are all horizontally polarized because the boom is extremely long. The weight of the antenna could not be supported by the boom - hence when it is mounted horizontally it is structurally stronger than horizontal - where the wind would grab it like an airfoil and bend it.
Since the rules has changed to allow FM on the main VHF contests, there are operators that has little equipment, but would like to operate, hence you use what you have.
Once the signals pass over the horizon, the polarization of the signal is of little consequence.
You would benefit more to have your vehicle parked at the top of a mountain and a mobile whip antenna then to be down in a valley or behind a hill with a 1000 watt amplifier and a 48' foot boom beam antenna.
6 meters is the one exception.
When the band opens you can use anything ( dipole, beam, Moxon ) at any height and make multiple contacts with even a low power transceiver and some crappy coax.

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