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Antenna for 10m contest

Mar 4th, 13:16

K1BBB

Joined: May 8th 2013, 22:09
Total Topics: 0
Total Posts: 0
I plan to participate in: http://www.nauryz-dx-contest.com/ from Indiana.

I'm really new to Amateur Radio, but feel like I had some success last weekend during the contest, making contact with 17 different countries. And I found it rather enjoyable. I found the Nauryz contest on QRZ.com and thought I'd give my hand at it. Here are my questions.

I have an Icom IC-761 (seems to have a great autotuner) and it's 100W. Currently I have a handmade 10m dipole with what I believe to be propagation from East to West. During last weekend's contest, I was getting South America, Alaska, as well as Europe and Eastern Europe (Ukraine, Bosnia, etc..) This worked well for a general coverage antenna I think. But since this Nauryz contest is located in one central area, I suppose that I'll need a more direct method to make as many contacts as possible.

What kind of simple homemade antenna, might work best for this? I should also note that I do not have a way to turn the antenna remotely, and would probably get up on the roof to adjust it by hand. I plan to do this the few weeks prior to the contest, and hope to get it in the correct direction.

I currently have easy access to some cheap supplies at a hardware store (say Lowes or Menards). Wood, PVC pipe, and wire that is available at those sorts of locations, are what I could feasibly get. Of course, I also have Radio Shack available as well. I do have an extra 50' PL-259 to use for this.

So far, I've read a little about Moxon, Loop, Dipole, and Yagi antennas, and they seem to all have their fanboys. Yagi seems to be a little too much for me to build and work with for now, so I kind of discounted that already. Moxon and Loop seem reasonable in price, but I'm unsure how well they would work with my Icom-761, so comments on this would be great. Plus if you guys have any other suggestions for antenna types, please let me know.

Thanks!
-Matthew, KC9ZFI
Mar 4th, 14:42

W1VT

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

Central Asia can be a difficult place to contact with just 100 watts and a simple antenna. From Indiana, you have a "Polar Path." Polar Paths are challenging for DXers--your signal is likely to be blocked by the auroral curtain. A K index of 3 or higher typically means no propagation. I'd be happy with just one or two contacts--just as I was in the EME contest, where I made two QSOs and got a great looking participation pin!

http://www.voacap.com/
http://www.voacap.com/prediction.html
I'd suggest running this propagation program for both Long and Short paths--you will find your propagation windows to be quite short.

Yes, a Yagi is typically best, but on a path like this, where you want to work both long and short paths, a bidirectional wire beam may be better.

A High Gain Single Wire Beam by Robert Wilson, AL7KK
QST July 2009, pp 38-39
The author now recommends feeding this antenna directly with a 4:1 balun instead of the shunt inductor arrangement suggested in the article.
http://www.arrl.org/files/file/protected/Group/Members/Technology/tis/info/pdf/QST_Jul_2009_p38-39.pdf

On the East Coast, the difference between magnetic North and true North is almost 14 degrees, so we need to account for that when using a compass to set the beam heading. It is likely that you don't need to worry about that where you live. A good reference for North in much of the USA is Polaris, the pole star--though it doesn't work as well as you get closer to the equator.

Zack Lau W1VT
ARRL Senior Lab Engineer


Mar 4th, 16:19

K1BBB

Joined: May 8th 2013, 22:09
Total Topics: 0
Total Posts: 0
Wow, awesome information! I played around with voacap, and I have to say I'm impressed. I'm going to have to use this more often. Though, I do feel almost like I need a training session for it, I do mostly understand what I'm doing with it.

That's certainly an interesting antenna design. I'm going to have to consider it.

Thanks again Zack.

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