On this popular subject, Ialso have used the EDZ antenna for some time.
First one was 178 ft cut for 40 meters. It worked very well on all bands 10
- 80 and loaded well on 160, though too low to be very effective. Actual
length is not at all critical.
I am currently using an 88 ft version cut for 20 meters, and it also works
well on 10 - 80. It is my "main" antenna for 40 meters and does an
outstanding job.
These antennas have been fed with about 40 ft of 450-ohm ladderline coupled
through a W2DU current balun as the transition from ladderline to coax into
the shack. An MFJ 989C tuner has performed flawlessly on all bands - but, I
never run more than 100 watts and quite frequently only 5 watts for QRP
operating events.
A 44 ft version should work well on 10-40 and afford the advantage of a
single pair of lobes on those bands.
72/73, George W5YR - the Yellow Rose of Texas QRP-L 1373 NETXQRP 6
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
Amateur Radio W5YR, in the 55th year and it just keeps getting better!
Icom IC-756PRO #02121 Kachina #91900556 IC-765 #02437
John Unger wrote:
>
> A couple of months ago I modeled and built a double extended Zepp for 40 CW.
> It is about 193 feet long and is fed with 17 feet of 450 ohm ladder line. I
> connected the coax feed line through a 1:1 balun at the bottom of the ladder
> line. The antenna is about 40 feet high.
>
> Eznec 3.0 shows the impedance at the 1:1 balun feed point to be about 43 ohms
> resistance and a few J impedance. It's a 1.2:1 to 1.3:1 match for my rig at
> 7050 mHz; absolutely no need for a tuner there! The antenna has a fairly
> narrow band width, and I need the tuner for 40 SSB. I think the 2:1 SWR
> bandwidth is about 150 kHz. The Zepp loads easily on all higher frequency
> bands with my TenTec 238 tuner (had to get the TecTec plug in for this
> newsgroup somewhere...).
>
> The performance of this antenna on 40 has been spectacular; I got lots of
> glowing reports in the Virginia QSO Party and felt very LOUD. It's not
> oriented well for working Europe, but that will be a changed soon when I put
> up another one.
>
> BTW, Eznec shows that this antenna also has a ~ 1.3:1 ohm impedance when fed
> with 6" ladder line of a similar length.
>
> As always YMMV...
>
> 73 - John, W4AU
--
FAQ on WWW: http://www.contesting.com/FAQ/tentec
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
|