[Towertalk] Burning ?'s

[Rajiv Dewan, N2RD]

I used some yagi models I had on Eznec to get some quick answers.

Before I mention the results - a big caveat.
While there is some regularity in gain, f/b and boom length, number of
elements at the design frequency, there is almost none that I can
discern for off frequency behavior of highly engineered antennas.  You
really have to model the antenna you have.  With this caveat:

1.  The 5 el 20m yagi that had a free space gain of 9.84dbi and 26.7
db f/b turned 180 degrees on 17 and 12. The main lobe was off the
back, with 4 db back to front and max gain of around 3dbi.
Essentially, it sucked.

2. The pattern of 40m 2 ele yagi on 15m had huge side lobes that were
bigger than the front and back lobes.  Essentially symmetric.

Hope this helps.  Although it doubt it.

Regards,
Rajiv, N2RD

----- Original Message -----
From: "Tom Martin" <tmartin@chartermi.net>
To: <towertalk@contesting.com>
Sent: Saturday, May 25, 2002 6:02 PM
Subject: [Towertalk] Burning ?'s


> After a few hours trying to copy 40 wpm in the Worked All States
(!!!)
> contest, I decided to ask the experts on this forum a few questions.
>
> 1.  Does my 2 element 40 meter beam act as a two element 15 meter
beam
> when I use it on 15, or more as a dipole.  I have front to back and
side
> rejection when I rotate it, but is there any gain?
>
> 2.  I have been using my 5 element 20 monobander through a tuner for
12
> and 17 meters because a windom at 40 feet doesn't work very well at
all
> on these bands.  Same question.  Any gain or just a dipole with a
lot of
> aluminum around it?  Sometimes it works best aiming 180 degrees away
> from the station and I don't think it's long path.  However, I
worked
> R1MVI this a.m. at 30 degrees and a few days ago VK9KV at 170
degrees
> for the best received signal.
>
> 3. Does anyone north of Chicago hear any signals on 10 meters except
> Central America and the Caribbean?
>
> 73, Tom W8JWN
>
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>