On Sat, 16 Feb 2013 19:57:44 -0800, Jeff Liebermann
wrote:

With an 8 foot boom, you'll probably fit 9 elements:
http://www.vk5dj.com/yagi.html
13dBi gain, 44 degree beamwidth.

Here's another yagi calculator program:
http://www.yagicad.com/YagiCAD/YagiCAD.htm
It will do a variety of driven elements and yagi styles. It also
exports results to 4NEC2.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 2/17/2013 12:24 AM, Jeff Liebermann wrote:
On Sat, 16 Feb 2013 19:57:44 -0800, Jeff Liebermann
wrote:

With an 8 foot boom, you'll probably fit 9 elements:
http://www.vk5dj.com/yagi.html
13dBi gain, 44 degree beamwidth.

Here's another yagi calculator program:
http://www.yagicad.com/YagiCAD/YagiCAD.htm
It will do a variety of driven elements and yagi styles. It also
exports results to 4NEC2.



My calculation, based on a database of 100+ EME antennas predicts 13.6
dBi maximum reasonable gain. So that sounds about right.

tom
K0TAR

On 2/17/2013 7:51 PM, tom wrote:

My calculation, based on a database of 100+ EME antennas predicts 13.6
dBi maximum reasonable gain. So that sounds about right.

tom
K0TAR


Here is a link to a table of a lot of high performance yagis.

http://www.sm2cew.com/gt.htm

tom
K0TAR

"tom" wrote in message
. ..
On 2/17/2013 7:51 PM, tom wrote:

My calculation, based on a database of 100+ EME antennas predicts 13.6
dBi maximum reasonable gain. So that sounds about right.

tom
K0TAR


Here is a link to a table of a lot of high performance yagis.

http://www.sm2cew.com/gt.htm

tom
K0TAR



Thank you all for your thoughtful comments. I like the downspout idea. (I
was going to coat the wood boom with good epoxy paint, but, considering also
the weight issue, maybe I should go with the downspout. It's going on a
chimney mount, not a tower, making maintenance a bit simpler.)

I saw the T-match but never intended to try it. I did get my gamma match to
a 1.2:1 VSWR so, now I'm undecided.

I used to use YAGICAD running under a BASIC interpreter, I think, but a
lo-o-ong time ago. I will have a fresh look at it.

I thought after the first four or five directors were in place, their
spacing wouldn't be affected by adding more directors. Thanks for the
heads-up that it matters.

"Sal"