Mike, et.al.,
Take a look at the 3D Corner Reflector -- some call it a Trihedral
Corner. L.B.Cebik, W4RNL (sk) described this antenna at least twice.
WA4PGI, among others, has done extensive study on the thing and has
constructed and used several. Some articles are out now that describe
"shortened" or "reduced area" (my term for the same concept that was to
title the research paper I never finished) 3DCRs. I built a "reduced
area" version a dozen years ago and it still serves as my main 1296 aerial.
Compared to a Yagi of any variant, the 3DCR is a VERY forgiving antenna
in terms of pattern, performance, and impedance matching when one is
limited to simple hand tools and a "near zero" budget. The design is
easily repeatable with minimal skill/effort required. You may have
materials sufficient to construct a prototype laying around right now.
Held against a very well-constructed 15-20el yagi, a carelessly
slapped-together "ugly" 3DCR will hold its own. (field demo during June
2012 VHF 'test) It's no 2-over-2 55-loop stack laser cannon, but for
the casual op, rover, foot-portable enthusiast, etc., the 3DCR is handy
to have in the toolbox.
I added a feed for 2304 and made two bands on one aerial (w/ two
feedlines). Have contemplated mounting xvrtrs, amps and all on the
antenna itself.
73,
- Josh / KF4YLM
On 06.05.2015 11:48, Zack Widup wrote:
The most critical elements are the reflector, driven element and first
director. The driven element is the one that has to be built to take the
power.
As I noted, you can saw off (or construct a shortened version of) the loop
Yagi with as few as half a dozen elements. You can probably do this with
other types of Yagis, too. Since it's not going to be used for long-haul
work, I'm assuming you're not wanting to optimize it much for gain, etc. I
think the 24 element version cost me all of about $40 to build. A shorter
one might cost $15-20 to build.
$250 seems like a lot of money for that one.
:-)
73, Zack W9SZ
On Wed, May 6, 2015 at 10:40 AM, Patrick Barthelow <apolloeme@gmail.com>
wrote:
If you build a homebrew yagi at 1296, from simple materials, Al welding
rod, or copper #12 guage, and a wooden boom, perhaps a hardwood meter
stick, what is the most touchy dimension or other aspect of the build that
you have to get just right to achieve max gain? What component,
establishes a max power rating of say, 100 watts, vs a desired KW max
power?
On Wed, May 6, 2015 at 8:14 AM, Jerry <jer.sieg@shaw.ca> wrote:
That's a lil pricey ! Mike, if your just looking for a cheap yagi..
check
out E Bay for the Chinese stuff..
http://www.ebay.ca/itm/281126325870?_trksid=p2055119.m1438.l2648&ssPageName=STRK%3AMEBIDX%3AIT
$20 and usually Free Shipping ! Can't beat that price if you just want
to
'play around' a bit ! 73
Jerry
VE6CPP
On 5/6/2015 14:49, Mike (KA5CVH) Urich wrote:
Soooo, I'm looking at possible antennas for my ID-1. I'd like a small
~4-6 el yagi just to point towards the repeaters downtown, <or a
monoband omni>. I may build me a "cheap yagi" but I wanted to see
what else was available. I stumble across this one ....
http://www.antennasystems.com/product/antennas-af-yagi-1-1_3-ghz/YA1200-9_5-6.html
I wish them luck with that.
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Best, Pat Barthelow
AA6EG
apol <apolloeme@gmail.com>loeme@gmail.com
Google Lunar X prize Team, SYNERGY MOON
www.syner <http://wwww.synergymoon.com>gymoon.com
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