Those gain numbers are totally unrealistic.
A good 5L monobander on a 0.75 WL boom can achieve 10.5 dBi.
It takes 6L on 0.8 WL boom to reach 11 dBi. 7L on a 1.4 WL boom
can reach 12.2 dBi. See Table 2.4 on page 2-22 of the W2PV
"Yagi Antenna Design" Book.
If those numbers include the 6 dB ground reflection gain, then the
antenna would have less gain than a set of 2L monobanders.
Either way, the numbers make no sense, but back then
most antenna gain numbers came from the Advertising
Department, not the Engineering Department, and almost
no one could verify them.
de Tom N4KG
On Tue, 21 Dec 1999 22:21:26 -0500 Masahiro Miura <firstname.lastname@example.org>
> Creatibe Design Corp 318C
> 20m: 4 element 11.0 dBi
> 15m: 5 element 13.0 dBi
> 10m: 5 element 13.2 dBi
> boom length: 9.1m
> element length: 8.7m
> weight: 26.0kg
> wind area: 1.0 square m
> Creative Design Corp.
> 4-8 Asano-cho
> Kawasaki-ku, Kawasaki City
> 210-0854 Japan
> Email: email@example.com
> Phone: 81-44-333-6681
> Fax: 81-44-333-6598
> Date: Mon, 20 Dec 1999 13:05:19 -0500
> From: firstname.lastname@example.org
> Subject: Re: [TowerTalk] Create CD318C Antenna - Information Please?
> Create was made in Japan. I had a Create 80/75 single element sold
> by a
> firm out of California. He went of the business
> about 10 years ago. Have not heard of Create since.
> Dave K4JRB
> > Does anyone have any information on the Create CD318C antenna.
> I've done a
> > search of the WWW, but doesn't produce much joy. I believe that it
> is a 6
> > element 20/15/10 tri-bander, but know no more. Anyone with boom
> > element configuration, wind load data etc. Even better - anyone
> with any
> > experience.
> > Thanks,
> > 73,
> > Andy Cook, G4PIQ
> > email@example.com
> Masahiro Miura, AJ3M
> Bethesda, MD
> Phone/Fax (home): 301-320-7787, Phone (work): 202-458-5814
> Email: AJ3M@arrl.net, AJ3M@oursquare.com,
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