--- In Repeater-Builder@yahoogroups.com, "Yahoo" <[EMAIL PROTECTED]> wrote:
>
> There are a number of old post on this subject. Take a look at the
4 bay
> dipole antennas from Antenex (made by Bluewave). VERY broadband.
As for
> whether or not they are expensive is a matter of personal opinion.
>
> Jeff
>
> -----Original Message-----
> From: Repeater-Builder@yahoogroups.com
> [mailto:[EMAIL PROTECTED] On Behalf Of Jed Barton
> Sent: Thursday, February 15, 2007 12:14 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Antennas that work both in commercial
and
> amateur
>
> Hey guys,
> I need some suggestions. I need a vhf and a uhf antena.
> Here's the requirement. I'm planning to operate both amateur and
commercial
> stuff from the house.
> I'd rather not use a ham antenna in the commercial bands.
> Are there some that'll do the 136 to 174 split, and some UHF
that'll do like
> 439 to 490?
> Any ideas?
>
> Thanks,
> Jed
>
I've been watching this topic and cannot recommend the half
wave dipole bay antennas as not really efficient gain wise for what
one gets for the effort..
The Station Master series has been mentioned, which has good
omnidirectional gain, in the order of some 10 db, and which is equal
to having a 10 element beam in all directions!! Far above a 4
section dipole arrangment!
The Station Master series is made of stacked coaxial sections inside
the fiberglass. Unsolder the wire from the top metal cap and
unscrew the cap and look inside. First you will find that there is
a quarter wave element at the top, then phased half wave coax
sections below that. Research staked Coaxial vertal antennas on the
Internet, they're well covered. I favor them as out performing most
anythinb else.
Gonset discovered back in the 1960's era that the bandwidth aspect
of a halfwave antenna was the results of the ratio of the thickness
of the half wave antenna to the half wave length, and reinvented
the "bow tie" antenna, typically used for broadband TV!!!
Hahahahaha!!!
It also depends on the radiation pattern, where it goes and how
narrow it is. I've had a single section coaxial vertical antenna,
basically a half wave vertical, mounted at ground level, out perform
a mobile 5/8th wave 3 db gain vertical, mounted on my vehicle out in
the driveway, with the same radio, but a few feet higher!! The
mobile 5/8th wave puts out a very narrow pattern at horizon level,
and the coaxial a wider donut shaped pattern also at the horizon..
While I think it said that the proposed antenna is to be on top of a
building, the same antenna on a mountain top repeater has to do the
same job in the weather, and over time, whether it's an Amateur
Radio or Commercial installation..!!!
Best,
Dick
