Re: 1.2Ghz opperation...


Tony Gallagher <tony_g_ireland@...>
 

Ok,
So I might be able to put a low profile antenna outside. Would anyone
recomend a Wimo panel? They are about 140euros and claim a gain of
14db with a beam width of about 30degrees. Its lower profile than a
yagi so the neighbours and yl will be happy! Is there any compromise
to using a Panel antenna apart from a Yagi's gain can be much higher.

Tony




--- In ukmicrowaves@yahoogroups.com, mikeg3pfr@... wrote:


In a message dated 11/07/2008 20:12:45 GMT Standard Time,
tony_g_ireland@... writes:

Sorry if this is a silly question, but is height ASL
any advantage while working tropo?



Hi, Tony,

No it's not a silly question. It all depends!

Height can be important if you are above the tropo inversion layer,
say a
thousand feet or more. It can also be important if you have local
obstructions
- that is, within, say a couple of miles. Even then you may be able
to use
the local obstruction as a reflector, although not so much on 23cm
as on higher
bands.

Much more important is that the antenna can "see" the distant
horizon, and
maybe that's where height become more important - or just accept
that there may
be some directions in which you can't work!

Antenna height at a fixed location is always a compromise between
"seeing
the horizon" and antenna feeder losses - not important if you can
place your
gear at masthead, 'cos there's then virtually no feeder loss on
either RX or
TX.

Best advice, use 'JNT's Geog software (or other, if you have access)
and do
a "scan" of your topography out to, say 50km. That'll give you a
fair idea of
what your takeoff will be like. Then plan from that!

Regards, Mike, G3PFR

Join UKMicrowaves@groups.io to automatically receive all group messages.