On 5/10/2011 11:42 AM, Tom Rutherford wrote:
"Jim wrote in message
...
On 5/8/2011 10:22 AM, Tom Rutherford wrote:
wrote in message
...
http://search.yahoo.com/search;_ylt=...20meter%20halo
Myself I'd probably stick a small 3 el yagi on that
lamp mast if you had room..
Good bit more punch for SSB, and being things are
reciprocal, it will improve reception. If you squeeze
an extra 6 db from the antenna system, that's like
taking 50 watts and turning it to 200.
Best deal on an "amp" you will find..
I'm not sure the gain using a halo, but I suspect
it's probably pretty close to a dipole. Maybe a tad
more, but it's not going to be a drastic difference.
A loop has some gain broadside vs a dipole, but I'm
not sure what you get running one on it's side.
Thanks much. I'll have a look at that link and see what's what. The
Yagi
would be nice, but running out on the balcony and moving it around all
the
time isn't practical. That's why I wanted something fairly
omnidirectional,
as much of "omni" as I can get, anyway. Since I remember what my
communications instructor told us about loops (they radiate equally
poorly
in all directionsg), I figured this would be the most practical
solution
for what I want to do.
A horizontal dipole in front of a screen or single reflector would have a
"pattern" that is 100+ degrees wide.
How far behind the driven element should the reflector be? A quarter
wavelength?
You got it.
Stack a couple vertically, say a meter apart, and you squeeze the vertical
beam width significantly, which is probably what you want.
Hmmm...! :-) That might be interesting, too. Feed them 90º out of phase?
Feed them in phase.
What you *might* want to do is look for a low gain TV antenna for the
upper VHF bands (e.g. Channel 7-13): one of those two bay things with a
bowtie in front of a screen.
Think I'd need some kind of a balun to get the impedences to match?
Maybe.. depends on the antenna.
But consider that they might actually have a 75 ohm impedance, which
will be close to what you need.