Originally Posted by Jams
Well I was a little off. The spread of the DTV channels is less than 90 degrees so it seems if he pointed the squareshooter in the middle of them it's only looking just less than 45 degrees left or right for the signal.
I did not know that by removing the back screen from teh bowtie antenna that it would make it a bidirectional thing but since we're at just less than a 90 degree split would that really work? I don't think two antennas is a choice.
What about the clip on ones that terk and phillips make? They seem to be omnidirectional and since he's so close as long as it's up high enough I think that would work. Plus they have the built in dual diplexer which is good for him. He's not yet ready to run another line into the house.
Here is some info on antennas with wide beamwidths:
W-G SquareShooter: SS-1000 (no Preamp) or SS-2000 (with Preamp)http://www.winegard.com/offair/s2shooter/WC-811.pdf
When I blow up the scale, I see that it uses a field polar plot (volts/meter),
rather than the usual dB scale.
So 3 dB down is at 0.707, i.e. 20*log(0.707) and 6 dB down is at 0.5.
At +/- 90 degrees, it's down about 5 dB from maximum gain for low channels,
and about 8 dB for upper channels.
W-G says the average UHF gain is about 4.5 dB, so you have about -0.5 to -3.5 dBd gain
in two desired directions and about 4.5 dBd gain in undesired direction.
Fol. is NEC Simulation for SquareShooter:http://www.hdtvprimer.com/ANTENNAS/SquareShooter.html
It shows that +/- 45 degrees is about 6 dB down on the sidelobes.
W-G Sensar III: GS-1100 (no Preamp) or GS-2200 (with Preamp) is much lower cost.http://www.solidsignal.com/manuals/WC-810.pdf
Note that at VHF it is bi-directional, whereas at UHF it is unidirectional.
This is also a field polar plot (volts/meter) rather than the usual dB scale.
At +/- 90 degrees, it's down about 5 dB from maximum gain
(give or take a little due to the skewed response and pointing inaccuracies.
W-G doesn't say what the maximum gain is, but it must be less than 3 dBd.
So the net gain is -2 dBd in desired directions and + 3dBd in undesired.
Gee, they don't say much...but antenna pattern is probably similiar to Sensar III.
Either of these antennas are much lower cost alternative to the SquareShooter
and all will perform about the same.
Note that omnidirectional antennas (e.g. W-G MS-2000 MetroStar and MX1405 Maxus)
will have about 0 dBd gain in all directions, but do not provide suppression of multipath in any direction.
Suppression of multipath being reflected into the "back" side of the antenna is highly desirable.