[mythtv-users] Help setting up HD Homerun
gull at gull.us
Thu Nov 20 22:20:36 UTC 2008
> While it is strictly correct to equate total antenna gain with total
> directivity, this only holds true when we look at the polar response
> patterns in *both* the horizontal and vertical planes. Yet the latter
> nearly never really matters in practice, unless you're dealing with very
> hilly terrain or trying to shoot over the horizon on a ground reflection.
>>From the user's POV, "directional" is generally only meaningful in terms of
> the horizontal plane.
Good point, thanks for adding that.
I remember learning that after being puzzled by a 5/8-wave mobile whip
antenna, which has the apparently contradictory qualities of being
omnidirectional *and* having about 3 dBi gain. The answer, of course,
is that it isn't *really* omnidirectional -- while it radiates equally
in all compass directions, it directs very little power straight up,
which is usually a pretty useless direction unless you're trying to
uplink to a satellite. ;)
Antenna theory is fun!
More information about the mythtv-users