[ale] HDTV antenna for urban areas

[Jim Kinney]

That looks like a wind loading problem to me :-) !! Air velocity
parallel to wave vector = new aim point is vertical

extra points for new materials costing under $30 total!

time to cook up a yagi in a chunk of sheetmetal ducting.

I'm still using just a half-wave dipole (tuned for channel 2) cooked
up from a chunk of 1/2" pvc pipe with a bare 12G copper folded loop
cable tied and hot glued in place. $2 balun connects to really crappy
RG58 coax. I could get MUCH better reception if I put it in my attic
away from the masonry chimney and out from behind a layer of brick
wall.

But I'm still waiting for some thing to watch... maybe I'll actually
catch MI5 this week.

On Tue, Jun 2, 2009 at 9:48 PM, Daniel Howard<dhhoward at comcast.net> wrote:
> As a small token of my appreciation to the list, and since some folks
> have posted recently about setting up off air HDTV reception with the
> transition date looming, I thought you guys would enjoy some solutions
> I've run across for dealing with the extensive multipath you get in
> dense urban areas for HDTV reception.  Enjoy, Daniel
>
> 1.  My solution: I have two RadioShack large aperture/gain antennas in
> my attic, each with a low noise amp at the antenna output, and I have an
> A/B switch in my TV room such that when I see multipath interfering with
> reception on one antenna, I switch to the other.  The antennas have to
> be at least 10 lambda apart however since their gain is so high, and at
> VHF frequencies for Channel 11 (around 200 MHz), this is about 48 ft.,
> Using a spectrum analyzer revealed the multipath was spatially
> decorrelated between the two antennas in my attic even though they were
> only 40 ft. apart.
>
> I had to use this solution because I'm in a valley topographically with
> buildings and land blocking my direct line of sight to the antenna
> towers.
>
> 2.  If you have line of sight to the towers (use www.antennaweb.org),
> but have lots of big buildings around you, you just need a really
> directional antenna, here's what my friend at GaTech used.  Make sure to
> click page two at the bottom of the web site for the second, more robust
> and easier to manufacture solution that he came up with, brilliant IMHO.
>
> http://www.prism.gatech.edu/~wn17/
>
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>



-- 
-- 
James P. Kinney III
Actively in pursuit of Life, Liberty and Happiness