[kwlug-disc] Home made indoor TV Antenna
jvj at golden.net
Fri Mar 14 13:35:30 EDT 2014
On 2014-03-14 12:52, unsolicited wrote:
> Careful with that - one of the things I repeatedly saw in my reading
> is that CKCO is so strong it overwhelms everything else. Amplification
> will only make it worse.
From reading not doing: Due to poor results, long ago, I have not
experimented with antennas, homemade or other, in a long, long time.
> Also from my reading, there are really only two directions that matter
> here, towards the CN tower, and towards Buffalo. So I saw two
> approaches - dual antennas combined together, one pointed each way,
> and a single antenna pointed in the middle - level of success seemed
> to depend upon one's elevation.
In the analog, VHF and UHF worlds multiple antennas, unless switched in
and out, can cause a phenomenon known as multipath or, more commonly,
ghosting. This caused by one antenna picking up a signal traveling
directly from a transmitter and the other picking up a signal, from the
same transmitter but which has been "bounced" around a bit, e.g.
reflected from buildings or hills. The different signals have traveled
different paths to reach the receiver and the different paths have
different transit times causing the ghosting.
I simply do not know how HDTV aka ATSC tuners handle multipath.
There are many reasons for the use of rotators, one of which is to avoid
multipath caused by the use of multiple antennas.
Caution: The wires or cable used to transport the signal form the
antenna to the receiver should be designed for RF. And, if used, the
switches used to switch between multiple antennas should also be
designed for RF. Garden variety wires, cables and switches should be
These discussions remind of this Mr Bean skit (a classic):
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