[kwlug-disc] Home made indoor TV Antenna

[John Johnson]

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.

Agree.
 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 
avoided.

These discussions remind of this Mr Bean skit (a classic): 
http://www.youtube.com/watch?v=Sm3_qEMTdc4

JohnJ