[mythtv-users] Semi-OT - Dual TV antennas

[Colin McGregor]

On 8/21/09, Brian Wood <beww at beww.org> wrote:
> On Friday 21 August 2009 13:14:40 Colin McGregor wrote:
>> Up until now I have been using one Winegard GS-2200 antenna on my roof
>> to provide an over the air TV signal for my MythTV box. This has
>> worked okay, but I am wondering ... as I have a second identical
>> GS-2200:
>>
>> - Would there be an advantage to setting up a 2nd GS-2200 antenna?
>> - The GS-2200 is an amplified antenna (using a small power brick in
>> the attic), does that brick provide enough power to support 2
>> antennas?
>
> Are you planning to combine the two antennas? Or are you planning to use
> them
> as seperate sources (perhaps one antenna to each of two cards)?

I had hoped to combine the two antennas for better reception. Ironic
that there is a TV station only a handful of miles from me (CITY-TV)
that I can not get reliably (granted there is a bunch of tall
buildings between me and the transmitter. Still, I get the Buffalo, NY
PBS station almost rock solid 24/7 with those same buildings between
me me and that transmitter (yes, I know CITY-TV uses a (far?) lower
power transmitter, still)...

Bottom line I would love to get more of the local stations, more
reliably and without being out the cost of a new antenna...

> The problem with combining the two antennas is phase - unless the signals
> are
> perfectly in phase you will get some cancellation and other problems, which
> will vary by channel.
>
> Combining the antennas is likely to cause more trouble than it cures, unless
> the spacing is perfect, and you use a proper phasing harness, and even then
> it would only work properly on a single channel.

This is the sort of thing I was afraid of...

Thanks.

> There are other things you can do with a second antenna, if you have a
> severe
> reflection you could use point the second antenna off-axis to point at the
> major reflection, invert the phase and use that signal to help cancel out
> the
> reflection.
>
> As for your question, I'd have to know what the power draw of the amplifiers
> was, and the rating of the power supply, but I'd guess that you probably
> could power two amps from the power brick, those amplifiers donot draw much
> power.
>
> --
> Brian Wood
> beww at beww.org

Colin McGregor