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

[Craig Treleaven]

At 4:22 PM -0400 8/21/09, Colin McGregor wrote:
>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...
>

I think Brian has overstated the difficulties, somewhat.  DigitalHomeCanada has an excellent FAQ on the subject and quite a number of the members there use two (or more!) antennas. 

Nonetheless, I'd recommend you get one better antenna.  Many folks in the GTA have good results with the Channel Master 4221HD, 4228HD (even better with the older 4221 and 4228, if you can find them).  (DHC has some very simple hacks that improve the HD versions as well.) 

A lower cost alternative is to build a Gray-Hoverman variant.  An online community has designed a very high-performing antenna that can be built for a few bucks.  Again, DHC has the plans but they are also elsewhere on the net.


Craig