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Re: [TowerTalk] New TV antennas

To: "Tower Talk List" <towertalk@contesting.com>
Subject: Re: [TowerTalk] New TV antennas
From: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 16 May 2009 09:38:57 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On Sat, 16 May 2009 04:01:22 -0400, Roger (K8RI) wrote:

>Even here in Michigan we will have at least two active digital stations 
>on Ch 2.  Nation wide I believe there will be on the order of 20-30. 

That is not accurate. Most broadcasters are abondoning Ch 2-6 channels 
because, during the first years of DTV, they learned that the impulse noise 
in this frequency range seriously degrades DTV performance. WBBM, the CBS-
owned station in Chicago, was assigned Ch 3. It was a train wreck, and they 
are moving to Ch 12 with the transition. (They can't go there yet -- 
there's an analog Ch 12 in Milwaukee). 

Your part of Michigan is a bit of an exception to the national trend -- 
several stations will still be on VHF, and WGVK will be on Ch 5. A search 
of the FCC database lists a total of 7 DT licenses for channel 2 in the 
entire US, including those currently on the air. WWMT is the only one 
currently on Ch 2 in MI, and they are moving to Ch 8. After the transition, 
you will have stations on 5, 7, 8, 11, 13. The rest will be on UHF. 

It's an interesting trade-off between reduced attenuation on the lower 
channels and the impulse noise problem. In general, when stations have the 
choice of a high-band VHF assignment or UHF, high band VHF is preferred. 

To see details, check out the FCC map book of coverages and channel 
assignments at

http://www.fcc.gov/dtv/markets/

Note that some of these coverages are fictional, because they do not 
consider terrain, and they assume 10 dB of antenna gain at 30 ft. 

Another very useful link is the master FCC database search page for AM, FM, 
and TV broadcast licenses. To search TV, click on TV query. To search your 
area, plug in your lat/lon coordinates and select a radius in km. 

http://www.fcc.gov/mb/audio/

73,

Jim Brown K9YC



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