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D/FW DT POWERS

B

Bob E. Nelson

Back when everything was NTSC-only, I had a reasonable understanding of power and HAAT maximums. Now that this new-fangled :) DT (err, ATSC) is finally coming to D/FW on 12 JUN 2009 (barring another deferral), I'd sure like smrat people here in this chatrum (Chip, Doug and the other usual suspects) to school me on a few things.

With NTSC, the Cedar Hill broadcasters (modulo LPTV) all had pretty much signal parity. Low-band V's at 100 kw, high band V's at 316 kw and the U's at 5 megawatts -- with fairly uniform heights for all the players.

As I check both licensed facilities and CP for DT on fcc.gov's TV Query, the power and heights are all over the place.

Case in point, WFAA-DT when it moves to RF channel 8 has a modified CP to run 45 kw at 512 meters. The app for almost-sister KFWD on RF channel 9 is for 55 kw way up at 545 meters. Another station moving their DT to V (RF channel 11) is KTVT but the FCC database shows it to be merely 23 kw at 520 meters. Looking at the DT RF facilities for those staying in the U band, it's all over the road, with some using the DT maximum of a megawatt and some with far less.

Is everything eventually going to settle in DT-wise in our market with parity or are we just a few weeks away from a brave new world with non-deterministic powers and stick heights?
 
Bob E. Nelson said:
Is everything eventually going to settle in DT-wise in our market with parity or are we just a few weeks away from a brave new world with non-deterministic powers and stick heights?
Click to expand...

In a nutshell, I choose option #2 :)

The analog power limits were 100kw/610m (chs. 2-6), 316kw/610m (chs. 7-13), and 5000kw/610m. (chs. 14-69) (maximum height was lower in some parts of the country)

For digital they're 45kw/305m (chs. 2-6), 160kw/305m (chs. 7-13), and 1000kw/365m (UHF). (maximum *power* is different in some parts of the country)

However, digital stations that arose from an existing analog station/allotment may be further limited in power due to the need to protect other stations (analog, until June 12th, and digital) from interference. There weren't enough channels available to assign everyone a channel that could be used at full 160kw/305m (chs. 7-13) power without interfering with someone else.

It's not particularly clear to me whether the FCC will allow any completely new allotments with powers limited by potential interference. (or will they only allow completely new allotments if any station using them could operate at maximum power/height without interfering?) Either way, I think we'll find existing stations will be limited to various levels (depending on specific assignment) for a very long time to come.
 
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