[mikemikeb]

Why? The economy is too strained now. The penetration rate of over-the-air is maybe 15-20%, the rest using cable or satellite. People with cable or sat won't care about lower power levels, but the station operators would care about lower power costs. Of those with OTA, most of them are closer to the transmitter; for them, lower power levels mean reduced or eliminated wind-related multipath intereference. Super-long-range OTA viewers are usually not lucrative enough for advertising, anyway, to spend the extra dough on transmitting costs. So it's a win-win-win for broadcasters.


So, stations should reduce their power levels to more manageable levels, in the 150-400 kW range for UHF. Maybe 500 kW in areas with high OTA penetration throughout a very large DMA, like Houston.


Here's an example: In Washington, DC, there are two UHF digital TV stations broadcast from the same tower site: WRC, at 813 kW, and WFDC, at 325 kW, both omnidirectional. Where I live, WRC is usually plagued with multipath interference in even mild wind, however I seem to orient the antenna, yet WFDC is very stable. But look at the TVFool coverage areas of both WRC and WFDC . They look shockingly similar at longer ranges, which is especially interesting, considering that WRC's antenna is 40% higher than WFDC's (242 vs. 173 meters above average terrain). If someone can get WRC-DT with an antenna, chances are they could pull in enough signal to lock WFDC-DT, especially if the WFDC antenna were as high as WRC's.


On a related note: Lower power levels open UHF stations up to solid-state transmitter technology that's getting more power-efficient per watt of TPO than ever. By next NAB show, I'd think that there would be new transmitters that incorporate new technology that further improves solid-state technology. The concept of selling a higher-power IOT transmitter to pay for a lower-power solid-state transmitter will become a serious consideration. Who would buy used IOT transmitters? Canadian and Mexican broadcasters; after all, those countries are going through their own digital transition, and they'll need transmitters at as low a price as possible in a down economy.


(Speaking of the Canadian and Mexican transition, there will be a glut of unused, yet usable, VHF and UHF transmitters at the end of the US digital transition. These could also be sold to Mexican and Canadian stations in anticipation of their transition.)

 

[11001011]

I think you are missing the point. It's not the inner city dwellers that are going to be effected the most by the DTV transition. It's going to be the people living out in Styx that are already in a fringe area and do not have Satellite.


With Analog you can still watch a marginal signal through the snow. With digital, you have the digital cliff effect. Once you lose enough bits, it's all over, a black screen is all you get.

 

[Digital Rules]

I'm sure most stations will be thankful they will only have to maintain and power up 1 transmitter instead of 2. That should save them quite a bit of money on their electricity bills!!

 

[Jim Shaffer]

It would be nice if cable and satellite would carry all the local stations, but they don't. Even if they're required to in the future, Dish's spotbeam that they chose for my DMA doesn't even cover where I live -- which happens to be a place where I hardly have an analog signal, never mind a reduced-power digital one!

 

[afiggatt]



Quote:
Originally Posted by mikemikeb /forum/post/15488697


Why? The economy is too strained now. The penetration rate of over-the-air is maybe 15-20%, the rest using cable or satellite. People with cable or sat won't care about lower power levels, but the station operators would care about lower power costs. Of those with OTA, most of them are closer to the transmitter; for them, lower power levels mean reduced or eliminated wind-related multipath intereference. Super-long-range OTA viewers are usually not lucrative enough for advertising, anyway, to spend the extra dough on transmitting costs. So it's a win-win-win for broadcasters.

The station owners are ones making the decision to file for 1000 kW digital ERP for UHF channels. They obviously think it is worthwhile to broadcast at the highest power to reach more possible viewers. Besides, if you own a full power low VHF analog station and are staying on UHF for digital, you need the 800 to 1000 kW to get your coverage area closer to what you had with low VHF.


You do realize that a DT UHF station with a 1000 kW ERP is not actually using 1000 kW to power the transmitter? And how do you feel about analog UHF stations running at 5000 kW ERP? (But those will be gone in 40 days. Maybe).

 

[Tower Guy]



Quote:
Originally Posted by mikemikeb /forum/post/15488697


Lower power levels mean reduced or eliminated wind-related multipath intereference.


(Speaking of the Canadian and Mexican transition, there will be a glut of unused, yet usable, VHF and UHF transmitters at the end of the US digital transition. These could also be sold to Mexican and Canadian stations in anticipation of their transition.)

Three incorrect premises:


# 1. The level of multipath is constant. Lower power doesn't reduce the reflections any more than the direct signal.


# 2. In order to maintain profit margins, stations need all the viewers that they can get. If a station were to loose 5% of the audience by reducing power and the profit margin is 5%, the station would no longer be profitable.


# 3. Canada already uses low power solid state UHF transmitters whenever possible. There is no market for used tube type transmitters.

 

[iowegian3]

Is it possible that WRC is using a higher gain antenna than WFDC? UHF transmit antennas with high gain factors may overshoot areas close to the transmitter. I seem to remember hearing stories about how our local UHF used to be received better at 35 miles out than at 15. A second U signed on w/ 5 megawatts ERP and 1970 ft, and it was more stable than the first, which was about 3 meg and 1500'. (both towers were w/in 2 mi of each other)


Anyway, just a theory. Posted data on the two, w/ antenna info in case anyone wants to dig further.



WRC-TV:

Polarization: Horizontal (H) Effective Radiated Power (ERP): 813. kW ERP Antenna Height Above Average Terrain: 242. meters HAAT -- Calculate HAAT Antenna Height Above Mean Sea Level: 312. meters AMSL Antenna Height Above Ground Level: 194. meters AGL TV Zone: 1 Frequency Offset: 0 (zero) Non-Directional Antenna ID No.: 28664 Pattern Rotation: 0.00
Antenna Make: DIE Antenna Model: TFU-26GTH-R 04


WFDC-TV

Polarization: Horizontal (H) Effective Radiated Power (ERP): 325. kW ERP Antenna Height Above Average Terrain: 173. meters HAAT -- Calculate HAAT Antenna Height Above Mean Sea Level: 243. meters AMSL Antenna Height Above Ground Level: 125. meters AGL TV Zone: 1 Frequency Offset: 0 (zero) Non-Directional Antenna ID No.: 76566 Pattern Rotation: 0.00
Antenna Make: AND Antenna Model: ATW28H5-HTOL-14H

 

[Trip in VA]



Quote:
Originally Posted by Tower Guy /forum/post/15494978


Three incorrect premises:


# 1. The level of multipath is constant. Lower power doesn't reduce the reflections any more than the direct signal.

While it doesn't reduce reflections, I've seen lower power make the difference between decoding and not decoding. Attenuators work on multipath. While it doesn't reduce reflections, it reduces the intensity of the reflections (along with the main signal) which sometimes seems like it can make the difference between decoding or not. Don't ask me why it works, it just does in real world situations.

Quote:
# 3. Canada already uses low power solid state UHF transmitters whenever possible. There is no market for used tube type transmitters.

What about Mexico? Their transition isn't until 2022, so they might be interested if they're still using high-powered stuff.


- Trip

 

[afiggatt]

WRC-DT NBC 4 is broadcasting on UHF 48 at 813 kW. WFDC-DT Univision 14 is broadcasting on UHF 15 at 325 kW. The difference in UHF channel frequency and the propagation pattern could be the reason MikeMikeb has problems getting WRC-DT. There are also 2 low power analog stations in DC on either side of UHF 48: WMDO-CA 47 and WWTD-LP 49 (150 kW). They should not be interfering with WRC-DT, but if one is closer in to the broadcast towers in DC, there could be interference in some spots.


WFDC-DT 14 has been granted it's post-transition maximization filing for 1000 kW, so it may be cranking up to 1000 kW as soon as February 18 (depending on whether the station is ready and the whims/last minute panic response of Congress). I guess MikeMikeb will find out then how he likes 1000 kW digital UHF stations (of which there are already 2 in DC: WUSA-DT CBS 9 (34), WTTG-DT Fox 5 (36)).

 

[Falcon_77]

1000kW is a lot of power, but unless stations are willing to build additional translators and/or DTS, then lower power (e.g. 200kW or less) probably won't work well for them, especially for stations moving from Low-VHF.


The US runs far more power than most other countries, due to the single tower approach. e.g., The most powerful DTV transmitters in the UK operate at 20kW now, and will eventually increase to 200kW. The average ERP is just under 4kW, not including the few DTV relays that have signed on. The most powerful DTV transmitters in Germany appear to be at only 50kW. Both run DVB-T, which needs more power to cover the same area.


However, 50kW stations in the US would make a lot of people unhappy. Especially those that have their antennas pointed the wrong way or rely on indoor rabbit ears. While the FCC planning specs are to have outdoor antennas at 30', stations have essentially catered to the indoor rabbit ear model for decades.

 

[Piggie]



Quote:
Originally Posted by Falcon_77 /forum/post/15495705


1000kW is a lot of power, but unless stations are willing to build additional translators and/or DTS, then lower power (e.g. 200kW or less) probably won't work well for them, especially for stations moving from Low-VHF...


While the FCC planning specs are to have outdoor antennas at 30', stations have essentially catered to the indoor rabbit ear model for decades.

I am rural. Actually caught between 2 NBCs.


Interesting though about the designed for reception at 30 feet. That to me is pretty high up for a pole. Well it's right on the edge of guy wires, if not needing guy wires.


Seems a system designed for the 15 to 20 feet range would make more sense. At that height installation if much easier for the average do it yourself person that is not into understanding electronics, TV, etc.


Then again, the FCC is the FCC.... )

 

[MeowMeow]

Dude? Your theory simply isn't born out by the facts on the ground.


Why?


#1 and it's a biggie: if a station reduced power significantly it ceases to be a must-carry in any cities at the fringe. Carriage is the entire TV business model.


#2: many stations are already comfortable operating a 5000kw and 1000kw transmitter with their analog and DTV UHF signals.


#3: the relative cost of running an existing transmitter isn't all that bad. The build out of the tower and initial installation are the monster. That's why you see so many cases where competing companies build on the same tower.


#4: overall operating costs are driven more by the studios required to run a respectable stations. That's why you see the first big, deep cut by poor stations is always local news.


I'm sorry, your genius plan sort of sucks. To be honest, unless you think it is a patentable business model, I'm not even certain why you aired the notion.

 

[arxaw]



Quote:
Originally Posted by mikemikeb /forum/post/15488697


Why? The economy is too strained now. The penetration rate of over-the-air is maybe 15-20%, the rest using cable or satellite. People with cable or sat won't care about lower power levels...

I don't live in DC. I live in the real world and rely on OTA for in-state TV, as do all my neighbors. I like 1,000kW DTV stations.


Some of our area stations are shutting off 5,000kW analog transmitters on 2/17. They are very happy that 1,000kW will cover their huge DMAs.

 

[Piggie]



Quote:
Originally Posted by arxaw /forum/post/15531694


I don't live in DC. I live in the real world and rely on OTA for in-state TV, as do all my neighbors. I like 1,000kW DTV stations.


Some of our area stations are shutting off 5,000kW analog transmitters on 2/17. They are very happy that 1,000kW will cover their huge DMAs.

I don't live in town either. I like more power! The VHFs are the worst. Most of them are running way too low power but that is off topic in this thread.


Another thought. If translator stations are such a great idea, why did they give away channels 52 to 69, which have bad range anyway, mainly due to loss in the feedline and antenna not designed for the upper end of the band. Not to mention if you compare channels in the 20s to those in the 60s, the propagation range changes over that freq spread.


Those would have made great short range repeaters for towns distance from the main tower in the same DMA.


But! and a big butt. It would not solve the sparse and far spread of rural viewers. That takes power. The US is more rural than Great Britain and Germany. To compare their power levels affecting rural viewers is comparing apples to oranges.

 

[jtbell]



Quote:
Originally Posted by Piggie /forum/post/15531517


Interesting though about the designed for reception at 30 feet. That to me is pretty high up for a pole.

When that spec was established (1950s or 1960s) they were probably thinking of antennas attached to the typical houses of that day: two-story, or one-story with a fairly tall attic, then adding a few feet above the roof line. Not modular homes with low or flat roofs.

 

[MeowMeow]



Quote:
Originally Posted by jtbell /forum/post/15532073


When that spec was established (1950s or 1960s) they were probably thinking of antennas attached to the typical houses of that day: two-story, or one-story with a fairly tall attic, then adding a few feet above the roof line. Not modular homes with low or flat roofs.

For that matter, they weren't planning for TV antennas to become a universal symbol of poverty and/or weirdness. If you live in town, there is a bit of a stigma that goes with have a big outdoor aerial attached to your roof. It's indicates to your neighbors that you either too poor to afford cable or that you are a quack.


And that's fine for people like me, because my neighbors are all very aware I'm crazy. But, more image conscious, non-geeks may be less inclined to plant a 30' pole to their house announcing they're a little strange.


Of course, those awesomely hideous clusters of satellite dishes on everyone's homes are reducing some of the stigma.

 

[Tower Guy]



Quote:
Originally Posted by Trip in VA /forum/post/15495240


While it doesn't reduce reflections, I've seen lower power make the difference between decoding and not decoding. Attenuators work on multipath. While it doesn't reduce reflections, it reduces the intensity of the reflections (along with the main signal) which sometimes seems like it can make the difference between decoding or not. Don't ask me why it works, it just does in real world situations.

- Trip

You have described exactly the symptoms of tuner overload.

 

[HDTVChallenged]



Quote:
Originally Posted by 11001011 /forum/post/15491503


With Analog you can still watch a marginal signal through the snow. With digital, you have the digital cliff effect. Once you lose enough bits, it's all over, a black screen is all you get.

You know, I realize that I'm a single data point and that there maybe a couple of "lucky breaks" my way. But, I am 76 miles from the towers in the next DMA over. I have no problem receiving the full power UHF's DT's well over 50% of the time (waiver denial criteria.) In fact, I rely on that market for most CBS-HD programming. OTOH, the analogs, while occasionally viewable through the snow, are not something I would willingly watch except under extreme emergency conditions.


In short, all this talk about "digital cliffs" is a bunch of hooowy ... digital is "usable" for at least 10-15 miles further than analog.


PS: That aforementioned, CBS station is actually only 600kW

 

[11001011]



Quote:
Originally Posted by HDTVChallenged /forum/post/15534258


In short, all this talk about "digital cliffs" is a bunch of hooowy ... digital is "usable" for at least 10-15 miles further than analog.

Not in my case. I live 120 miles from the major network transmitters. Right now I can receive the analog of channels 7 fair and 13 pretty good. Channels 7 and 13 are also currently transmitting their digital signal at full power but yet I can not receive either of them on the same deep fringe antenna

 

[johnpost]



Quote:
Originally Posted by HDTVChallenged /forum/post/15534258


In short, all this talk about "digital cliffs" is a bunch of hooowy ... digital is "usable" for at least 10-15 miles further than analog.

there is a threshold of signal for decoding. if the signal reaching you is over that threshold, which will vary with conditions (weather, ionosphere ) for fringe and greater, then you will get a picture.


with analog it is possible to see something well out of that market in lower quality. the good quality range is greater with digital because either you have it or not. for all the time reception of digital I think the markets are not 10 miles greater than analog, so far there seems to be an overall loss (some markets will gain and others loose), but it will have to wait until the final channels of the transition to see.