The lack of digital reception on channel 13 is no surprise at all and nothing to do with VHF versus UHF propagation.

Yes and no I just think the way they predict the propagation is wrong.

In the application of WVNY there's a coverage map which show that they were expecting the coverage to be equal to the analog.


They also mention that the limit for their assignation is (15kw) but they apply for 10 kw. seehttp://svartifoss2.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=142941


Reallity is that there coverage is far from what simulation show.

http://www.tvfool.com show a different picture which for my location and it look quite right.

http://www.mediafire.com/?290d101wbdz (Here's the analog)


http://www.mediafire.com/?6n4pjd9xvmm (Here's the WVNY-DT coverage map)

Sorry don't use the link of my previous post...

Quote:
The lack of digital reception on channel 13 is no surprise at all and nothing to do with VHF versus UHF propagation.

Yes and no I just think the way they predict the propagation is wrong.

In the application of WVNY there's a coverage map which show that they were expecting the coverage to be equal to the analog.


They also mention that the limit for their assignation is (15kw) but they apply for 10 kw. seehttp://svartifoss2.fcc.gov/prod/cdbs...ibit_id=142941


Reallity is that there coverage is far from what simulation show.

http://www.tvfool.com show a different picture which for my location and it look quite right.


This is the DT coverage.
http://i200.photobucket.com/albums/aa19/jajoflo/WVNY-DT.jpg

This is the analog
http://i200.photobucket.com/albums/aa19/jajoflo/WVNY-ANALOG.jpg

When your at the FCC site look at the relative field plot for WVNY-dt and not the contour pattern for a more accurate look at what direction their signal is going.With 1.5KW north there will not be any reliable reception beyond that contour of reception north.Here in Toronto the Buffalo fox was at 35kw Omni then they went 1000kw directional and the signal toward Toronto is much weaker now.

Montreal is located North-West from the transmitter, not North. The antenna pattern has a beam going West-Northwest.

Everyone at the station says that they are certain that their signal is adequate to reach Montreal. They have their head in the sand overestimating VHF.

Foxfan look at the relative field plot on the FCC site not the contuor which is wrong or over estimated.There is no signal to the northwest.This is no doubt a result of the crtc not giving approval for omni directional transmitter,yes Canada.Why dont they return to 22 and use that antenna at shut down,oh yes the CRTC strikes again.The station engineer knows they are not sending anything northwest.

WCAX-DT (using 53 right now) will use 22 after the analog shutdown.

Yeah, because stupid WVNY prematurely gave up channel 22 even before they had put 13 on the air to see how far its signal would really go. The station engineers really did tell me that the expected to reach Montreal. The only option now would be to move to channel 33 or 44 in 2009.

Foxfan look at the relative field plot on the FCC site not the contuor which is wrong or over estimated.There is no signal to the northwest.This is no doubt a result of the crtc not giving approval for omni directional transmitter,yes Canada.Why dont they return to 22 and use that antenna at shut down,oh yes the CRTC strikes again.The station engineer knows they are not sending anything northwest.Industry Canada, not the CRTC, manages the RF spectrum. IC coordinates with the FCC on TV transmitters within 150 miles of the border. FCC doesn't want Canadian signals radiated into the US and Canada doesn't want American signals into Canada. Directional antennas provide the means to taylor the station coverage to meet coordination requirements. In the case of VHF 13, the antenna pattern provides protection to CJOH and other channel 13 assignments in Canada.
I checked the channel 13 antenna pattern in the FCC database for WFFF. At 270 degrees (west) the signal is almost at full power (99.8%) but at 310 its down to 71% and at 320 its at 56.5% (5.65 kw). foxfan is correct about a beam going roughly west-northwest but its still not a lot of power compared to WFFF's 1 Megawatt omni pattern on analog channel 22.

I think you meant WVNY, not WFFF.

But anyhow, on the issue of The station is directional with maximum power toward 130 degrees and very little to the north, around 1.5 Kw. The lack of digital reception on channel 13 is no surprise at all and nothing to do with VHF versus UHF propagation. That doesn't explain why WCAX analog, which is broadcasting on channel 3 at 38kw OMNIDIRECTIONAL was never really watchable either (even with channel 2 off the air). The over-estimation of VHF propagation over UHF really IS a major factor.

GeorgeMx Industry Canada ,CRTC its all the same.Industry is just a puppet for CRTC.Vhf is subject to more static interference and more multipath signals with less directional antennas making vhf digital less desirable compounded by low power levels

Industry is just a puppet for CRTCActually rob50312 if you read through GeorgeMX's previous posts here at DHC you'll see that he's very keenly knowledgeable about the CRTC, Industry Canada, and such things so its best to hear him out... ;)

You are right foxfan, I meant WVNY not WFFF. With respect to WCAX, 38 kw is not much power for clean analog reception. Low band VHF suffers from manmade interference from noise and impulse sources such as motors and dirty insulators on high voltage power lines (corona discharge).

GeorgeMx ... Vhf is subject to more static interference and more multipath signals with less directional antennas making vhf digital less desirable compounded by low power levelsLow VHF and high VHF have different characteristics. Low VHF is less desirable, but high VHF is more desirable than UHF.

VHF channels go farther than UHF channels because free space loss on lower frequencies is lower than on high frequencies. Channel 7 is 174 to 180 MHz, channel 69 is 800 to 806 MHz, that's a big difference in frequency. UHF analog transmitters can be licensed in the US up to 5 megawatts to equalize coverage with VHF. An example of 5 megawatt analog UHF is WNYB, channel 26, the religious broadcaster from Jamestown, NY.
Signal losses are also much lower on transmission lines at lower frequencies. This is a significant factor when a broadcaster wants to get significant amounts of power up a 500 to 1000 foot tower. Lower losses at higher frequencies requires large waveguide (think 4, 6 or 8 inch pipe) to carry kilowatts of RF power. The stuff is heavy and has to be supported on a tall tower, adding very significant weight and cost to the installation.
Power conversion efficiency is better at VHF than UHF. More of the electrical power used by the transmitter ends up as RF energy, less is wasted as heat.


Transmitters are a major expense to broadcasters both for capital and operating cost. They run them for 15 years or more to capture full value from their investments. Electrical costs for UHF transmitters are a real industry issue particularly for the very high power installations. For smaller market stations that are barely hanging on financially, and public television stations, transmitter operating cost is a big deal.

The requirement for the FCC process to assign digital channels and power levels is replication of analog coverage. As an example of what happens when going from VHF to UHF, consider WROC Rochester on VHF channel 8 for analog. The ERP is 316 kilowatts. The DTV assignment is channel 45 with an ERP of 1 megawatt. The UHF transmitter will require significantly more power to operate unless it is replacing a very old VHF analog transmitter.

The directional antenna helps reduce the RF power requirement into the antenna because the directional pattern focuses the energy toward the desired coverage area. Omni antennas can waste a lot of power providing signals in areas that the broadcaster has no need to cover.

Directional antennas were not commonly used when most of the VHF stations went on air in the 40s, 50s and 60s. The frequency bands were less crowded and getting TV service to everyone was an important public policy consideration. The move to digital is intended to allow reclaimation of valuable UHF spectrum for mobile purposes. Packing stations into fewer channels requires more attention to limiting coverage to the intended reception areas to minimize interference. Industry Canada and the FCC cooperate to achieve this objective. They both want spectrum back for mobile and don't want to waste capacity in the TV bands due to perpetuation of sloppy omni coverage patterns.

Directional antennas are available for VHF reception but they tend to be much larger due to the longer wavelengths. Stacking VHF antennas increases gain and creates a more directional antenna pattern, just as it does with UHF.

VHF low band (54 to 88 megahertz, channels 2 to 6), appears to have problems for DTV stations due to impulse noise and interference bursts from lightning. I expect that these channels will eventually be vacated in favour of VHF high band and UHF. VHF high band (174 to 216 megahertz) does not seem to have these noise and impulse problems while it benefits from the better economics of VHF transmission. The physical size of the antennas is much smaller than VHF low band.

The origin of this particular discussion was reception problems in Montreal from WVNY on channel 13. I think it is fair to say that 10 kw directional is not adequate for decent reception in Montreal with typical home antenna systems. The signal level is low and there is potential for interference from CJOH. The broadcaster could increase power to 15 kw but the change in signal level will only be about 1.5 dB. WVNY will have to change channels to significantly increase power because of the requirement not to interfere with channel 13 in Canada or possibly other locations in the US. My guess is they have enough signal across the border to facilitate reception by Videotron in Montreal or in a closer location to Burlington on the Videotron fibre network, assuming that Videotron carries their digital signal.

Burlington, Vt. is TV market 90 in the US, right between Cedar Rapids-Waterloo-Iowa City & Dubuque, IA and Harlingen-Weslaco-Brownsville-Mcallen, TX. In other words, it is small market with 5 competing commercial stations. Saving money has to be a priority when compared with providing off-air reception to the bilingual city of Montreal, unless they are selling a huge number of commercials to Quebec advertisers. If they aren't getting a lot of revenue out of Montreal, why bother serving it?

Most of the local ads on WVNY (outside of simsubbed hours) ARE from Montreal. The station is in a joint sales agreement with WFFF, and both stations put "Montreal" in all their local IDs. Viewership in Montreal definitely IS important to them. Burlington is market 90, but if you count the Montreal viewers, it becomes a top 15 market.

As for causes of interference, CJOH isn't really a problem. CKTM Trois-Rivières is, since the directional pattern of WVNY is purposely made to protect CKTM. Their UHF stations 16 and 45 are receivable in Montreal.

One thing that puzzles me is that two or three nights ago, there was some major tropo in the Champlain Valley. The LP station 39 from Barre was coming in clear, as was 28 from Rutland, and I could see 41 from New Hampshire. However, WVNY did not improve AT ALL! Was this because the tropo didn't extend down to the VHF frequencies or because it also enhanced CKTM's undesireable signal cancel out the improvement that would have normally made WVNY better?

Nevertheless, I still stand by my position that VHF goes farther than UHF is a myth. Every time I've travelled somewhere with my portable TV, I've always received the UHF stations of an area I'm approaching before the VHF stations. Obviously, the size of rod antennas is a factor, if it's so much better we shouldn't have to continuously look for excuses to explain why it's really not better in practice.

One thing that puzzles me is that two or three nights ago, there was some major tropo in the Champlain Valley. The LP station 39 from Barre was coming in clear, as was 28 from Rutland, and I could see 41 from New Hampshire. However, WVNY did not improve AT ALL! Was this because the tropo didn't extend down to the VHF frequencies or because it also enhanced CKTM's undesireable signal cancel out the improvement that would have normally made WVNY better?My guess is CKTM was canceling the improvement, because for me WVNY was at 95% to 97%.

Anyone have some DT reading on UHF 26? I will check what this could be.

WTEN from Albany?

WTEN. That must be it, I will check this more often just in case it lock so I would be sure of what it is.

Most of the local ads on WVNY (outside of simsubbed hours) ARE from Montreal. The station is in a joint sales agreement with WFFF, and both stations put "Montreal" in all their local IDs. Viewership in Montreal definitely IS important to them. Burlington is market 90, but if you count the Montreal viewers, it becomes a top 15 market.OK, I accept that WVNY is serving the Montreal market. You state that the station puts the Montreal ads in programs that do not get substituted - effectively making the point that station management is really interested in the Montreal cable audience. Cable viewing makes the business viable, not the off-air viewers. As long as they have enough signal into Quebec to provide reliable reception for cable they have done what they need to do from a business perspective.


As for causes of interference, CJOH isn't really a problem. CKTM Trois-Rivières is, since the directional pattern of WVNY is purposely made to protect CKTM. Their UHF stations 16 and 45 are receivable in MontrealI don't doubt your comment that the directional pattern provides additional protection for CKTM. The overall low power of the station provides protection in other directions for co-channel stations. If they were operating with high power, say with 100 kw or more, the directional antenna pattern might have been designed to reduce power toward the Ottawa area as well.

One thing that puzzles me is that two or three nights ago, there was some major tropo in the Champlain Valley. The LP station 39 from Barre was coming in clear, as was 28 from Rutland, and I could see 41 from New Hampshire. However, WVNY did not improve AT ALL! Was this because the tropo didn't extend down to the VHF frequencies or because it also enhanced CKTM's undesireable signal cancel out the improvement that would have normally made WVNY better?"Tropo" is one of several atmospheric phenomena that cause unusual TV reception. Thunderstorms and ducting (temperature layers) can cause it as well. Unusual atmospheric conditions can favour some frequencies and block others. Geometry also plays a part with some locations getting the unusual conditions while others do not. The stations you mentioned are south southeast of Montreal and in the range from 28 to 41. WVNY is in the right direction but roughly 340 MHz lower than the lowest channel you report.

Nevertheless, I still stand by my position that VHF goes farther than UHF is a myth. Every time I've travelled somewhere with my portable TV, I've always received the UHF stations of an area I'm approaching before the VHF stations. Obviously, the size of rod antennas is a factor, if it's so much better we shouldn't have to continuously look for excuses to explain why it's really not better in practice.VHF and UHF stations go as far as the RF engineer designs them to go. In general, coverage is less expensive in capital and operating cost on a VHF channel than a UHF channel. Stated differently, if the objective is a specific signal level 40 miles from the transmitter site, you can do it on UHF or VHF. The difference is the effective radiated power on the VHF channel will be a lot lower and as a result cost less to build and operate.

TV engineers design TV station coverage to place an 'A' contour in the principal market (local reception) and a 'B' contour (need an outside antenna) in other selected areas. Using more power than necessary results in extra, unwarranted cost and risks interference to other stations on the same channel. The resulting signal is not optimal for distant reception with the rod (monopole) antenna on a portable TV. The rod antenna has little gain or directionality, and since you are travelling I assume you are in a car, truck, motorhome, train car or some other metal structure that will shield the antenna and block the RF signals in different ways depending on frequency and direction. The height of the TV station antenna, elevation of the road, and the surrounding terrain, buildings and trees will also be factors in determining which channels are received first.

Free space attenuation (loss) is lower for VHF than UHF frequencies - that's basic physics. If you radiate the same amount of power on a VHF channel and a UHF channel, the VHF channel will go further. You can find the formulas in an RF Engineering handbook. Loss in coaxial cable is also lower, for example, in Belden RG59 drop cable, loss per hundred feet is 1.8 dB at 60 MHz (channel 2), 3.7 dB at 216 MHz (channel 13), 5.8 dB at 450 MHz (channel 14 is 470 MHz) and 6.3 MHz at 550 MHz (channel 27). For those who are not familiar with dB values, a loss of 3 dB is equal to half the power of the signal. The dB scale is logarithmic, not linear.

You have developed an opinion about VHF versus UHF from experiences with a unique set of consumer equipment. Based on your descriptions of the equipment and how it is used, what you are really observing is the performance of the equipment in your mobile viewing application. An external antenna mounted outside the vehicle might change your conclusion.

Well, for now yes, but launching all four network stations in digital this past year should have been seen as a golden opportunity for those stations to use the over-the-air digital option to circumvent the simsubs and reach the Montreal viewers directly even in primetime. It was never the case with analog because the picture would be better on CFCF or CKMI, but now with digital, they could have done a lot more to promote the OTA alternative and KILL off these useless middlemen! It would be so nice to see the U.S. networks buy up all the border stations to serve this purpose. :D

The US networks have no interest in Canada. They don't own the majority of the programs they air, except for news, and they don't buy the Canadian rights to air the sports and entertainment programs. The program producers, sports leagues and teams (the owners) sell the Canadian broadcast rights to Canadian networks.

US television is so expensive to produce that prime time drama just breaks even based on revenue from first run (network) US broadcast rights. The owners of the shows make their profit from foreign sales and syndication. The owners would be very happy if the US broadcasts never appeared on Canadian TV screens as they would not have to make allowances for Canadian stations' loss of audience to US stations.

Use of the term "middlemen" to describe Canadian broadcasters is loaded with irony. The Canadian broadcasters have licenses to serve Canada and buy the Canadian rights to the programs. The US network affiliates, US broadcasters owned by someone other than the networks, are the true middlemen for both Canadian and US viewers.

Well, that's why I also wanted the FCC to SCRAP the stupid 35% national ownership cap so they can all become network-owned-and-operated.

As for not owning the majority of programs they air, that has been changing, with all the networks being owned by companies who own studios. Except for a few exceptions (like House which Universal sells to Fox and Boston Legal which Fox sells to ABC), most of the networks' schedules are shows made by their own companies.

Anyhow, back to topic, WVNY really has to do something, because all three others stations will suffer as a result of this. If one could get all 5 networks, they'll consider the OTA alternative, but if they are missing one of the "big 4" like ABC, they'll stay on cable or worst Bell and be simsubbed to death.