OTA DTV Stations using RF channels 2 thru 6---do they like or dislike it?

[cd637299]

Since I posted on the 87.9 thread, I thought I'd open this up....

Of the handful of OTA DTV stations using RF channels 2 thru 6, has there ever been a survey of them (the employees of the stations in question), as to whether they like being on that channel OR would rather find a hi-VHF or UHF channel, if they had their druthers?

I understand that WPVI Philly wants off 6 badly, but there is no other channel in the area of which to move. WTVF Nashville has CP for UHF 25 (from RF 5), and I am sure they are anxious to go there.

One of our members told me that WBRA in Roanoke likes being on RF 3....who woulda thunk it?

I also recall the thread in the San Antonio board about lousy local reception of KCWX (DT 5).

I would think that with the few outdoor antennas now geared for lowband VHF, that *all* these stations would love to move.

Anyway, info *from* these stations/employees I would like to check out. Anybody?

(I would limit this to full-power 2-6, but LD's are okay to mention here too.)

cd

 

[spunker88]

Wasn't there a time when this was the most desired band due to its favorable power vs distance ratio. Unless the FCC has other plans for the band, such expanding the FM band, they should increase power limits for VHF-L DTV to make it more attractive. From what I understand the extremely low power limits make this band less desirable.

 

[boiseengineer]

Of the many problems with Low-VHF DTV is static like lightning destroys it.
Story of an early low band DTV station. The first lightning storm that hit completely obliterated their off air monitor at the studio. They thought the DTV transmitter was off the air.

 

[W2JUV_AL]

I gotta believe that CBS-6 (WRGB) in Albany NY is not entirely satisfied with their return to Channel 6. Prior to the cutoff date (June 2009?) WRGB-DT was on Ch. 38 or 39. Since returning to Ch 6, power has been increased once and the FCC database lists several applications for translators. Now I understand that WRGB 6.1 is simulcast on a subchannel of sister station WCWN. Sounds like WRGB went from having the best analog signal in their market to the worst digital signal.

 

[MarioMania]

Is the FCC still going to claim I think 30 UHF Channels for Broadband and force Stations back on VHF??

 

[w9wi]

The current plan (part the FCC's and part Congress') is to run a "reverse auction" to find out how many TV stations can be bought out from a fixed pool of money. They'll then juggle around the remaining stations to open as much spectrum as possible. The FCC will be able to force stations to move to different channels, but they won't be allowed to force a station to move from UHF to VHF, nor from VHF-high to VHF-low. (kinda suggests they will be allowed to ask stations to voluntarily move & possibly offer them money to do so)

LPTVs won't receive any protection here. My suspicion is we'll see some number of LPTVs forced to move from UHF to VHF, and to VHF-low. The FCC has also been hunting for Class A stations which aren't meeting Class A requirements, and has been telling them they're going to be modified back to LPTVs unless they can show good reason not to.

 

[anotherguyTN]

I've heard thsat WMC in Memphis has a filed a request to move from 5, but I don't know all the details.

 

[dave73]

Since WOCK-CD had a poorly directional signal on 13, they thought they could do well on 4. At only 300 watts, their signal can't be received at all in most of the market, unless you have not only an antenna optimized for 2-6, but a pre-amplifier as well. Had KM LPTV been successful at getting the license for channel 30 (now held by Daystar, who nearly let it expire), they would have moved there, as more people can receive an LPTV station on UHF than on VHF (UHF allowed 15kw while VHF originally only allowed 300 watts, but new LPTV VHF's are allowed 3kw). I don't see why why the station owner doesn't try to put in an application to go to 3kw, & see if that would make a difference. WLFM-LP initially requested to flash cut to digital on channel 6, but withdrew it, claiming interference. I believe for them, they withdrew it, because they would no longer be allowed to use channel 6 as a radio station (won't be able to after 2015). 3kw is more than WBBM-TV was allowed for channel 3, when they were at only 2.8kw (of course now, they're now on channel 12, but I'll get to them in a moment).

WLS-TV didn't originally request another channel when they were forced to go back to channel 7. There have been nothing, but complaints since that time. They however have kept channel 7, while they forced WCHU-LD off of channel 44, & have been trying for over 2 1/2 years to get the channel 44 facilities working on the Sears Tower. Their latest attempt when a new antenna was installed, that those within 10 miles of the Sears Tower couldn't get them on 44, but could get them on 7. They have gone back to broadcasting 44 on the John Hancock, trying to get another antenna that will allow viewers in the entire market get the station on the Sears Tower, & vacate channel 7. Channel 7 was broadcasting from the John Hancock, but it's back on the Sears Tower, transmitting from their original VHF antenna that they used from 1973 to 1982 (the VHF antenna used from 1982 to 2010 was removed). I personally would have preferred to see WLS-TV seek a power increase, but they have WOOD-TV across Lake Michigan, who also chose channel 7 as their final channel, & they're transmitting at much higher wattage. I always got WLS-TV in better on 7 than on 44, or their pre-transitional channel 52.

WBBM-TV is another station that has had problems with their signal, but not to the same extent as WLS-TV. They were initially on channel 3, but most people couldn't get them (I did & had little trouble getting them when there was lightning). They made a deal with WTTW to acquire their antenna on the Sears Tower, as it would have been cheaper than to build new facilities on the John Hancock. Their original plan was to move to channel 11, but they learned that the power for channel 11 wouldwould only be 1.8kw, while they had 2.8kw on channel 3. They changed their final channel to 12 after learning that WISN Milwaukee, would be staying on channel 34. WBBM-TV would have had to protect WLFI Lafayette, IN, WGVU Grand Rapids, MI, & then WMSN Madison WI (they're now on 49), due to too many channel 11's around Chicago. They're at 8kw on channel 12, but not everyone receives the station. They were granted a translator on channel 26, but they had to have it located away from the downtown area in order to prevent interference with translator W25DW-D on channnel 25. I don't know how soon the translator will go on the air, but I know it'll be located on the tower on top of the old WXRT studios at 4949 W Belmont Ave in Chicago (same location for CBS's backup FM stations). It'll mainly be those closest to Chicago that will pickup the translator. Most suburban people will have to make VHF work.

 

[spunker88]

So what was the reasoning for cutting power limits so much? I have a local WWNY that was on 7 in analog and went to 7 in digital. They were ~300kw on channel 7 in analog but are only 25kw in digital.

Interesting thing is I just checked their FCC entry I saw an application for 42kw ERP and attached to the application is a letter to the FCC from all channel 7 TV stations in New York all asking for power increases and all accepting potential interference from one another.

 

[KeithE4]

So what was the reasoning for cutting power limits so much? I have a local WWNY that was on 7 in analog and went to 7 in digital. They were ~300kw on channel 7 in analog but are only 25kw in digital.

Because, at least in theory, digital transmissions can cover the same distance with lower power, and you'll still get a perfect picture with a lower signal level. Reality is different. Not only does one have to deal with lower signal levels, but also with multipath from passing planes, birds, and even clouds. I don't care what they say about error correction and eliminating multipath problems, it ain't working very well.

In some cases (like mine) the position of the sun in relation to the path between tower and receiver causes problems. FM overload on VHF-Hi channels also factors in, especially when you're only 5 miles from the towers like I am. In Phoenix, not only does South Mountain hold all the TV transmitters, but also over a dozen 100 kW FM sticks. They overload almost every radio in my house, and may be the cause of some of my VHF-TV issues. Unfortunately, my local Best Buy and Fry's Electronics don't carry FM traps, so I've been out of luck there. A high-pass filter with a cutoff frequency of 174 MHz would probably work even better.

When I turn my living room ceiling fan on and off, the resultant milliseconds-length spark from the switch causes the VHF-Hi (8, 10, & 12 in my case) to go out for a split second. The switch is 10 feet from the rabbit ears, and the fan is about 5 feet away.

The advantage of digital is, of course, HDTV. But the disadvantages still need to be overcome. Higher VHF transmit power levels will help, but not cure it completely.

 

[K4WRF]

Isn't it ironic that what was once prime and no-mans-land (respectively) real estate TV RF spectrum have now swapped positions! VHF presents a multitude of issues; noise, phase cancellation, wrong receive antennas and high percentage of bandwidth as compared to UHF. If a TV operator is saying they are pleased with low-band and perhaps high-band performance, they're smoking something and we ain't talking the transmission line!

Best regards,

w/

 

[DeadElvis]

I've heard thsat WMC in Memphis has a filed a request to move from 5, but I don't know all the details.

WMC has filed for a replacement channel on 17. That would displace an LD that is Spanish, with some local programming.

I get a reliable signal from WMC, for the most part. Unlike most viewers, I know enough to build a lo-band loop for 5; it works pretty well. But it does have issues with electrical interference.

What's unfortunate is that WMC could have gotten another channel. "The suits," I'm told, were afraid to give up that heritage channel.

DE

 

[w9wi]

The other thing is that analog and digital power comparisons are apples & oranges.

TV stations (both analog & digital) are amplitude-modulated, which means the power is always changing.

- Analog power is measured at peaks, when the station is using the most power it will ever use. (the times of these peaks are predictable)
- Digital power is measured as an average over time.

VERY roughly, digital average power is about 1/2 peak.

To put it differently...

WWNY's 25kw average digital is 50kw measured the way they measured it in analog.

WWNY's 300kw peak digital is 150kw measured the way we measure it in digital.

50kw peak digital vs. 300kw peak analog is still too much of a difference, but it's a lot closer than 25kw vs. 300.

 

[BobOnTheJob]

To answer the question of why everyone's power is lower, the fact that they are now shoe-horning the same number of signals into fewer channels is a factor as well. On paper, they'll interfere with each other at previous power levels. In reality, they are interfering with each other at the new power levels. Great example...in Charleston,IL you can watch WILL DT 9 (42 miles) on rabbit ears in the afternoon when the band is 'normal'. In the morning, the most directional yagi won't receive WILL because WISH DT 9 in Indianapolis at 107 miles causes just enough interference that WILL won't lock. HDTV needs MORE protection to be reliable, but the FCC gave equal or less on paper--and a lot less in reality. That said, I've had a great experience with HD reception (realizing I'm in the minority). At 70 air miles, all of the Louisvville,KY stations are there 24/7 (including WHAS DT 11) and WKRC DT 12 Cincinnati is about 90% reliable at 80 air miles. It took a spectrum analyzer on my TV coax to see some FM overload which I notched out. That step alone made a large difference, but the average viewer doesn't have access to such equipment so they walk away with a very low opinion of OTA HDTV.

 

[frankberry]

Digital power is measured across the entire 6MHz channel since there is essentially no carrier.
In our case, it takes a transmitter rated at 60 kilowatts for NTSC to produce about 20 kilowatts of digital.

 

[spunker88]

Up until last year we had CIII-6 in Ottawa, ON with 50kw ERP and CJOH-6 in Deseronto, ON (west of Kingston, ON) with 100kw. During tropo it was possible to pull in both just by moving the antenna.

Now CJOH-6 is still around in analog at 100kw, but CIII-6 went digital on channel 6 with 3.3kw digital ERP. I wonder if the interference from CJOH-6 via tropo is enough to affect reception of CIII-6 southwest of Ottawa going towards Perth/Smiths Falls. This area is also served by the big CIII-2 Bancroft so at least they have another Global signal to view if they can't get Ottawa at least until they shut off analog in Bancroft.