My Issue with Digital TV

[vacuum tube]

I am really baffled as to why you can't get WMAR DTV. When WJZ DTV switched to rf channel 13 last Friday, WMAR just switched their video and audio into the same transmitter/antenna system that WJZ DTV was using prior to the switch. So if you were getting WJZ DTV on 38 before the switch last Friday there is no explaination as to why you can't get it now. There has to be something you and I are missing. You might check and see if you can manually delete WJZ and WMAR if they are still in the memory and then rescan. Your antenna seems to be working fine from what you have described. I hope you get it figured out, I'm sure I would be pulling my hair out over this one. WMAR should have one of the best DTV signals out of Baltimore.

 

[HGN2001]

Try the double-rescan method:

Unplug all antennas from your digital tuner and run a full rescan. This should find "0" stations and totally reset your tuner.

Now plug in your antenna, pointed toward Baltimore, and run a full rescan again. This time you should get all of your stations.

 

[vchimpanzee]

What about DTV spacing? I've noticed that there are digital channels in the LA area right next to each other like 32 and 33 (on their RF channels). I would think that would cause interference to each others channels but I guess digital works differently in that respect.

Where I live analog channel 46 was digital channel 47 and analog channel 20 was digital channel 19. Supposedly, the stations used the same tower for both signals.

 

[vchimpanzee]

The short-term solution may be for stations to move back to their pre-transition UHF channels until filters are available to the affected viewers (Or,... "fat chance" wise...., turn all the FM stations down to 10% piower).

I lost a channel that moved back to 8, but they've gotten permission to move back to 35, according to what I've read on this site. I don't know why they can't do that permanently. But it appears lots of people were having trouble.

 

[kenrayc]

Here an interesting situation with my converter boxes. I have a Digitalstream and a Zenith converter box in 2 rooms the 3rd has a HDTV. My CBS affiliate KPGE 47.1 appears on my Digitalstream box on 34.3 instead of 47.1 ,34 is the RF channel, if you punch in 47.1 is says no signal. On my Zenith box its on 47.1 and if you punch in 34.3 it redirects to 47.1. Its 47.1 on my HDTV as well. Even after rescanning it it does the same thing and 47.1 did not change DTV channels on 6/12.

 

[markwooldridge]

I lost a channel that moved back to 8, but they've gotten permission to move back to 35, according to what I've read on this site. I don't know why they can't do that permanently. But it appears lots of people were having trouble.

My guess is that it'll be trickier to get through the red tape of the FCC to get 35 for WHGP than to work through the problems with 8 and get that working correctly. Also it is my understanding that 35 interferes with other stations now and that WGHP had to get a waiver from the other stations involved before 35 could go back on air.

 

[dhett]

Did a check of Phoenix's VHF DTV stations. I live about 5 miles from the towers, which are 1200' above average terrain, so I went down to Coolidge, about 50 miles from the towers. I could get all of the full-power UHF DTV stations and even picked up a 15 kW LPDTV station, KPHE-LD, but could not get the full-power VHFs: KAET 8, KSAZ 10 and KPNX 12. I'm using an antenna with telescoping dipoles for VHF and a UHF loop, so there's nothing wrong with the antenna.

Makes me wonder: for analog, hi-VHF stations had a max power level of 316 kW, compared to 100 kW for the lo-VHFs. So why would the FCC assign the same max power level for both hi- and lo-VHFs in digital?

 

[w9wi]

Makes me wonder: for analog, hi-VHF stations had a max power level of 316 kW, compared to 100 kW for the lo-VHFs. So why would the FCC assign the same max power level for both hi- and lo-VHFs in digital?

They didn't - see http://edocket.access.gpo.gov/cfr_2008/octqtr/47cfr73.622.htm (FCC regulation 73.622) which contains the maximum power limits for DTV stations. (you have to scroll past all the pre-transition channel allotments)

45kw for channels 2-6, 160kw for 7-13.

However, those limits apply only to wholly new DTV stations. Stations that had an analog presence were assigned a power that wouldn't interfere with other stations.

Also, the maximums for low-power stations are the same for low-band and high-band, though that applied in the analog world too.

 

[dhett]

Makes me wonder: for analog, hi-VHF stations had a max power level of 316 kW, compared to 100 kW for the lo-VHFs. So why would the FCC assign the same max power level for both hi- and lo-VHFs in digital?

They didn't - see http://edocket.access.gpo.gov/cfr_2008/octqtr/47cfr73.622.htm (FCC regulation 73.622) which contains the maximum power limits for DTV stations. (you have to scroll past all the pre-transition channel allotments)

45kw for channels 2-6, 160kw for 7-13.

However, those limits apply only to wholly new DTV stations. Stations that had an analog presence were assigned a power that wouldn't interfere with other stations.

Also, the maximums for low-power stations are the same for low-band and high-band, though that applied in the analog world too.

I figured you'd be all over that.

I realized just after I'd posted that it was only LPTV that was the same power for hi- and lo-VHF, but the site went down just after I posted, so I couldn't remove it. :

 

[w9wi]

I realized just after I'd posted that it was only LPTV that was the same power for hi- and lo-VHF, but the site went down just after I posted, so I couldn't remove it. :

Gotta love poorly-timed network crashes ;D

 

[landtuna]

Did a check of Phoenix's VHF DTV stations. I live about 5 miles from the towers, which are 1200' above average terrain, so I went down to Coolidge, about 50 miles from the towers. I could get all of the full-power UHF DTV stations and even picked up a 15 kW LPDTV station, KPHE-LD, but could not get the full-power VHFs: KAET 8, KSAZ 10 and KPNX 12. I'm using an antenna with telescoping dipoles for VHF and a UHF loop, so there's nothing wrong with the antenna.

And I'm still having a different sort of problem.

Living just a few miles further away than you from the S. Mountain towers I can receive every OTA signal just fine except 51 and 27. I don't usually watch 51 so haven't spent any time trying to figure out what is wrong with their signal but I do like RTV which is on 7.2 (RF 27) and am getting a very poor signal (10-20% on my Channel Master in late afternoon and only marginally better other times.

The antenna is a whopping large combo VHF/UHF and is direct line of sight distance about 10 miles.

 

[dhett]

27, 38, 45 and 61 have been my problems. 45 can be especially a beast. Mind you, I'm using indoor antennas, so that doesn't help matters. One thing I noticed is that if the antenna isn't pointed perfectly, signal strength really drops off.

I love the picture quality of DTV, but it does have its reception issues, and when it's giving problems, the best picture quality is useless. Someone compared DTV to 1951 all over again. I think they're spot on.

 

[landtuna]

Yesterday afternoon, when RF 27 went into its normal late afternoon failure, I took another tack. I installed a little bow tie near my west-facing window (pointing directly at South Mountain) then fed that into the converter with a combiner which is hooked to my large outdoor antenna. It boosted the signal by 30-40% and is now good enough that pixilation and audio breakup are minimal.

I was kind of expecting new problems with the two feeds since they arrive at the converter at different, but probably not significant, times. But so far no issues.

Now I wonder if I installed the bow tie at the large antenna site, would I get equal or better results? Might give that a try today.

This DTV stuff is making me dizzy!

 

[landtuna]

Tried installing a small, indoor, bow tie antenna in conjunction with the large outdoor antenna but it effectively killed the entire RF 27 signal. Went back to the original setup and am back to between 60-80% (although it constantly fluctuates).

Guess that's a good as it's going to get. Still don't understand why 27 is the only channel with low signal strength.

 

[dhett]

It could have something to do with KUTP RF26. They're the reason KAZT cited for their request to move to RF36.

It puzzles me, though, that KAZT has so much trouble with KUTP when KPHE RF16 doesn't seem to have a problem with either KNXV RF15 or KPHO RF17 and KEJR RF40 doesn't seem to have a problem with KTAZ RF39. I'm guessing the issues on K38IZ-D are just due to poor setup, although they weren't crazy about locating next to KTAZ either - at the time, they didn't think they had a choice.

KAZT's displacement application seems to confirm what you're experiencing:

http://fjallfoss.fcc.gov/cgi-bin/ws...xt=25&appn=101260410&formid=401&fac_num=72618

 

[landtuna]

KAZT's displacement application seems to confirm what you're experiencing:

http://fjallfoss.fcc.gov/cgi-bin/ws...xt=25&appn=101260410&formid=401&fac_num=72618

Interesting. I note that this was filed 11 months ago. What is the normal turnaround time for a request of this type?

 

[dhett]

KAZT's displacement application seems to confirm what you're experiencing:

http://fjallfoss.fcc.gov/cgi-bin/ws...xt=25&appn=101260410&formid=401&fac_num=72618

Interesting. I note that this was filed 11 months ago. What is the normal turnaround time for a request of this type?

It would have been useless for the FCC to act on it until 2 weeks ago, as that is where KPNX had their pre-transition operations until June 12. Cutoff for applications is June 30, and I'm sure the FCC has a backlog, but I'm sure they'll start processing applications for LPTV on or shortly after July 1.

Then there's the whole issue of coordination with the Mexican government, due to proximity to the border. That can take months, even years.

 

[vchimpanzee]

Yesterday afternoon, when RF 27 went into its normal late afternoon failure, I took another tack. I installed a little bow tie near my west-facing window (pointing directly at South Mountain) then fed that into the converter with a combiner which is hooked to my large outdoor antenna. It boosted the signal by 30-40% and is now good enough that pixilation and audio breakup are minimal.

I was kind of expecting new problems with the two feeds since they arrive at the converter at different, but probably not significant, times. But so far no issues.

Now I wonder if I installed the bow tie at the large antenna site, would I get equal or better results? Might give that a try today.

This DTV stuff is making me dizzy!

I think I had a bow tie years ago.

They mentioned this option as something you should pull out of the closet way back when people were first starting to watch digital TV.

 

[landtuna]

It puzzles me, though, that KAZT has so much trouble with KUTP when KPHE RF16 doesn't seem to have a problem with either KNXV RF15 or KPHO RF17 and KEJR RF40 doesn't seem to have a problem with KTAZ RF39.

I did something last night I almost never do - watched KNXV (RF 15) for two solid hours. During that time I had about half-a-dozen pixilation events although the signal strength (as measured by my Channel Master CM-7000) was a solid 100%. Each event lasted only a second or two but I was surprised that any occurred.

Could it be that RF16 is impacting RF15 instead of the other way around?

 

[fybush]

I did something last night I almost never do - watched KNXV (RF 15) for two solid hours. During that time I had about half-a-dozen pixilation events although the signal strength (as measured by my Channel Master CM-7000) was a solid 100%. Each event lasted only a second or two but I was surprised that any occurred.

Could it be that RF16 is impacting RF15 instead of the other way around?

With 100% signal strength and pixilation, I'd begin to suspect that you're overloading the receiver, which is surprisingly easy to do.

Time to break out the infamous "bent paper-clip" antenna and see what it does for you!