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San Francisco, CA - OTA - Page 129

post #3841 of 10425
Quote:
Originally Posted by DEEPFRINGEGUY View Post

VideoJanitor,

Are you perhaps on cable or satellite? OTA is uncompressed, full-HD. And KVIE has done an excellent job on 6.1 (real UHF 53; soon to be ch. 9) relative to all the other HD subchannel stations that I pull in OTA. KVIE has a higher HD content on their HD subchannel, based on my viewing experience. It is very close to upconverted DVD or Blue-Ray. Not the sound mind you, the picture... I still haven't tried to see what the sound would be like if I ran it through the Marantz SR75000.

A lot of times, I've noticed that KVIE will tend to show more music-type shows on their SD subchannel 6.2, also. So maybe that was the SD subchannel you were watching?

OTA can be up to 5 times better quality than cable or satellite, that's why asked the question above...

DeepFringe,

No sir (assuming you are a "sir" -- apologies if you aren't!), I am watching OTA. That image was from KVIE's main channel, 6-1. I'm not saying it looks like that ALL the time, but whenever there is more than a little bit of motion, it starts blocking.

I also recorded that program using an ATSC capture device, and as I said before, the program was only allowed about 11 MB/s. So although you are correct that OTA broadcasts are theoretically capable of around 20 Mb/s (19.39 Mb/s), that's the payload for the entire stream -- what you actually get for each individual stream is an entirely different matter. In this case, there is only ~11 Mb/s allocated to the main channel. That's just barely above the top bit rate for SD DVD, and only about 1/3 of the average Blu-ray disc.

That said, if it looks good to you, that's all that matters! I'm just sayin' ...
post #3842 of 10425
Quote:
Originally Posted by DEEPFRINGEGUY View Post

I think it's a big can of worms because there are a lot of variables. Some programs are not very high quality to begin with and when they're broadcast on HD channels they're only as good as the original source. Maybe one of our broadcast engineers will chime in....Can you see a difference?

I'm a broadcast engineer, and yes I can see a difference. There is a definite difference in the quality of programs that are delivered for air, but I have never seen anything come in that was blocking -- virtually everything we receive is satellite delivered at around 40 Mb/s. Can't really find any flaws with it there. Once is goes through the encoder for air, it gets shaved down to around 16 Mb/s, and then, it's not nearly as good.
post #3843 of 10425
Well, being a broadcast engineer, I'm sure you know quite a bit more about the technical aspects and the bits & bytes than I do. I didn't see that particular feed that you snapped a picture of, but some of KVIE's feeds are of lesser quality; so maybe that feed was one of them...

I also don't see a noticeable difference between BlueRay and upconverted DVD on my Kuro. When I'm down at Magnolia, watching a movie, I always have to ask the guy's there if it's DVD or BlueRay...They usually don't know and have to pop the disc and look!
I actually stopped buying BlueRay because of this. KQCA has movies on the weekends, and some of them come in really close to BD/DVD for me...


Best Regards,
- DFGY (GY=Guy...)
post #3844 of 10425
Quote:
Originally Posted by DEEPFRINGEGUY View Post

I also don't see a noticeable difference between BlueRay and upconverted DVD on my Kuro. [...] I actually stopped buying BlueRay because of this.

A Kuro? I'm jealous -- those are great TVs. But you don't see much difference between a Blu-ray disc and an upconverted DVD? Well, I guess we'll have to agree to disagree on that one -- to my eyes, there's no comparison. Just the opposite of you, I stopped buying regular DVDs -- if it's not Blu-ray, I don't want it!
post #3845 of 10425
Quote:
Originally Posted by scottndsky View Post

I have a question on that topic...

I have heard that the 8VSB OTA broadcasts quite often provide more Mbps than the corresponding QAM transmissions from Comcast. I have both OTA and Comcast cable in San Jose. Take, for example, KTVU-HD. In theory, would I expect a better picture and/or sound from Comcast (ch. 702), or directly from the KTVU transmission from Sutro (2-1)?

At the moment I have a CM4228 going directly to the TV. The Comcast signal is being received by my Tivo HD. The TV reports the signal strength, but neither of these devices report the bitrate, so it's hard to tell.

Is OTA better (or worse) than cable in general, or is it case by case?

Regards,
Scott

Hello:

9 times out of 10, OTA is better. Cable (and satellite) generally has to recompress the OTA feed; uncompressing a lossy-compressed feed and then using another lossy compression on it results in more artifacts.

The exception to this is when the station has a direct fiber feed. Stations with a direct fiber feed can use the full bandwidth on HD without the degradation caused by subchannels. Even though there's still recompression to get it into the cable system, because it starts off with less compression, you don't get such an increase in artifacts, assuming they don't compress it more than the OTA is. That's assuming that the cable does compress it down further, which I think they do.

Does that answer your question?

- Trip
post #3846 of 10425
Quote:
Originally Posted by DEEPFRINGEGUY View Post

Here's some info. from a flyer from Antennas Direct:
Satellite Provider: Signal starts out at: 20 mbps; by the time it reaches the dish at the house, it's as low as 6mbps. Same with Cable.
OTA: Signal starts out at 20mbps; and ends up at the house antenna at 20mbps. Highest bitrate available.

- DFGY

Quote:
Originally Posted by DEEPFRINGEGUY View Post

I think it's a big can of worms because there are a lot of variables. Some programs are not very high quality to begin with and when they're broadcast on HD channels they're only as good as the original source. Maybe one of our broadcast engineers will chime in....Can you see a difference?

I don't have cable or satellite, I have OTA. And when I go down to a local resturant or bar and watch the game or I'm in a dept. store watching a cable signal, I see a very big difference. My OTA is far superior.

- DFGY

Your point is good, OTA is generally better than satellite, but calling it "uncompressed" is inaccurate. I've seen HD look like videojanitor's picture on a regular basis. My PBS here in Virginia looks worse than that on a regular basis, because they have their HD compressed down to about 9 Mbps (on average). Just because it's OTA, doesn't automatically mean it's better.

Take a look at Tucson. KUAT is the PBS down there. OTA, the HD comes out in 720p with two subchannels, causing it to be compressed down to about 12 Mbps. Meanwhile, the cable company gets a fiber feed at 1080i at about 20 Mbps. In this circumstance, the cable company is clearly better.

In general, you're right, but it's not an absolute truth.

Quote:
Originally Posted by videojanitor View Post

I also recorded that program using an ATSC capture device, and as I said before, the program was only allowed about 11 MB/s. So although you are correct that OTA broadcasts are theoretically capable of around 20 Mb/s (19.39 Mb/s), that's the payload for the entire stream -- what you actually get for each individual stream is an entirely different matter. In this case, there is only ~11 Mb/s allocated to the main channel.

ATSC capture device? Do you have access to TSReader?

- Trip
post #3847 of 10425
Quote:
Originally Posted by DEEPFRINGEGUY View Post

Hey, thanks for all the great info. that you post. It has been and continues to be very helpful to me.

I'm glad to hear that it's been useful. My DTV channel list is now getting as many as 150 visits a day, and that number keeps increasing the closer we get to the transition date.

Quote:
Originally Posted by DEEPFRINGEGUY View Post

The new rig will definitely bring in Sutro UHF and VHF-HIGH and should do it very well. I really don't get much right now due to the transitional work though. I do get KNTV very well and most of the main Walnut Grove stations and I even get KSBW channel 8 analog pretty well, but, with some snow. But, Sutro is my main source and always has been. I'm getting 7 analog, but I'm temporarily living without 2, 4, and 5, which is tougher than I thought it would be...

I'm kind of surprised that our own Sutro stations are so far behind. I would have expected the Sutro consortium to be one of the first in CA to be finished with all their transistion work...

I'm confident that If everyone moved their digital transmitters to the top of Sutro and upped their power to 1000kw, most of Santa Rosa would have very good reception from Sutro, with the use of a CM-4228, or DB-8. I know that not everyone is planning on increasing their UHF power to 1000kw, but it sounds like Santa Rosa will do pretty well when all the transition work is completed.

There haven't been any changes at Sutro Tower yet. Only during occasional week day hours are stations running lower power. Nights and weekends the stations are all at full power using the antennas they'll use until the fall. The only change you'll see in the fall is an increase in the antenna heights by about 250 feet (on average). Most Sutro stations are running full authorized power now.

The reason for the delay at Sutro is that the tower wouldn't safely hold the weight of all the analog and digital antennas. So they had to put up the temporary light combined antennas for digital until the analog was shut down. Once the analog stations are off the air, all of the old analog antennas will be removed from the top of the tower and they'll be replaced with the new antennas for digital. The temporary digital antennas now being used will then be removed.

For a comparison of what's on the tower now to what will be on the tower as of next fall, look at the tower diagrams on my "Sutro Tower" page - http://www.larrykenney.com/sutrotwr.html

Quote:
Originally Posted by DEEPFRINGEGUY View Post

You know, the only major drawback that I see to "deep-fringe" digital, is that low-flying, small aircraft do tend to (temporarily) disrupt the picture (if they're flying between the my rig and the transmitter) . I wish there was something that could done about that... Analog was also affected, but in a different (much less significant) way. Digital is much more sensitive to this. My local stations are powerful enough that they aren't bothered by aircraft. Perhaps the FCC will allow another kw increase for UHF in the future to help remedy this?
- DFGY

I don't think there will be any increase in power for the foreseeable future. The FCC has set the maximum for digital at 1000 kW on UHF, and I don't think that's going to change.

Larry
SF
post #3848 of 10425
Quote:
Originally Posted by Calaveras View Post

I don't think I've ever posted any of these to AVS forums before. If it wasn't for ham radio I wouldn't have gone to all this trouble.

Chuck

Very impressive, Chuck! That's what I call a beautiful antenna farm.

Thanks for sharing the photos.

Larry
SF
post #3849 of 10425
Quote:
Originally Posted by Trip in VA View Post

ATSC capture device? Do you have access to TSReader?

Why as a matter of fact, yes I do.
post #3850 of 10425
Using the TSReader program on my laptop, it's amazing how little bandwidth is given to HD by some stations. It varies a lot from station to station. I've seen HD programs with only 10 mbps showing for that sub-channel, and I've seen as high as 18.35 mbps.

Channels 5 and 44 with no sub-channels have the highest HD bandwidth, and KQED has the lowest. The last time I checked, KPIX 5-1 had a reading of 18.29 mbps! KQED 9-1 is where I saw the 10 mbps. KGO runs 14 to 15 mbps for their HD 7-1 sub-channel, but running 720p it doesn't seem to be that bad. Look at 7-3 if you want to see what just a little bandwidth will do to the picture. That only gets about 1 to 1.5 mpbs.

Comparing OTA to other services, I don't have cable, so I can't compare Comcast to OTA, but I do have Dish Network and the OTA reception is a bit better. Dish is using that same OTA signal though and recompressing it using MPEG-4, so it's going through a lot more manipulation. If OTA was a 10, I'd give Dish a 9. Overall, I'm very happy with the HD quality I'm getting from Dish, both for OTA channels and the "cable" channels. Channels like Discovery and HDNet look really good!

Larry
SF
post #3851 of 10425
Quote:
Originally Posted by Larry Kenney View Post

Using the TSReader program on my laptop, it's amazing how little bandwidth is given to HD by some stations. [...] Channels 5 and 44 with no sub-channels have the highest HD bandwidth, and KQED has the lowest. The last time I checked, KPIX 5-1 had a reading of 18.29 mbps! KQED 9-1 is where I saw the 10 mbps.

Yep, your KQED experience pretty much echos what I see on a lot of PBS stations, which is what you would expect given that most of them run a lot of subchannels. To my eyes, 10 Mb/s for MPEG-2 720p just doesn't cut the mustard. Heck, that's about as low as I care to go for SD! But, they gotta do what they gotta do ...
post #3852 of 10425
That's very interesting about the weight. I have those printouts of Sutro tower from your site, they're great. That site helped me a great deal in designing my new rig.

Gosh, I hope they don't postpone the transition... That would be very bad for my Sutro signals!


- DFGY
post #3853 of 10425
Quote:
Originally Posted by videojanitor View Post

Why as a matter of fact, yes I do.

Any chance I could convince you to send me some data from Sacramento stations?

If you say yes, I'll provide details.

- Trip
post #3854 of 10425
Quote:
Originally Posted by Trip in VA View Post

Any chance I could convince you to send me some data from Sacramento stations?

If you say yes, I'll provide details.

- Trip

Sure, but I only have the free "lite" version. If that will get you want you want, fire away.
post #3855 of 10425
Quote:
Originally Posted by videojanitor View Post

Sure, but I only have the free "lite" version. If that will get you want you want, fire away.



You have a PM.

- Trip
post #3856 of 10425
Quote:
Originally Posted by Larry Kenney View Post

I'm glad to hear that it's been useful. My DTV channel list is now getting as many as 150 visits a day, and that number keeps increasing the closer we get to the transition date.

Wow! Likewise, great site! Many thanks for maintaining this!

I have one small discrepancy to report. On occasion I can pick up KTLN in San Jose with my CM4228. When I do the TV reports 47.1 as the "virtual channel", not 68.1 as you have indicated in the last station on your list. Maybe someone else can confirm this? Everything else is exactly as you have written.

Regards,
Scott
post #3857 of 10425
Quote:
Originally Posted by DEEPFRINGEGUY View Post

That's very interesting about the weight. I have those printouts of Sutro tower from your site, they're great. That site helped me a great deal in designing my new rig.

Gosh, I hope they don't postpone the transition... That would be very bad for my Sutro signals!


- DFGY

The Senate passed a delay to June 12 today. It's little more than a formality now for the House to pass it and the President will sign it since he requested the delay in the first place. This has to be a fiasco for all the stations on Sutro. Are they actually going to delay the start of the tower work until June? If that happens it could be spring 2010 when you include winter weather delays before the new digital antennas are on top of the tower.

Chuck
post #3858 of 10425
Quote:
Originally Posted by Larry Kenney View Post

The problem for you two-fold: one is that VHF requires a large antenna, one with longer elements, that's too big to have inside, and two, the signals are being blocked by the hills down where you are, so they aren't strong enough to be picked up inside by a smaller antenna.

Your only hope for success is an antenna with some gain up on the roof, like a Channel Master 4228 or one of the new combination high VHF-UHF antennas for channels 7 to 51. I don't think you're going to have much luck with an indoor antenna at your location.

Larry
SF

Thanks...this is a cautionary tale for me to try to find a "magic" indoor antenna, especially if I don't want to fiddle with ordering antennas from specialty outfits and then returning via UPS if the performance is poor. Since I live on the 2nd floor of a 4 story building, I probably won't go for a rooftop antenna on my apartment. (Kind of reminds me of that commercial for cable about the apartment dweller struggling with the satellite dish on his apartment balcony held down with a cinder block). Sounds like I'll have to give up on KNTV. No problemo...the next Winter Olympics are in Feb 2010 at which point I'll have either moved or I'll get a deal on cable.

A general comment / question to the forum, though. Post-transition, in the SF Bay Area, most of the stations (except KGO 7 and KNTV / NBC 3/11) will be UHF. My homebuilt antenna is picking up all the UHF now...even Ion (which are Mt. San Bruno), and this with my temporary laundry-drying-rack-reflector and also the whole thing got mangled when I was cleaning on Saturday. Why don't the stations just all be UHF? Why is it that two of them are going to be VHF?

An even more general comment given the Senate bill on a possible delay in the transition date. The story I read was that it was to deal with the coupon / converter box issue. Where are the media stories about the "antenna issue"? Seems all I see are those ads and "helpful" news features on buying the converter box that the tv newscasters urges us to get the box. Why not a story on the subtleties of the antennas? Even the aircraft issue...in analog I never noticed any problems, but recently a Coast Guard helicopter flew close and the tv cut out for what seemed several seconds.
post #3859 of 10425
Quote:
Originally Posted by GGSkater View Post

Why don't the stations just all be UHF? Why is it that two of them are going to be VHF?

I would have liked to have seen them all on UHF but there's not enough channels to put them all on. I went down my list of digital stations I might be able to receive after the transition and there's only 3 open channels; 11, 22, and 24. As it is, I've got stations on the same channel; KICU and KAZV both on 36. I may end up receiving neither since their heading is only 10 degrees apart. KOVR and KQET on 25. Good-bye to KQET since KOVR is strong. KION and KFTY both on 32 but 90 degrees apart and both over 100 miles away so who knows. And there are more conflicts.

Quote:


An even more general comment given the Senate bill on a possible delay in the transition date. The story I read was that it was to deal with the coupon / converter box issue. Where are the media stories about the "antenna issue"?

A lot of people have asked this question as it is an overlooked issue.

Chuck
post #3860 of 10425
Quote:
Originally Posted by GGSkater View Post

Why don't the stations just all be UHF? Why is it that two of them are going to be VHF?

The biggest reason is probably because VHF needs less transmitter power for comparable coverage, so the station(s) use smaller transmitters and save a lot of money on electricity. So, it seems that almost any station that previously was on channels 7-13 has elected to use that for their post-transition digital channel. Most on channels 2-6 will not be going back to those channels, as there are noise and interference issues that can wreak havoc with digital.
post #3861 of 10425
We moved to California in 1966. In all of that time, the best television signals have come from Sacramento's channel 10 and 13. The best reception from S.F. and San Jose stations has been channels 9 and 11, with KGO close by. 11 wasn't always good.

VHF-HI is great band to broadcast television in. It works better.
post #3862 of 10425
Quote:
Originally Posted by Trip in VA View Post

Hello:

9 times out of 10, OTA is better. Cable (and satellite) generally has to recompress the OTA feed; uncompressing a lossy-compressed feed and then using another lossy compression on it results in more artifacts.

The exception to this is when the station has a direct fiber feed. Stations with a direct fiber feed can use the full bandwidth on HD without the degradation caused by subchannels. Even though there's still recompression to get it into the cable system, because it starts off with less compression, you don't get such an increase in artifacts, assuming they don't compress it more than the OTA is. That's assuming that the cable does compress it down further, which I think they do.

Does that answer your question?

- Trip

Yes, it does! Thanks for the reply!

Eventually, after the transition, I will probably move, or split, the antenna feed from my TV to my Tivo HD so I can record programming from both sources, OTA and Comcast. Although, I image the Tivo probably compresses the HD signal even more before it stores or displays the recording. For now I figured the *best* possible signal would be directly from the antenna (with no splitters) directly into the TV, bypassing the Tivo altogether.

Personally, I can't tell the difference between the Comcast program through the Tivo and the OTA broadcast directly to the TV. If I flip back and forth during a HD news broadcast, so something similar, they both look really nice on my 42" plasma.

Regards,
Scott
post #3863 of 10425
Quote:
Originally Posted by TPeterson View Post

Of the locals that I've looked at, only KQED's Comcast feed is different from their OTA signal. The Comcast KQED-HD feed is actually higher bitrate than their broadcast version by about 3-4 Mbps. For the others, the two versions seem to be identical.

Just currious... What are you using to measure the bit rates?

Thanks for the reply!

Scott
post #3864 of 10425
Scott--

I'm 99.9% certain that your TiVo does absolutely no processing of the DTV video streams that it gets from any source before recording them to HDD. What you see is what it got.

I use TSReader (Lite) to examine recorded DTV transport streams of interest.
post #3865 of 10425
Quote:
Originally Posted by scottndsky View Post

Wow! Likewise, great site! Many thanks for maintaining this!

I have one small discrepancy to report. On occasion I can pick up KTLN in San Jose with my CM4228. When I do the TV reports 47.1 as the "virtual channel", not 68.1 as you have indicated in the last station on your list. Maybe someone else can confirm this? Everything else is exactly as you have written.

Regards,
Scott

Thanks for the compliment on the web site.

As for KTLN, they're not sending out the correct PSIP station ID information. According to FCC rules, stations must identify their stations on PSIP so that their virtual channel number is their analog channel number, even after the transition and the analog transmitters are off the air. KTLN is not sending any information to show their ID at channel 68-1, as they should be. I don't think they're sending any ID at all.

On my new Sony tuner they come in on channel 47-3, on my old Sony tuner they come in on 47-1 and on my digital to analog converter box, I get a strong signal on channel 47, but "No Signal" is indicated.

I've written to them about the problem, but it doesn't seem to matter that they're breaking the law.

Larry
SF

P.S. This FCC rule is why KCSM changed their ID from 43 to 60.
post #3866 of 10425
FYI... with the Senate passing the bill to delay the transition unanimously, the House will undoubtedly pass it (probably today) and President Obama will sign it, since it was his idea, among others, for the delay.

In the Senate bill, stations have the option to turn off their analog transmitter and make changes earlier than June 12, if they want, but as a local Chief Engineer wrote to the SF HD Yahoo group: "For the most part, the broadcasters want to switch, but it's going to be difficult to do here in the SF Bay area unless all the critical channel swaps between here and Reno can be coordinated at the same time."

What's going to happen on February 17th? We'll have to wait and see.

KOFY has already reported to the FCC that they will be turning off their analog transmitter on channel 20 on February 17 and going strictly digital on channel 19. I haven't seen anything from any of the other Northern CA stations yet.

Larry
SF
post #3867 of 10425
Quote:
Originally Posted by TPeterson View Post

Scott--

I'm 99.9% certain that your TiVo does absolutely no processing of the DTV video streams that it gets from any source before recording them to HDD. What you see is what it got.

I use TSReader (Lite) to examine recorded DTV transport streams of interest.

Awesome! I didn't realize that! I like this Tivo HD even *more* now! ;-)

Other's are saying the same thing:
http://tivocommunity.com/tivo-vb/sho...6918&p=6738220

Regards,
Scott
post #3868 of 10425
Quote:
Originally Posted by Larry Kenney View Post

In the Senate bill, stations have the option to turn off their analog transmitter and make changes earlier than June 12, if they want, but as a local Chief Engineer wrote to the SF HD Yahoo group: "For the most part, the broadcasters want to switch, but it's going to be difficult to do here in the SF Bay area unless all the critical channel swaps between here and Reno can be coordinated at the same time."

Larry
SF

Between SF and Reno?? Why would that be? There isn't any overlap in coverage between the two markets. I can barely detect a couple of the Reno analog stations here with channel 11 being the only one that ever syncs a picture. I've never received a Reno digital station.

I hope all the Bay Area stations go off on Feb. 17 so the tower work can begin.

Chuck

Edit: I went through the whole list of Bay Area stations and they all are either already digital on their final channel, are returning to their analog channel, or are going to use an analog channel already in use in the Bay Area. It doesn't seem like any further coordination should be required.
post #3869 of 10425
Quote:
Originally Posted by Calaveras View Post

Edit: I went through the whole list of Bay Area stations and they all are either already digital on their final channel, are returning to their analog channel, or are going to use an analog channel already in use in the Bay Area. It doesn't seem like any further coordination should be required.

The only coordination needed is that they all agree to go, otherwise it won't work.
post #3870 of 10425
I'm in an area of Vallejo, I only get Analog Ch.10 & 13 from Sacramento, I can't get those stations in Digital
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