ATSC 3.0 WTTK (RF15) Indianapolis, IN

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NatHillIV
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ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by NatHillIV »

WTTK - CBS (RF 15) officially switched over to ATSC 3.0 Tuesday, August 10 2021, at around noon.
That was the day scheduled for the transition.
The channels transmitted include 5001 - 159.1 WXIN, 5002 - 129.1 WTTK, 5003 - 106.1 WRTV, and 5004 - 113.1 WTHR.
For some odd reason, when WTTK was ATSC 1.0, I would get great numbers and reception from WTTK for weeks, then it would suddenly go away for weeks. Not sure if it was weather or just what.
WTTK is liisted as a Kokomo station, but FCC maps show that it should reach my home in Bloomington. Hoping that things get better, but I'm currently disappointed. I almost always get rock solid ATSC 1.0 signals from stations transmitting far weaker signals from the same antenna farm in Indianapolis.
Anyway, apparently I am now officially on the 'ragged edge' of ATSC 3.0 reception. Signal level @ 100%, but signal quality at about 50%, and Emby reports all sorts of dropped frames. Must admit my old eyes generally can't see them. But every once in a while, the picture will freeze up or pixelate on the HDHomeRun app..
I only get sound with the HDHomeRun app on Windows 10 after a $.99 purchase of an HEVC extension from Microsoft tells me many aspects have got to improve dramatically before ATSC 3.0 gets anywhere near general public use. Kudos to Silicon Dust (or maybe Microsoft) for walking me through the purchase. That was easy.
Maybe ATSC 3.0 can be used to load firmware on cars or something else fabulously useful to the general viewing public.
But for the moment, I'm not terribly impressed.

W9MDO
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by W9MDO »

Hi - I'm in Noblesville, and all four ATSC-3.0 signals seem to be coming from the same location, and have the same reported signal strength. I get good video on the PC and Android apps, but no closed captioning. My Roku TV's with the current HDHR4K app don't work at all on ATSC-3.0. I hope SiliconDust will remedy these bugs.

I do see the difference in picture quality here. What bit rate are you seeing? Mine are showing about 5.2MB/S. At this point, most all of the content is upconverted HD, but early next year we should start to see true 4K content.

xmguy
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by xmguy »

Just curious. What are the modulation schemes/PLPs used?

Thanks

NatHillIV
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by NatHillIV »

I'm not on the ragged edge any longer.
I'm apparently in the middle of nowhere, at least my tuner thinks I am!
When I could actually receive a signal, HDHomeRun Config gui reported the signal was QAM 256K.
Sure wish it got out better. The pictures looked really good for the few hours I got it.
All four signals come from the same antenna and RF15 that used to transmit WTTK and a pair of sub-channels.
They 'farmed out' the ATSC 1 signals to other stations/transmitters in Indianapolis.
I personally think at the end of all this, the only use for ATSC 3.0 will be to allow stations to cram together more signals on one frequency (as they've done with WTTK), which will allow stations to sell their frequency to cell phone companies in another get-rich-quick auction.
Not an industry insider, but that's my foggy crystal ball prediction.

NatHillIV
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by NatHillIV »

ATSC 3.0 RF 15 is coming in well this morning. WRTV (one of the four HDTV feeds) is HEVC @ anywhere from 3 to 6.9 bitrate.
Picture is really good, but Emby reports all sorts of dropped frames. My old eyes can't see anything wrong.
Sure wish WTTK could up the power just a LITTLE.

kyl416
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by kyl416 »

They can't. They already took advantage of the maximization window to increase their power to 450 kW from their originally assigned 398 kW, but they couldn't increase it any further as it would cause more than 0.5% interference to WXIX in Cincinnati and more than 2% interference to upper-adjacent WDNI-CD.
Last edited by kyl416 on Sat Aug 14, 2021 6:38 am, edited 1 time in total.

sdust
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by sdust »

kyl416 wrote: Sat Aug 14, 2021 6:29 am They can't. They already took advantage of the maximization window to increase their power to 450 kW from their originally assigned 398 kW, but they can't increase it any further as it would cause more than 0.5% interference to WXIX in Cincinnati and more than 2% interference to upper-adjacent WDNI-CD.
I am curious how is FCC coming with these numbers - 0.5% or 2% or how bureaucracy meets real life. ;)

kyl416
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by kyl416 »

It's in the TVStudy they submitted with their application to increase the power back in 2018. You can't cause more than 0.5% interference to full power stations or more than 2% interference to low power or Class A stations. It also takes into account the affected population of those areas receiving interference.

It's based on stable reception conditions, if they were able to take unpredictable real world effects into account like knife edge diffraction, atmospheric boost, etc, in most cases the interference would be worse than what TVStudy predicts, and they wouldn't have been able to get that increase.

sdust
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by sdust »

I am having trouble reading the study.
Is IX interference?
Why so many scenarios?
Wouldn't it be sufficient to present only the worst scenario? Bureaucrats clearly like paper. ;)

Image

Please explain how do we get 0.48 for the New IX here.

jasonl
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by jasonl »

IX is interference. The percent change is the same as calculating the percent change in anything, take the difference between the numbers and divide by the original. (1626482-1618640)/1626482 = .0048, or 0.48%.

sdust
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by sdust »

jasonl wrote: Sat Aug 14, 2021 1:48 pm IX is interference. The percent change is the same as calculating the percent change in anything, take the difference between the numbers and divide by the original. (1626482-1618640)/1626482 = .0048, or 0.48%.
This doesn't make sense. Every time you do a study you can make a new 0.5% of the population get interference? ;)

What's the meaning of Percent column, it clearly stays below 2%.

Also what about the new census? Do all the studies need to be redone now?

NatHillIV
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by NatHillIV »

PROBLEM SOLVED - Or at least I've made a diagnosis as to why my antenna performed so poorly on ATSC 3.0 WTTK.
When I went out to hook up the antenna directly to my Silicon Dust 4K receiver to see if the problem was added somewhere in my system, I just happened to notice that when I raised my antenna several months back, I had placed it pretty much in a direct line with a power line leading to a transformer at the barn.
Well, just for kicks, I took another similar winegard antenna, put it on the roof, ran the front end through the tower for support, and hooked the receiver up to it. Probably lower than the normal antenna by 8 feet or so, and no doubt looking through the tower didn't help much. With that odd-ball setup along with quite a bit of reduction of signal strength (no preamp), the receiver had no problem locking in to the ATSC 3.0 signal.
I have to believe that when I either lower the antenna or add another antenna somewhere else whose only job is to receive WTTK ATSC 3.0, I should be all good.
Sorry for the confusing information that led to all the discussion. Will let everybody know how rock solid the signal becomes (as I suspect it will) when I get away from the power line and add a decent preamp to help the Silicon Dust 4K receiver.
Aw, the joys of antennas and their problems when a dufus is involved! :shock:
for laughs.......... https://photos.app.goo.gl/aV5vhWn2vnHFWa926

NatHillIV
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by NatHillIV »

The plot THICKENS. Rick Poling, the engineer at WTTK and a few other Indy stations, was nice enough to look into my situation, and smart enough to bring up the possibility that radio station WREP, a low power station (200 watts I think) located at Martinsville High School might be an issue. WREP is pretty much in a straight line with WTTK, both broadcasting at RF15. In all likelihood, my problems are due to WREP being just strong enough to mess up WTTKs signal. When I lowered the antenna, Rick's theory is that I was in fact letting trees block the signal from WREP. I'm kind of surprised WREP is still on the air, but I think I can add another antenna located much closer to the ground and get WTTK's signal to work.
Never a dull moment with antennas, is there!
The good news is that I THINK when I get it all sorted out, I will find that ATSC 3.0 gets out the same distance as WTTK ATSC 1.0 did, which is what Rick is aiming for.

jasonl
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by jasonl »

sdust wrote: Sat Aug 14, 2021 6:15 pm
jasonl wrote: Sat Aug 14, 2021 1:48 pm IX is interference. The percent change is the same as calculating the percent change in anything, take the difference between the numbers and divide by the original. (1626482-1618640)/1626482 = .0048, or 0.48%.
This doesn't make sense. Every time you do a study you can make a new 0.5% of the population get interference? ;)

What's the meaning of Percent column, it clearly stays below 2%.

Also what about the new census? Do all the studies need to be redone now?
The first number in each pair is area in square miles, the second number is population within that area.

For maximization, stations that are operating below the maximum power output for a given frequency are able to boost up to match the coverage area for the largest station in the market or the maximum power for the frequency, whichever is lower, as long as they don't generate any more than the permissible interference to any other station.

sdust
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Re: ATSC 3.0 WTTK (RF15) Indianapolis, IN

Post by sdust »

jasonl wrote: Mon Aug 16, 2021 7:48 pmThe first number in each pair is area in square miles, the second number is population within that area.
This is kind of obvious and can be gleaned from the data easily. The interesting part here it is the population and not the terrain that is taken into account. A lot of leeway here.

For maximization, stations that are operating below the maximum power output for a given frequency are able to boost up to match the coverage area for the largest station in the market or the maximum power for the frequency, whichever is lower, as long as they don't generate any more than the permissible interference to any other station.
This still does not answer my question - where does the Percent come from and does it need to stay under 2%?
The New IX seems relative not absolute. It is strange.

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