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# Indianapolis / Terre Haute / Lafayette, IN - HDTV - Page 7

Tom,

I noticed 8-3 has been taken off the Digital Transmission. Is this permanent or temporary? I noticed that the radar did not appear to be working this past weekend. Is this because of that? or maybe is it related to the Breakup issue during high chroma scenes?

Thanks!

Greg

### Gear mentioned in this thread:

Regarding the UHF and VHF power issue:

(This is not meant to be a rigorous engineering explaination, but meant to help the non-techies to have an idea as to why UHF TV broadcast stuff needs so much ERP.) There are reasons other than antenna physics for higher power, like the more 'straight' and more mirror like propagation characteristics at UHF, but I assume that everyone already understands that UHF is GENERALLY more limited to line of sight than VHF.

The energy being transmitted through the air can be measured in terms equivalent to 'volts per meter.' This 'volts per meter' represents conceptually an energy density because the impedance of free space is constant. Also, the 'volts per meter' can be sensed by a given length of antenna wire, where a longer antenna can sense more voltage -- EXCEPT: when transitioning between free space and an antenna wire, the impedance match isn't always very good. If you have an antenna that senses 1volt, but the impedance is 1Mohm, then the available signal power is much lower than if the antenna impedance is somewhere between 75 and 300 ohms or so. When 'matching' is practical, some of the effects of mismatch can be mitigated, but then there are also losses and sometimes frequency response variations (not all impedance is resistive, and dealing with resistance, reactance across wide frequency ranges is fun, challenging, interesting, and best avoided!!!)

Magically, at a specific frequency, certain lengths of wire in a dipole antenna (for example) will maximize this impedance match, and provide more energy transfer at the interface. Certain wire lengths will tend to maximize the available current for a given voltage sensed at a given frequency, and this impedance is often between 50 and 300 ohms depending upon the antenna architecture. (AFAIR, the impedance of free space is about 377 ohms (120 * pi), so when you have a certain
field strength measured in volts per meter in space or air, you have a representation of power also -- IN THIS CASE.)

Some antenna lengths will maximize the transfer, and some lengths will minimize the current (therefore act poorly.) For UHF, the ideal wire lengths for a dipole antenna are very short when compared to lower frequencies. That small antenna will capture less voltage for a matched antenna, because it is just physically shorter. You can use a longer antenna, or an antenna with larger capture area (essentially a different architecture that usually has gain and directivity), but the side-effect is greater directivity, sometimes in the wrong directions.

For point to point applications, well designed antennas that have alot of directivity at UHF or higher have little disadvantage, and in fact, have significant advantages in certain cases. For 'broadcast' applications like UHF TV, the receiving antenna that has a large signal collection area will also be directional. For the transmitting antenna, the directivity is often in the VERTICAL direction (generally towards the horizon), but the practical limitations to the antenna gain are associated with the usual desire for coverage in all horizontal directions. It is likely that even with transmitting antennas with as much gain as practical, the transmitters at UHF need more power to compensate for less antenna 'efficiency' (terminology misused, but conceptually correct.)

Similar to there being practical limitations for transmitter antenna gain (e.g. you don't want to use a 2 degree dish that provides huge gain, but very constrained signal delivery region), there are also practical constraints on receiving antenna designs (e.g. you can theoretically use a VHF dipole on UHF frequencies, and it will indeed capture more signal, but the directional characteristics for that multi-wavelength dipole are suboptimal in most cases.) A better 'large capture area' antenna for UHF TV reception would likely be a Yagi, log periodic or bowtie (depending on application and installation.)

In a way, the 'antenna gain' for a UHF antenna in some cases is necessary to overcome less signal capture from the dipole (or isotopic) at that frequency. Conceptual example (but maybe not totally correct), a dipole antenna at 10MHz with 0dB gain would capture a similar strength signal as a moderate gain antenna of 16dB at 400Mhz.

Again, this is 'conceptual', but the signal capture ability of an antenna is very much influenced by its size, no matter the frequency.

A most exaggerated example might be a 'dipole' for 10GHz (it is very small), which would be nicely matched at its design frequency -- providing the typical antenna impedances that we are familiar witih. From an intuitive standpoint (and this time, intuition is correct), that 10GHz antenna, however well matched, will provide a relatively small signal output for a broadcast-type signal, when compared to a 10MHz dipole being used at the front end of a 10MHz receiver.

For UHF and higher, the ability to use 20dB gain antennas on both the transmitter and receiver, for point to point applications, allows transmitter
power to be concentrated, and the 'gain' (directivity) on the receiver side have significantly different characteristics than using 0dB gain on both transmitter and receiver side at perhaps 10MHz.

In the case of 'point to point', where BOTH antennas can be very directional and have high gain, UHF communications can be implemented with rather nice, low powers. For essentially omni-directional broadcast applications, one should expect to need higher ERPs at UHF than at VHF,
even if not in challenging propagation conditions.

John
Jim Hunt/Kokomo

You must mean you have no trouble with any Indy station. Do you get ch 56? It only runs a bit over 400w my direction from 28 miles and I have trouble getting much of a signal. This station is directional toward Bloomington. Ch 53 is fine from the same site with 10db more power.
We're having trouble with the radar right now anyway, no sense in broadcasting a non-functioning radar. And I figured I'd just assuage the concerns that the radar was causing the breakup. It's not. In the process I did discover that my "slack" bandwidth was a little low. But it's not that, either.

Another testing opportunity (?!) scheduled for roughly 5:40 pm Thursday.

Tom Weber
WISH Engineering
Tom,

Thanks for the update!

Greg
Quote:

Originally posted by larryv
Jim Hunt/Kokomo

You must mean you have no trouble with any Indy station. Do you get ch 56? It only runs a bit over 400w my direction from 28 miles and I have trouble getting much of a signal. This station is directional toward Bloomington. Ch 53 is fine from the same site with 10db more power.

I guess I was overstating my previous comment. I do not receive 53 or 56 nor was/am expecting to at this point. Sorry for not clarifying.
Quote:

Originally posted by Tom Weber
We're having trouble with the radar right now anyway, no sense in broadcasting a non-functioning radar. And I figured I'd just assuage the concerns that the radar was causing the breakup. It's not. In the process I did discover that my "slack" bandwidth was a little low. But it's not that, either.

Tom Weber
WISH Engineering

Thanks for working on the break-up issue and sorry for hammering you (channel 8) about haveing to many sub-channels. I did see some break ups last night watching CSI and Without a Trace and even noticed one during the M-Life commercial when the entire picture was pale light blue all over.

I noticed you seem to be switching back and forth between HD for the show and upconverted HD/widesceen for some commericals and newsbreaks. Am I correct or am just crazy?
Source of breakup has been found, but it may be a few days for a fix. We'll have to calibrate several items in a critical chain that can't be disrupted too much. But it's coming.

That wasn't a hammer - just a friendly poke in the ribs . And if I hadn't looked at the issue, I wouldn't have found my "slack" was a bit too low, so I think you actually did me a service.

After all, if I didn't have people clamoring for my product, I wouldn't have a job!

Switching back and forth can be confusing. When CBS sends stuff that isn't 16:9, we do the upconversion here so that we can stretch the picture to fill 16:9 screens. But CBS, when they send 16:9 shows, still send commercials in 4:3 since they don't believe in stretching. As a result, I have to think hard about whether these things, and I supposedly know what we're doing!

Regards,
Tom Weber
WISH Engineering
Tom, you always pass along the info we want and are looking for. I'm glad that we can help you out from time to time too.

Question I have is, where are the other networks engineers, do they pay attention to us as well?
I've seen at least 3 other stations' engineers on AVS. And remember, just look at the number of readers vs. the number of posters on a topic - there are tons of lurkers, and they may well include the people from the other stations.

Regards,
Tom Weber
WISH Engineering
Ok well if that is the case, HEY WTHR IM HAVING TROUBLE WITH YOUR PICTURE QUALITY.

When I'm watching any fast movement it's like I'm back in college, the picture seems to have tracers. For instance when watching Wheel of Fortune the movement of the wheel seems to have a shadow that follows behind the wheels movement.

I don't know the correct terminology for this but it only happens, or most frequently happens on WTHR.

Anyone else have this issue?
I am seeing the exact same problems with WTHR. It is like a slow-motion-ghosting-smeared image that following moving images around. More noticeable with faster moving objects. You are not alone on this. Was wondering if it was just me. Glad you mentioned it.
On the WTHR problem, is this showing up on up-converted programming only, or on both up-converted and true network 1080? I don't really watch much WTHR-DT, so I haven't seen this problem.

Ken
I have seen this, but only on the upconverted programs... Hope that Helps!

greg
While on the subject of WTHR-DT, has anyone else noticed that during HD programming from NBC, there is a subtle but constant shifting of the tint in colors, especially flesh tones? It changes back and forth from a little too red to correct and then a little too green. I only notice this situation on this station and only during NBC HD programming.

Steve
I think the shadow is more on the upconverted show's than true HD. What ever the problem is, it is anoying and I hope that it is being looked at.

I haven't noticed the color fluctuations, however I have seen a problem lately with ER and what seems like colums of pixels being vertically shifted out of alignment.

I watch more WTHR than any of the other networks.
Quote:

Originally posted by goldrich
While on the subject of WTHR-DT, has anyone else noticed that during HD programming from NBC, there is a subtle but constant shifting of the tint in colors, especially flesh tones? It changes back and forth from a little too red to correct and then a little too green. I only notice this situation on this station and only during NBC HD programming.

Steve

Yes I have noticed this as well.... What type of OTA receiver are you using ? I have a Zenith 420. I have also Noticed the Column effect on ER. This doesnt really bother me though cause the only thing I really watch on WTHR is Leno... and that is only when I can stay up that late...lol

Greg
Greg,

I'm using the RCA DTC100. I've noticed this color shifting on ch. 46 for some time now. I'm glad someone else has noticed it, too. Thanks.

Steve
Re: the WTHR color shifting --

Good, it wasn't my imagination. I know that I have seen it on my DTC100, but also probably the STR165.

The color shifting is really odd.

John
WTHR should really look into fixing the issue. It is really starting to drive me crazy. While watching the news tonight some video of a BB game just about made me sick there was so much distortion.

Anyone know someone there we can contact?
Did anyone get really bad signal loss tonight on 8.1. All of the other digital channels are in the 80-90 range but 9 is floating around 40-50.
Quote:

Originally posted by fgr41
WTHR should really look into fixing the issue. It is really starting to drive me crazy. While watching the news tonight some video of a BB game just about made me sick there was so much distortion.

Anyone know someone there we can contact?

On WTHR's web site, there is a contact form that you can fill out, directing it to the department you want. I recently sent them an inquiry about their "MobileTrak" unit, and received a reply back within a couple of days.

Ken
Newbie question....how can you tell whether a digital broadcast is formatted in 1080i or 540p? I live in Indy and just hooked up an HDTV receiver but am not as impressed as I thought I'd be with the results. For example, the show Ed on NBC last night claimed to be in HDTV but it really only looked like DVD quality (nothing to sniff at...but still not the vivid quality that I was expecting for an HDTV broadcast). Anyhow, I checked the local affiliate's website and it basically just regurgitated a list of shows that NBC is offering in HDTV (including Ed)...but isn't up to the local affiliate (WTHR) whether they will actually broadcast in 1080i?
First off I have never heard of 540P. Most of the locals are not doing true 1080i, rather 720P which is then upconverted by most STB's to 1080i. If you want to see good quality HD 1080i check out 20.1 the PBS HD loop is great for seeing what it can do. Shows like ED are in better quality than standard def but I am not sure what they are really sending down.
Thanks for the info FGR (BTW...I meant to say 480p...I think 540p is what DVD is formatted in). Unfortunately, it seems that my indoor antenna isn't powerful enough to receive the PBS HD channel. I guess I'll have to look into installing an outdoor antenna. My local cable company (Insight) just started providing "HDTV" programming but I heard that it's really just DTV because Insight won't provide the necessary bandwidth to the network affiliates. Has anyone heard whether there is any truth to this?
Quote:

Originally posted by fgr41
[b]First off I have never heard of 540P. Most of the locals are not doing true 1080i, rather 720P

Huh? I thought everyone except ABC and Fox were broadcasting 1080i. Most of the "HD" shows I've seen on NBC look pretty fuzzy except for Leno, the 02 Olympics, and the one live NBA game NBC borrowed from HDnet. I think other NBC stuff is not very sharp because it is transferred from film or not recorded with true HD gear.

What is the native resolution of your HDTV / projector, 720p or 1080i? If 720p you are kind of having the opposite problem of what you described. If 720p (projector/flat panel), all the 1080i stuff is being converted to 720p which will cause it to not be quite as sharp. Personally I think the ATSC should have only defined one format for HD. It should have been progressive so we could eliminate the conversions, confusion, and everyone would see nearly the same HD. For cost reasons they couldn't do that though (1080i is cheaper to make).

On my 1080i Mits HDreadyTV, nothing has matched the quality of HDnet (1080i on DirecTV). With HDnet scored a 10 and old analog 480i NTSC as a 1.... Some of the CBS shows, some HBO/SHO, and PBS are close but not as good, I'd give them a 9. Because of the conversion in my tuner, ABC never looks quite as good, they're an 8 probably. A good progressive scan DVD is about a 6. The best stuff on Fox I'd give a 5, the worst stuff a 2 or 3 (some of the widescreen sports don't look good at all to me).

540p is one of the formats defined by the ATSC (540p is not HD). If you look through the HTPC forum here at AVSForum, you'll see a lot of people making PC's that will output 540p, DVD players are limited to 480p. My luck with HTPC hasn't been that good.

Quote:

Newbie question....how can you tell whether a digital broadcast is formatted in 1080i or 540p?

Some of the TV's/Tuners will tell you what the incoming signal is. My Philips (same as Hughes / Mitsubishi / Toshiba) set top box does not tell the input format unfortunately, it just converts everything to 1080i. My friends Mits TV with OTA HD tuner builtin does tell you the incoming format right on the screen underneath the channel.

Definitely use the feedback/email/complaint forms on the websites of all the stations. They need your input to make HDTV better. Give constructive criticism, tell them where you are, your signal strength, and what gear you have.

Kevin
Quote:

Originally posted by kwerner
Huh? I thought everyone except ABC and Fox were broadcasting 1080i. Most of the "HD" shows I've seen on NBC look pretty fuzzy except for Leno, the 02 Olympics, and the one live NBA game NBC borrowed from HDnet. I think other NBC stuff is not very sharp because it is transferred from film or not recorded with true HD gear.

I believe some stations are actually doing 720P for instance ABC uses 720P instead of 1080i. Even the stations that are using 1080i most of the content is not native 1080i so they are having to upconvert it which gives you a WS picture but not the stunning quality that HDNet does. Many believe that 720P give better picture quality than 1080i. http://www.jonasjensen.com

Quote:

Definitely use the feedback/email/complaint forms on the websites of all the stations. They need your input to make HDTV better. Give constructive criticism, tell them where you are, your signal strength, and what gear you have.

Kevin

Good point, let them know we are here and what we think. The more feedback they have from us the better the quality of the programming. I hope anyway
Thanks for the feedback Kevin and FGR. To answer a couple of your questions, my RPTV is a Pio SD533 (w/ native format of 1080i) and I'm using a PC HDTV tuner card (MyHD).

I'll voice my dissatisfaction with the local affiliates...but it'd carry more weight if I had evidence that their advertised "HD" programming is actually just DTV or an upconverted DTV format (if this is possible). If I just complain that the shows that I'm watching are "fuzzy" then they will probably just make the excuse that it's a hardware problem at my end or that I'm being too particular about the quality of the picture. I WANT MY HD-TV!!!
I have service through Insight Cable in Fishers, IN (Indianapolis market). I've had the HD STB for a couple of weeks now, receiving HBO-HD, SHO-HD, ABC-HD, and CBS-HD. The premium stations look incredible, but the local networks are hardly worth watching. The signal from CBS cuts out all the time, and looks just as good, if not better, while watching through the standard DTV STB. Watching "America's Funniest Videos", I notice that the studio shots of the host have a quite a bit of blur, probably from the up-conversion of the show. The videos look fine though. I've also noticed that both local stations seem to have a lot of "jitter" during news broadcasts. It's hard to describe what is going on, but it looks like the image jogs up and down on the screen very quickly whenever a bright color or pure white is displayed. It tends to give me a headache if I watch it for two long. It is most noticeable during the news broadcasts when a graphic is displayed.

Lately, we've used the HD box to watch the premium stations, but switch back to the DTV box for local stuff. Anyone else in the Indy area with Insight notice the same behavior?
Is anyone else having trouble with the subchannels on WISH-DT? I'm using a Samsung SIR-T165 HD tuner, and ever since 8-3 was added back in to the lineup several days ago, tuning to either 8-2 or 8-3 causes the tuner to reboot. On 8-2, the tuner will reboot once and then work properly. On 8-3, the tuner will reboot repeatedly and indefinitely, never displaying an image. I don't care too much about radar, but I'm concerned this problem will carry over into any NCAA multicasts that might be coming soon.
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