DTV & Bad Weather

[wajobu]

This was a HUGE oversight in the development of this new and improved service--big problem...having broadcast dropouts when they are needed most.

[Jeffhs]

Originally Posted by AUdubon5425

Well, I've been experiencing some very severe weather for a couple of hours now. This is the first time I've been able to witness what a DTV OTA signal would look like during high winds and severe thunderstorms.

I am using rabbit ears, which have pulled in strong signals with no problems. Well, as soon as the thunderstorms hit the DTV signal went to absolute crap. I'm very disappointed, and thankful I still have analog to fall back on during this flooding and tornadic activity.

It really surprised me how bad the signal deteriorated, considering I'm less than two miles from the transmitter tower of the station.

Thank God we still have power - I've had a fever for 3 days and am having to stay up to monitor the flooding.

I didn't realize you were having problems with floods and tornadoes at the same time North Dakota is in the middle of a major flood.

As far as DTV signals being unusable in inclement weather goes, I'm not surprised, as many stations are not yet transmitting at full power on their DTV channels. However, if you are that close to the New Orleans TV transmitters, you should have much more signal than you need for excellent reception, even with rabbit ears.

Since I (and most other folks here) have cable, I'm not concerned about loss of signal in bad weather. (The cable company, however, does pick up the digital signal [they no longer pick up the stations' OTA signals via antennas], which is in turn fed to the cable system via fiber optic lines; the digital ATSC signals are converted to 4:3 NTSC on an as-needed basis.) However, for those folks in my town who are still using rabbit ears or outdoor antennas (there are still a few here, though most of us have either cable or satellite), I don't know. I do know that in my case, I get only one channel on an antenna well enough to watch (CBS channel 19), and the NBC affiliate on channel 3 doesn't reach here at all; the other five channels are fair to poor at best. I know of at least one other situation where channel 3 isn't watchable here; that is the grocery store three blocks from me, which has a Magnavox TV they used to use during football season. That set didn't get channel 3 on an antenna, either, so they got cable for a short time; however, the cable service has long since been disconnected.

But I digress. My point is that the village in which I live is some 40 miles from the Cleveland TV stations, which transmit from a southwestern suburb of the city, and analog reception is awful, as I mentioned above. Heaven help those few folks here who are still using antennas come 06.12, as digital reception here is probably iffy at best, except as I said for CBS channel 19. Without cable or satellite, these folks will be up the creek during inclement weather conditions as far as reception of digital TV (or, more accurately, the lack of it) is concerned. I suspect Time-Warner Cable, not to mention Dish Network, will have a few more installations to do in this town before June 12. I can envision this village being almost 100 percent wired for cable in the near future; it's close to that point already.

As has also been mentioned in other posts, radio is not the best medium for emergency information (the Emergency Alert System notwithstanding), as weather radar cannot be seen in radio weather reports. All we can hope is that the TV stations get their full-power DTV signals on the air by June 12, but even then there will be some dead spots where, given DTV's all-or-nothing nature, OTA reception may be iffy or downright nonexistent.

[AUdubon5425]

Originally Posted by Jeffhs

I didn't realize you were having problems with floods and tornadoes at the same time North Dakota is in the middle of a major flood.

Yep, and we're getting another round tonight. Incidentally, I lived in Fargo-Moorhead for a couple of years - really disheartening to see the predicament they're in.

Originally Posted by Jeffhs

However, if you are that close to the New Orleans TV transmitters, you should have much more signal than you need for excellent reception, even with rabbit ears.

The transmitter is about a mile away as the crow flies. That's what disappointed me so much about the signal problems. I have cable in the living room, which has a lot of windows, and with the 50+m.p.h. winds I moved into the bedroom which has no cable because I'm not going to rent another cable box.

Originally Posted by Jeffhs

As has also been mentioned in other posts, radio is not the best medium for emergency information (the Emergency Alert System notwithstanding), as weather radar cannot be seen in radio weather reports. All we can hope is that the TV stations get their full-power DTV signals on the air by June 12, but even then there will be some dead spots where, given DTV's all-or-nothing nature, OTA reception may be iffy or downright nonexistent.

A secondary gripe is that my battery-operated TV's will be useless if power is lost this hurricane season. Last year after Gustav I was without electricity for a week. At least we DO have radio to fall back on.

[Yamahalic]

I am an early adopter with digital TV tech, and yes it does have some issues, but in general it is WAY better than analog. I stated out around 5 years ago (I wanted to see the Olympics in full HD) with a 60" widescreen HDTV (i.e., analog not so good at this size), and I purchased a Digital Tuner/DVR unit (like Tivo, but no monthly fee) to go along with it. I have no pay TV, only free off-air stuff, with free TV Guide On Screen. I like free, free is good (o-k, I had to buy the hardware, but at least it is a one time charge).

The first thing you learn is that digital signals are all transmitted on UHF (so in my case for example, channel 66-1 digital is really the digital version of analog channel 13, aka. 13-1). And, since you now will need to pick-up UHF reliably, you best get the correct antenna for your location. Here is a link to help you figure what antenna you need.

http://www.antennaweb.org

In my case, I needed the strongest available (10" long), and even that one needs to be pointed in the correct direction or else you will lose some stations. On a clear day, I am getting around 60 digital stations (mix of english and various foreign language stations) because of multicasting (i.e., because of digital tech, multiple stations can be sent on one channel transmission). ..COOL!!!

I once tried HD dish service (VOOM) which was cool while it lasted, but they went out of business. Bad weather had the same affect on dish reception as on antenna, bad weather = lower quality reception.

Anyway, I very much enjoy my free OTA DTV. Over the past 5 years, I have seen several stations come and go (such as an interesting version of MTV 5that only showed '80 videos, and an interesting cartoons-only station). The public television stations in my area were the first to get digital HD equipment, so their nature shows were my first HD "wow" stations to show friends how great true HD can be.

[Robert Grant]

No amount of signal strength will help you with this problem, but an outdoor antenna will likely help for another reason.

When you use an indoor antenna for DTV, there will always be some degree of multipath reception, as signals are reflected by other houses, buildings, mountains (if you are near any) and trees (in analog reception, mild multipath produces the classic "ghosting" problem. One may recall a windy day when on UHF reception one could not get the picture to stop rolling.)

The very first ATSC (DTV) receivers required a signal that was free of multipath, and could only be used with an indoor antenna if a signal had an unobstructed path to the antenna (e.g, in a window on the side of the building facing a transmitter, with no nearby buildings in the direction of the station).

Newer DTV tuners (including, I believe, all CECBs) can adujst to multipath by assessing the multipath effects on a signal, and "subtracting" the reflections from the total to arrive at a usable bitstream.

The problem with windy weather (and, BTW, it is not the rain, nor the snow, and, with good UHF signals, not lightning) is that when nearby tree branches are windblown, the multipath reflections from trees are changing with time, and the tuner can't "keep up" with the changing multipath condition.

An outdoor antenna aimed at a station has far less multipath to deal with in the first place, and the multipath effects through the tree branches are often not strong enough to corrupt the signal.

Incidentally, not all DTV is UHF. UHF has a much larger share of the total DTV station "stock" than analog, but many stations are and will be on VHF-High band (7-13), with the majority of current analog VHF-High stations going to their true original channels for DTV after June 12th.

[JimJ[VT]]

s has also been mentioned in other posts, radio is not the best medium for emergency information (the Emergency Alert System notwithstanding), as weather radar cannot be seen in radio weather reports.

At least around here, whenever there's pretty significant weather, the SKYWARN net on 2 meters is what to be listening to. Yeah, there are no pretty graphics, but that's where the TV stations are getting their on-the-ground reports from anyway.

[Jeffhs]

Originally Posted by JimJ[VT]

At least around here, whenever there's pretty significant weather, the SKYWARN net on 2 meters is what to be listening to. Yeah, there are no pretty graphics, but that's where the TV stations are getting their on-the-ground reports from anyway.

I was referring to how ordinary people get severe weather information. Most people outside amateur radio do not know what SKYWARN is or where to hear the information from the network. Moreover, Doppler radar (or just plain radar, for that matter) is beyond the understanding of most nontechnical people as well. One of the television stations in Cleveland (the NBC affiliate on channel 3) calls its weather radar "X-Band Doppler", "Nexrad Doppler" and one other term that escapes me as I write this. These terms mean nothing to most people watching TV weather forecasts. I have often wondered why that station doesn't just do the weather forecast without all the fancy terminology to identify the radar gear, which, again, most people watching these forecasts could not care less about. I am an amateur radio operator and do in fact know a few things about the SKYWARN system, but when I watch the weather on TV all I want to know is the temperature and whether or not it is going to rain or snow outside my window, not the nuts and bolts of weather forecasting. The same TV station that bamboozles viewers with its "X-Band Doppler" weather radar has a meteorologist (where did that word ever come from, for crying out loud?--weather forecasting has nothing whatsoever to do with meteors) who used to work for CNN in Atlanta. The man, who does the television station's noon weather reports during the week, does a creditable job delivering the weather forecast, but, IMHO, he tells his viewers much more than they need to know about weather. For example, he almost always identifies the type of clouds that will accompany the weather for any given day: cirrus, cumulus and whatever. For crying out loud (again), I don't know a cirrus cloud from a hole in the ground. This is also the reason I do not watch the news on Cleveland's FOX television station; they have a meteorologist (there's that word again) who has been with the station for perhaps fifty years, who does his forecasts the same as the other man on channel 3. I can't help wondering if the guy on channel 3 is taking lessons from the other one on channel eight, the FOX affiliate. Hmmm.

[NowhereMan 1966]

Originally Posted by Jeffhs

I was referring to how ordinary people get severe weather information. Most people outside amateur radio do not know what SKYWARN is or where to hear the information from the network. Moreover, Doppler radar (or just plain radar, for that matter) is beyond the understanding of most nontechnical people as well. One of the television stations in Cleveland (the NBC affiliate on channel 3) calls its weather radar "X-Band Doppler", "Nexrad Doppler" and one other term that escapes me as I write this. These terms mean nothing to most people watching TV weather forecasts. I have often wondered why that station doesn't just do the weather forecast without all the fancy terminology to identify the radar gear, which, again, most people watching these forecasts could not care less about. I am an amateur radio operator and do in fact know a few things about the SKYWARN system, but when I watch the weather on TV all I want to know is the temperature and whether or not it is going to rain or snow outside my window, not the nuts and bolts of weather forecasting. The same TV station that bamboozles viewers with its "X-Band Doppler" weather radar has a meteorologist (where did that word ever come from, for crying out loud?--weather forecasting has nothing whatsoever to do with meteors) who used to work for CNN in Atlanta. The man, who does the television station's noon weather reports during the week, does a creditable job delivering the weather forecast, but, IMHO, he tells his viewers much more than they need to know about weather. For example, he almost always identifies the type of clouds that will accompany the weather for any given day: cirrus, cumulus and whatever. For crying out loud (again), I don't know a cirrus cloud from a hole in the ground. This is also the reason I do not watch the news on Cleveland's FOX television station; they have a meteorologist (there's that word again) who has been with the station for perhaps fifty years, who does his forecasts the same as the other man on channel 3. I can't help wondering if the guy on channel 3 is taking lessons from the other one on channel eight, the FOX affiliate. Hmmm.

I wonder that myself, where the word "meteorologist" came from. I asked that question in my mind today as I was driving around in my truck on deliveries. Myself, I like to know the basics first and then go through the details in case if I'm in a rush or something.

[AUdubon5425]

Thanks for that Robert, I was not aware of the multipath issues.