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KNVA Power?
- Thread starter jras20
- Start date
Both stations are 5,000 kw ERP, from the same tower, apparently diplexed from the same antenna. Transmitters are identical, IIRC.
Both put in equally good signals at relatives' house in Austin.
Both put in equally good signals at relatives' house in Austin.
I meant to add that by "both stations" I mean KXAN and KNVA.
I've never bought in to the idea that low-end UHF's do better than high-end channels. At my location in Houston, I'm 25 miles from the Missouri City antenna farm. Channels 57, 61, and 67 come in just as well as 14, 20, and 26. And during good tropo conditions, I've seen channel 60 in the Rio Grande Valley (300 miles away) come in just as well as channel 23 there. And this is on decades-old portable sets with hoop antennas.Greg Branch said:KNVA is the highest frequency channel that you are trying to receive. Oftentimes, physics makes the higher UHF channels harder to receive than the lower.
This isn't the AM band we're talking about, where there is a large difference in propagation characteristics between the top and bottom of the dial. If a difference exists on the UHF TV band, it is negligible--you need to have a bigger change in frequency/wavelength to really start to notice some changes.
I would think that a UHF antenna, particularly a small one, would work better on the higher channels, as it is more efficient for the shorter wavelengths.Also, some antennas have a gain dropoff at the higher UHF frequencies.
What I am getting at is not that the higher frequency channels propagate any less farther than the low end channels. However, the higher you go in frequency, the more "line of sight" your signal becomes. Higher end UHF channels are more likely to suffer signal loss from trees, hills, buildings, etc. Also, the higher frequency means a smaller beamwidth. So, you must be more precise in aiming your antenna. Remember, the current UHF TV band extends from 470 MHz to 806 MHz. That's a quarter-wavelength difference of 6" versus 3.5". Antenna manufactures have to make a compromise on how to cut their bay or dipole, and often they "bias" the antenna toward the lower end of the band, because that is where most of the higher rated channels are at.
Tropo is not line of sight, so when those conditions exist, typical ground based obstacles do not affect the signal.
I have a Channel Master 4228 8-bay that works very well on UHF channels below about 50. Starting at channel 50, the gain rolls off quite significantly, making the 4228's performance worse than that a small yagi.
The good news is that, with the upcoming death of analog TV, all of those channels above 50 are going away, so we won't have to bother with them anymore.
Tropo is not line of sight, so when those conditions exist, typical ground based obstacles do not affect the signal.
I have a Channel Master 4228 8-bay that works very well on UHF channels below about 50. Starting at channel 50, the gain rolls off quite significantly, making the 4228's performance worse than that a small yagi.
The good news is that, with the upcoming death of analog TV, all of those channels above 50 are going away, so we won't have to bother with them anymore.
jras20 said:I'm going to hate that day when analog tv goes off the air, more than likely I probably wont even buy a box unless it is just dirt cheap.
Our local Wal-MArt was selling ATSC tuner boxes for $79.95 the other day. Sure it was a blow out, but I'll bet they aren't losing a dime. They will be dirt cheap.
In fact, it's worth it to buy one right now. There is lots of digital TV to watch over the air. The picture improvement is remarkable even on a plain old NTSC set.
Chuck said:Our local Wal-MArt was selling ATSC tuner boxes for $79.95 the other day. Sure it was a blow out, but I'll bet they aren't losing a dime. They will be dirt cheap.
In fact, it's worth it to buy one right now. There is lots of digital TV to watch over the air. The picture improvement is remarkable even on a plain old NTSC set.
Agreed. Even if one does not want to invest in HD at this point, SD digital TV at 480i can provide DVD quality picture and sound, plus the extra sub-channels like weather radars and The Tube.
Eventually, all new TV's will have built-in ATSC tuners, so you when you buy a new TV you won't have to bother with a box to watch terrestrial TV.
Greg Branch said:Chuck said:Our local Wal-MArt was selling ATSC tuner boxes for $79.95 the other day. Sure it was a blow out, but I'll bet they aren't losing a dime. They will be dirt cheap.
In fact, it's worth it to buy one right now. There is lots of digital TV to watch over the air. The picture improvement is remarkable even on a plain old NTSC set.
Agreed. Even if one does not want to invest in HD at this point, SD digital TV at 480i can provide DVD quality picture and sound, plus the extra sub-channels like weather radars and The Tube.
Eventually, all new TV's will have built-in ATSC tuners, so you when you buy a new TV you won't have to bother with a box to watch terrestrial TV.
How does HD work in the fringe? I got a place that I would love to try it out, I just wonder how well it will pull in, I can get analog channel 4, 5, 12 out of San antonio, not very clear, but clear enough to watch it. How much better will it work in the fringe?
jras20 said:How does HD work in the fringe? I got a place that I would love to try it out, I just wonder how well it will pull in, I can get analog channel 4, 5, 12 out of San antonio, not very clear, but clear enough to watch it. How much better will it work in the fringe?
It's hard to answer your question. There are too many variables - transmitter power, antenna height, obstructions between you and the transmitters, what kind of antenna and STB you have.
Suggest you go to http://www.antennaweb.org and play around with the antenna finder application. Type in your physical address, and it will give you a good idea of what you can get, both analog and digital, at you location, direction and what type of antenna you will need. It's not perfect, but it should give you a general idea of what you may be able to see.
Example - at my location, analog UHF from Shreveport at 50 miles is snowy because there is a hill and lots of trees between me and the transmitters. However, I can get the full power digital stations reliably 95% of the time. The lower power stations come in rarely and/or never.
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