TV signal dilemma

[jrgagne99]

Originally Posted by rickbb

Correct, the transmitter is on the left and your location is on the right.

I think the deep chasm at the right is an artifact of the plot, i.e. not real. The feature seems to appear in a number of different terrain profile plots (mine included) where there is clearly no cliff-face.

[Tower Guy]

Originally Posted by rickbb

The closer CBS has a worse NM -1.2 which will make it harder to get than the further one. My bad on the NBC, it is close, but still a low NM and Kw at the antenna will make it hard to get.

Actually, 30.2 KW on channel 6 is high power for low VHF. Yet TVfool does not subtract the 4 db extra low band noise that is added into the FCC coverage of low band. Even then, none of the antennas suggested are designed for low band.

The difference in noise and the higher gain of UHF antennas will make reception of WFSB easier than WRGB.

[rabbit73]

I don't have your exact location coordinates by PM, but I think the 2Edge designation for WVIT is correct; there is terrain interference.

[jrgagne99]

Originally Posted by rabbit73

I don't have your exact location coordinates by PM, but I think the 2Edge designation for WVIT is correct; there is terrain interference.

I agree there is interference, but it is not as bad as the TVfool terrain plot suggests. The terrain plot makes it look like the antenna is at the bottom of Clayton Ravine.

[mjcarpino]

rabbit73, thanks for those images. They are showing exactly what my problem is. In the 3rd image (google) you can see where the signal is stronger prior to the last peak before the antenna. I'm curious how you obtained the 1st image showing the elevations, etc.

[rabbit73]

rabbit73, thanks for those images. They are showing exactly what my problem is. In the 3rd image (google) you can see where the signal is stronger prior to the last peak before the antenna.

I'm glad that you found it helpful and have confirmed that the hill exists.

I'm curious how you obtained the 1st image showing the elevations, etc.

The tvfool terrain profile gave me a clue that there might be a problem, so I used a different software for the terrain profile found here:
http://www.heywhatsthat.com/profiler.html

To use the software, I had to enter your coordinates and the coordinates of the transmitter. Since I don't know the coordinates of your antenna, I had to make an estimate derived from your tvfool report. So, there could be some errors from that, along with some inherent in the software.

It takes a while to learn how to use it, because there isn't much in the way of directions.

jrgagne99 has some doubts about the accuracy of the software. In his case, it shows a hill in the signal path that he says isn't there. I think what happened in his case, there is a tall stand of trees in the signal path that was read as an increase in elevation. The elevation readings were probably done by aerial survey, which might include the height of the trees. Years ago, elevation was measured on the ground from benchmarks. In the final analysis, it's just as damaging to the signal as a hill.

I think this is what he remembers:





This is his thread:
http://forum.tvfool.com/showthread.php?t=16101

This view supports JR's contention that there isn't much of a nearby hill in the WCAX signal path, but there are certainly a lot of trees, unless they have been clear cut.

[OTAFAN]

With the repack coming soon, the Yagi
will be at an even greater disadvantage......UHF TV will end at
Rf 36.... JoeAZ: Would you please post a link to your above comment? I've been reading up on the FCC repack this holiday as to how it might effect OTA reception, and did not see anything about UHF frequencies ending at Rf36, only around Rf51. Not doubting you, but just would like to hear it from the FCC horses mouth.

At least we have another 36 plus months (maybe more) before it finally settles down, hopefully. I know the FCC did say they did not want OTA viewers to have to scan their TVs more than twice to update broadcasters changes, or once for viewers to adjust their directional antennas rooftop or indoors. How kind of them!

But I guess this all came about to give more spectrum for cell phones. T Mobile got the lions share at auction with around 8 billion bid! I should have realized when watching Star Trek back in the 1960s, that the crews communicators would be all the rage in the 21st century! Geez.....

[rabbit73]

Before the Incentive Auction ("repack") UHF was 14-51; after it will be 14-36. Before the auction, it wasn't clear how many channels would be left for TV broadcasting. One of the purposes of the auction was to determine how many channels would be left.

http://www.tvtechnology.com/resource...-abound/280362

Trip in Va started a repack thread on the AVS Forum:

http://www.avsforum.com/forum/25-hdt...um-repack.html

Trip runs the rabbitears.info site and works for the FCC, so he would qualify as the FCC horses mouth.

He also started a repack thread on the Canadian forum:
http://www.digitalhome.ca/forum/81-o...epack-ota.html

You can see the Repack Plan here; it takes a long time to download:
https://www.rabbitears.info/repackchannels.php



If you look up WVIT using that tool, you will see WVIT moving from 35 to 31:



You can also look it up here:

http://www.rabbitears.info/market.ph...&callsign=wvit

where you will see 35 > 31 by the WVIT callsign.

[OTAFAN]

Thanks for the quick reply and links rabbit73!

So.....what's your best guess regarding using our current antennas since UHF Rf is going to stop at 36? Will we need to something different for optimal reception???

[rabbit73]

Will we need to something different for optimal reception???

We will need antennas rescaled for 14-36 for optimal reception, but I doubt we will see many made for the consumer market. Antenna manufacturers are not going to rescale and build antennas for the 14-36 UHF band unless they can make a profit doing it.

When the UHF band was cut to 14-51, very few manufacturers rescaled their antennas.

Regarding the comment by JoeAZ, yagis have a gain vs freq curve that slopes up, so they will have poor performance at the low end of UHF.

Anennas Direct didn't rescale the 91XG, but they did rescale their bowtie antennas for 14-51.

[OTAFAN]

Well, I'm sure you're going to be even more busy helping people solve their OTA reception issues over the next ten years, rabbit73--so don't plan on going anywhere; we need you now more than ever!

There's a lot to think about here and much more reading that I need to do to keep my TV viewing optimal in the next few years. I'm probably going to loose some sleep over this.....

Thanks again as always!

[mjcarpino]

Well the results are in.....time to search for other cord cutting solutions.

I tested both Steller Labs 30-2430 and 30-2370 raised 10' above roof top, with and without a pre-amp. Essentially no discernible difference in all my readings using the Tivo signal strength function.

WTNH (ABC) chan 8.1 was the only one where I was able to have a picture, although mostly pixelated. The other 2 UHF channel I was shooting for (WRGB and WVIT) showed a signal, but not enough for a picture.

[jrgagne99]

WTNH (Real-10) would not be expected to come in on either the 2430 or the 2370. Neither would WRGB (Real-6). Only UHF (channels 14 and up). Regarding WVIT and WFSB (and maybe even WTIC), did you try "walking the roof" to find a sweetspot? In my deep fringe area, i see 10 dB or more variation over only a few feet in X, Y, and Z (sometimes even inches).

[mjcarpino]

Yes...walked the roof as well as on the ground. Couldn't see much difference in all locations tried and definitely never pulled in a picture except ABC as noted previously.

I want to thank everyone for the information and help in my attempt to receive OTA TV at our new home. But for now I'm giving up....antenna are being returned.