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post #4771 of 4785 Old 12-30-2016, 09:18 AM
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Originally Posted by ProjectSHO89 View Post
WIAT utilizes an ultra-high gain transmitting that is also directional, aimed due north. In addition to only sending 184 kW of its million watts in your direction, its vertical beam-width is very narrow which means the bulk of that power is well up in the air above the mountain you're behind.
Interesting. So these big orange antennas at the top of the towers on Red Mountain are all pointed in a single direction? My expectation was they were omnidirectional. How do they decide what direction gets their signal? From an advertiser's standpoint, they are pointed at the most rural population areas. The bulk of the advertiser's target demographic are south of the towers, definitely not North. A puzzler.

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post #4772 of 4785 Old 12-30-2016, 09:23 AM
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Originally Posted by rabbit73 View Post
Where can I go to get this image?

The "direct signal path" line appears to indicate that I may have better luck aiming the antenna not only in the direction of the tower but also inclined upwards to follow the slope of the terrain between me and the mountain that's obstructing the LOS.

I never see antennas "tilted back", they always appear to be tilted straight ahead in whatever direction they are aimed. Would it be better to aim the face of the antenna so that it is perpendicular to the signal path line?

Or, it the signal path line only theoretical and the actual signal paths are quite different?

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Last edited by vestaviascott; 12-30-2016 at 09:41 AM.
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post #4773 of 4785 Old 12-30-2016, 10:56 AM
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Where can I go to get this image?
I created that image, and the contour map just after it, for you using the software at this site:
http://www.heywhatsthat.com/profiler.html

There isn't much in the way of instructions on using the terrain profile software, so I had to figure it out for myself. I can walk you through an example if you desire.
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The "direct signal path" line appears to indicate that I may have better luck aiming the antenna not only in the direction of the tower but also inclined upwards to follow the slope of the terrain between me and the mountain that's obstructing the LOS.
It often helps; you just have to try it. A few antennas have a built-in tilt feature; most do not which requires a custom mod.
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Or, it the signal path line only theoretical and the actual signal paths are quite different?
Yes, the red signal line is only theoretical; it obviously can't go through the mountain. As ProjectSHO89 and I have been trying to tell you, the mountain and the ground clutter on it are causing diffraction of the signal which creates a non-uniform wavefront with hot spots and cold spots. This means that the best location for the antenna might not be where you want to put it.

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Last edited by rabbit73; 12-30-2016 at 11:14 AM.
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post #4774 of 4785 Old 12-30-2016, 04:07 PM
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Yes, the red signal line is only theoretical; it obviously can't go through the mountain. As ProjectSHO89 and I have been trying to tell you
Understood. The signal can't go through the mountain. I don't think I ever indicated that I thought it could, but if I have to say it, I understand the signal can't go through the mountain.

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post #4775 of 4785 Old 12-30-2016, 07:32 PM
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So these big orange antennas at the top of the towers on Red Mountain are all pointed in a single direction? My expectation was they were omnidirectional.
No and not necessarily. You'd have to look at the license data for each of them to see what they use.

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How do they decide what direction gets their signal?
The FCC. Stations are licensed for specific geographic areas (with an interference-protected "contour"). It is often necessary to control how far the signals go in certain directions on specific channels so as to protect the contours of stations in adjacent markets. It's like a big 3-D jigsaw puzzle. The advertisers do not get a voice in the licensing decision.
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post #4776 of 4785 Old 12-30-2016, 08:12 PM
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Originally Posted by ProjectSHO89 View Post
No and not necessarily. You'd have to look at the license data for each of them to see what they use.
Thanks. If that is available online, do you have a link that I can use to research it myself?

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Stations are licensed for specific geographic areas (with an interference-protected "contour").
In that case, since I'm able to get NBC 13 virtually without trying, I'm guessing if I were able to access the same data you are looking at, I'd find that the NBC spectrum is mostly coming in my direction and as you've already indicated, the CBS Wiat 42.1 signal is almost opposite my direction.

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post #4777 of 4785 Old 12-30-2016, 08:15 PM
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I ever indicated that I thought it could, but if I have to say it, I understand the signal can't go through the mountain.
Sorry, no offense meant. It was not my intention to insult you. I should have added the green line in the first image.
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post #4779 of 4785 Old 12-30-2016, 10:02 PM
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Thanks @rabbit73 and @ProjectSHO89 for all the helpful info. I really appreciate it.

Taking your advice I did a few things today that have helped me get 42.1 CBS finally.

1) I downloaded a signal quality App for my iphone (Signal CH $3) that works with my HDHomeRun & allows me to dial in a channel and see a live signal meter (quality and strength) on my iphone that updates live as I move the antenna.

2) I drove to home depot and purchased a 10 foot stiff PVC pipe for $5. I mounted the antenna to the top of the PVC pipe and slid it down into the mast mount of my Directv satellite dish mount (near perfect fit)

The combination of these two things, along with your advice has allowed me to get a signal from all 4 majors, including the really hard one, CBS 42.1

Now that I know this will work, I'll be replacing the PCV pipe with a galvanized steel pipe for increased rigidity and stability. The AntennaCraft HDX1000 antenna is light but just heavy enough to bend the PVC slightly.

Thanks.

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Last edited by vestaviascott; 12-30-2016 at 10:05 PM.
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post #4780 of 4785 Old 12-31-2016, 04:45 AM
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Thanks. If that is available online, do you have a link that I can use to research it myself?
Sure. It's all in the public record at the FCC's website. https://www.fcc.gov/media/television...k-menu-block-4

www.rabbitears.info has the same data (pulls from the FCC database) in an easier to use interface with a lot of extra options. You may find it invaluable.

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In that case, since I'm able to get NBC 13 virtually without trying,
WVTM operates on VHF 13. VHF signals bend (diffract) over terrain than do UHF signals. Additionally, their tower is in a different location and your signal path from that tower to your antenna happens to be adequate.

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The combination of these two things, along with your advice has allowed me to get a signal from all 4 majors, including the really hard one, CBS 42.1
Cool! Happy to be part of the solution.

Good luck, make sure that extension is well stabilized against wind stresses.

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The AntennaCraft HDX1000 antenna is light but just heavy enough to bend the PVC slightly.
Hmm, somewhere along the line you appear to have changed antennas. This started out with a CM 8 bay, as I recall.
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post #4781 of 4785 Old 12-31-2016, 08:47 AM
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Originally Posted by ProjectSHO89 View Post
Hmm, somewhere along the line you appear to have changed antennas. This started out with a CM 8 bay, as I recall.
The CM 8 bay is an antenna I've had for several years. I've used it solely as an attic antenna in the past. The wife and neighbors don't care too much for the looks of it, so I've only been using it for field tests.

A couple weeks ago when I decided to "cut the cord" and cancel my Directv satellite service, I ordered the AntennaCraft in an attempt to get the same performance as the CM 8 bay in a smaller, more "wife friendly" looking package, and it has built in amplification. It basically looks like the satellite dish it's replacing so it meets the WAF.

The AntennaCraft just arrived a couple days ago and I've been using it since. It's so much easier to handle up on the roof than the big CM and it appears to be as powerful, less directional, and wrapped in an eye pleasing package that looks like a satellite dish. From what I've seen so far, I'm not sure why it's discontinued, but I'm glad I was able to score one.


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Last edited by vestaviascott; 12-31-2016 at 09:11 AM.
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post #4782 of 4785 Old 08-11-2017, 07:56 PM
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I have a CM4221 mounted outdoors with a CM7778 preamp.

Having a problem with 6-1(channel 50). My signal strength looks good (6/10 bars), but the picture keeps dropping out. My other channels dont seem to have this problem.

I would appreciate any suggestions on what to do.
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post #4783 of 4785 Old 09-01-2017, 03:10 PM
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I have a CM4221 mounted outdoors with a CM7778 preamp.

Having a problem with 6-1(channel 50). My signal strength looks good (6/10 bars), but the picture keeps dropping out. My other channels dont seem to have this problem.

I would appreciate any suggestions on what to do.
6-1 (Digital Channel 50) is Fox 6. I get some signal drop out but mostly solid locks on that channel from my location, which is just on the other side of Shades Mountain from the towers (appx 3 miles away). Where are you located?

Here's a shot from behind my antenna. When its windy, those trees that are at the top of the shot - and especially the tall one midway, cause signal path disturbance which makes my signal fluctuate somewhat. That tall tree is directly between my antenna and the towers, however, this location is the sweetest spot I've found to locate the antenna for all the major channels I want to receive.



From this shot, the towers are directly over the house in the foreground. Angling my antenna so that its titled back slightly appears to give me the best reception of all Red Mountain tower signals (Fox 6, CBS 42, NBC 13). The ABC affiliate, ABC 33/40 tower is located in Windham Springs, which is about 10-15 degrees left of the Red Mountain towers (from my location). I aim my antenna in the direction of the Red Mountain towers. The ABC 33/40 signal comes in about the same as the CBS 42 signal (they are my weakest, most unreliable channels that hover around 50-55% signal quality most of the time. Just enough to be annoying at times.


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Last edited by vestaviascott; 09-01-2017 at 03:19 PM.
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post #4784 of 4785 Old 09-01-2017, 03:44 PM
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Originally Posted by vestaviascott View Post
6-1 (Digital Channel 50) is Fox 6. I get some signal drop out but mostly solid locks on that channel from my location, which is just on the other side of Shades Mountain from the towers (appx 3 miles away). Where are you located?

Here's a shot from behind my antenna. When its windy, those trees that are at the top of the shot - and especially the tall one midway, cause signal path disturbance which makes my signal fluctuate somewhat. That tall tree is directly between my antenna and the towers, however, this location is the sweetest spot I've found to locate the antenna for all the major channels I want to receive.



From this shot, the towers are directly over the house in the foreground. Angling my antenna so that its titled back slightly appears to give me the best reception of all Red Mountain tower signals (Fox 6, CBS 42, NBC 13). The ABC affiliate, ABC 33/40 tower is located in Windham Springs, which is about 10-15 degrees left of the Red Mountain towers (from my location). I aim my antenna in the direction of the Red Mountain towers. The ABC 33/40 signal comes in about the same as the CBS 42 signal (they are my weakest, most unreliable channels that hover around 50-55% signal quality most of the time. Just enough to be annoying at times.

Here is an overhead shot with direction lines to the Red Mountain towers. The large building with parking lots at the top left represents the tallest elevation of the mountain I'm on.


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post #4785 of 4785 Old 09-01-2017, 03:53 PM
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Here are my signal quality/strength numbers from the "Signal GH" iphone app that's reading from my HD HomeRun device:

Channel | Signal Quality | Signal Strength

Fox 6 (Digital 50) | 68% | 73%

NBC 13 (VHF Digital 13) | 72% | 87%

CBS 42 (Digital 30) | 64% | 70%

ABC 33/40 (Digital 36) | 60% | 74%

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