Too close to towers - Omaha

[tekeeladude]

First time post, but have done a lot of reading/research before posting. I have learned a lot from this site over the last few weeks as I have ventured into the OTA world.

Issue: I live about 2-2.5 miles from three transmitter towers (ABC, CBS, NBC) and approximately 20 miles from another tower with Fox KPTM and CW KXVO. Without any antenna I can pick up ABC, CBS, and NBC. Same with an indoor antenna, but can sporadically get Fox and CW. To pick up the Fox and CW stations, I installed the Winegard Free Vision antenna where my DirecTV dish was mounted on the roof. Now I can receive Fox and CW, but ABC, CBS, and NBC sporadically drop out. The other PBS stations seems to come in just fine with no problems.

To help eliminate the overload from the close towers I put in place a 4-way splitter with 7db loss and that seemed to help. However when it has been raining the reception will still drop out on these close proximity stations. I even put in another 2-way splitter, but still am getting sporadic signal drop out. But I am able to get Fox and CW without any problems.

I also ran the FMFool report and found a close transmitter less than half a mile away. I picked up an FM trap for a few bucks from Radio Shack and installed that just in case, but haven't really noticed any change in reception.

I did place an order for an adjustable attenuator, but wanted to see if there was anything else I should try.

TVFool Report: http://www.tvfool.com/?option=com_wr...f1f0ef4622ef6d

Data from FMFool:
KIOS = 0.4 miles 55 kw Rx dbm = 3.1
KEZO = 2.2 miles 95 kw Rx dbm = -3.4

Antenna is facing approximately 185 degrees (neighbor's tree in direct line to Fox at 219 degrees). Trees immediately east and north of house. Trees across the street (South) approximately 150 feet away and 75 feet high.

Antenna connected to distribution point with RG6 quad. 3-way splitter at distribution point with home-runs to TVs. Only two TV's in use at this time, but plan on hooking up the third tv soon. Longest run is no more than 75 feet.

One last thing -- I did try an RCA ANT751 directional antenna pointed toward the Fox/CW tower, but that seemed to make things even worse. Seems like the gain was too high and caused constant drop out on ABC, CBS, and NBC.

Russ

[tekeeladude]

Some additional info.

Using Hauppauge 955Q USB tuner I was able to get some SNR info:

ABC: 0 - 31
CBS: 25-29
NBC: 27-31
Fox: 17-21
CW: 20-21

This is with the additional 4-way and 2-way splitters installed at the main TV.

[Tower Guy]

You could try placing the antenna on the side of the house facing FOX and CW.

[ADTech]

Your problem is most likely the trees.

[rabbit73]

Yes, trees can be a problem.

Without any antenna I can pick up ABC, CBS, and NBC.

It doesn't matter how much attenuation you use because the signal is getting into the TV after the attenuator. If you haven't grounded the coax, do that now with a grounding block.
http://www.digitalhome.ca/forum/show...&postcount=124
http://www.digitalhome.ca/forum/show...&postcount=126
http://www.digitalhome.ca/forum/show...&postcount=128
http://www.digitalhome.ca/forum/show...&postcount=137
http://www.digitalhome.ca/forum/show...&postcount=138

Then try more attenuation.

Next try two UVSJs in series to remove anything below UHF; use common and UHF ports.
Or, if you want 12, try two HLSJs in series instead of an FM filter; use common and high ports.
http://www.hollandelectronics.com/ca...-Diplexers.pdf

Last resorts:
1. Custom filters to attenuate your strongest signals.
http://www.tinlee.com/MATV-Bandstops.php?active=3
2. Screened enclosure for the TV
http://www.digitalhome.ca/forum/show...&postcount=136

And avoid the trees.
http://www.hdtvprimer.com/antennas/siting.html
scroll down to
Trees and UHF
sometimes the link doesn't work

I see a lot of trees in your area, Attachment No. 2.

[tekeeladude]

Thanks for all the advice. I thought the trees were a likely cause of the issues but was more concerned about the overload causing problems. I do have the coax grounded properly to the outside electrical connections.

Kinda odd this evening...lots of wind and some rain, but little to no pixelation or drop outs on the ABC station that was having the most problems.

[tekeeladude]

Update/Correction:

I stated above the trees were east and north of the house. Should have put west and north of the house. That puts the trees between the house and the close towers. These trees are 70+ year old oak trees and there is no option of eliminating them.

I had also mentioned the issue with receiving ABC, CBS and NBC with no antenna connected to the main TV. Turns out this is isolated to this TV only (older Visio). I placed another TV in the exact same position and connected to the same power outlet and was unable to receive any stations without an antenna.

The adjustable attenuator showed up today and I decided to test it with the connection at main TV. Using the Hauppauge tuner signal meter I was able to dial in the proper amount of attenuation to reduce the pixelation on ABC, CBS, and NBC while still being able to receive Fox and CW. I probably didn't have to use the Hauppauge, but it's nice to see a quantitative value when doing something like this. Btw, the PBS stations have not been an issue.

I really appreciate the knowledgeable information and advice. Going OTA has been a challenging, but very interesting project.

[rabbit73]

The adjustable attenuator showed up today and I decided to test it with the connection at main TV. Using the Hauppauge tuner signal meter I was able to dial in the proper amount of attenuation to reduce the pixelation on ABC, CBS, and NBC while still being able to receive Fox and CW.

Thanks for the report with the good news. Glad we were able to help you with an easy fix so that you didn't have to resort to extreme measures.

Being able to measure the improvement helps, as you can see by my signature.

What adjustable attenuator did you use?

[tekeeladude]

I am using the Antennas Direct ATT-1 Variable Attenuator.

[ADTech]

Interesting - I've actually never seen that work......

[tekeeladude]

Originally Posted by ADTech

Interesting - I've actually never seen that work......

I really think the problems I was experiencing are due to the tuner sensitivity in my main Visio TV. The other Visio TV doesn't seem to have the same issue using the same connection. I initially set the attenuator using the Hauppauge tuner and signal meter, but found that I could dial up the attenuation when using it with the main TV. So for in this particular instance, the adjustable attenuator works great.