Choppy signal from 2 miles

donny44131 · 4-May-2012, 1:57 AM

I have decided to cut the chord and cancel DirectTv and go with DTV. I installed an outdoor RCA ANT751R and mounted it to the existing satellite mount. Now this location does happen to be slightly below the ridge line of the roof. I connected the existing RG6 cable and pointed it in the right direction using my compass. The line does get split to three TVs so the runs can get a little long but there is already an amplifier connected up at the splitter the the DirectTv guy installed. There is a grouping of about 6 main channels about 2 miles away. 4 of them come in great. 2 of them are really choppy. There are no major obstacles I between me and the towers. I have added the link to my report below. Please help, this is driving me nuts.

http://www.tvfool.com/?option=com_wr...de65d1a9d2c027

Electron · 4-May-2012, 2:22 AM

What direction is the antenna aimed??
Here is how to aim antennas , http://www.kyes.com/antenna/pointing/pointing.html.
Identify the channels that are choppy by call sign and affiliation. Example: WKYC-DT Real channel 17 , Virtual channel 3.1 NBC

donny44131 · 4-May-2012, 2:34 AM

The antenna is pointed in the correct direction toward the tower that I get bad reception from.

GroundUrMast · 4-May-2012, 5:48 AM

Have you tried pointing the antenna at about 145°?

Also, the signals are extremely powerful because you are so close to the local transmitter towers. You need to completely remove the amplifier from the system. I'd expect any amplifier to overload which will make reception more difficult. You have so much signal power, you may actually need an attenuator.

donny44131 · 4-May-2012, 11:29 AM

I have tried removing the amplifier for a short time with no real change in result. How can I test my signal to see if I do need to reduce the strength? Is it possible that I am too close?

Also, when you say point the antenna at 145 degrees you are basically suggesting pointing it in the opposite direction, thinking the signal may in fact be to strong?

GroundUrMast · 4-May-2012, 2:16 PM

Yes, I think there is far too much signal power. Each of the top four stations are radiating between 500,000 and 1,000,000 watts ERP and you are only 2 miles away. A test meter is not needed, look at the Signal Pwr (dBm) column and you'll see the values highlighted in red, a warning of tuner overload in many cases... with out any amplifier involved. (In most cases, I'd be curious to know the make and model of the amplifier... not in this case though. Any amplifier is going to make the situation worse.)

When you look at the NM (dB) column of your report, you see values in the +70 and +80 range. That suggests enough power to drive almost 1000' of RG-6 with no amplifier.

I'll bet one or more of your TV's will receive several stations with the coax completely disconnected from the tuner.

An online search for "Holland FAM-10" should give you a list of sources for attenuators. I would expect you'll need no less than 10 dB... possibly as much as 40 dB.

Yes, I would try aiming away from the strongest signals, favoring the weaker signals. The ANT-751 is like most Yagi and LPDA antennas, more sensitive in one direction, but able to receive from the backside at somewhat lower sensitivity.

donny44131 · 4-May-2012, 4:41 PM

Thanks for the advice, I will try pointing the antenna in the opposite direction and post an update later tonight hopefully.

Electron · 4-May-2012, 5:21 PM

http://www.antennasdirect.com , has a variable attenuator to 'dial down' signal strength.

donny44131 · 5-May-2012, 3:29 AM

I removed the amplifier and directed the antenna away from the towers. It helped a little bit but I think I will still need that attenuator. I'll come back with some answers once I have that installed. Thanks again.

No static at all · 5-May-2012, 3:40 PM

You also have a searing amount of FM energy in your area. I suggest ordering an HLSJ as well when ordering the attenuator. Many recommend using a terminator on the unused LO output of the HLSJ, but I have personally never seen it make a difference either way.

All 3 items can likely be ordered from the same vendor to save on shipping costs.

Good luck!!

donny44131 · 13-Jul-2013, 1:54 AM

I realize its been over a year but I thought it would be polite to follow up. Today was the day I finally made the switch to digital antenna.

I pointed by antenna at about 200 degrees and placed a 20 dB attenuator pad in line that I got from smarthome.com (they sell a mixed pack). After doing that, I have just about every channel in the area.

So you guys were right, my signal was too high.

Thanks for the help!