TV Antenna Issues

Flyinfool

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OK it always seems that there is some one that will know something or at least have some good ideas.

Here is my situation. The cable price just took a dramatic price jump and has exceeded my wallet tolerance.
So I got an omnidirectional antenna since I am only about 15 miles from the transmitters.
Overall the antenna works great.

The problem is, the transmitters are all almost due north of me. Directly across the street to the north is a 5 story high brick apartment building. The picture quality is still flawless. Now the fun part. I live very close to an international airport with a lot of airliner traffic. The airliners go by about 2 city blocks to the south of me and are at less than 1000 feet AGL on final for the favorite runway. The planes go by about every 2 - 3 minutes. With each plane that goes by It wipes out my TV picture and sound due to loss of signal. I think that what is happening is that the broadcast signal is bouncing off the side of the airplanes and hitting my antenna out of phase with the broadcast signal so neither one can get through.

I bought and tried a directional antenna and that helped a little. I get the signal interruption for a short time and then it clears when the plane is exactly off the back of the antenna and then goes out again as the plane continues on by.

Would it help to put up a wall of aluminum foil on the back side of the antenna to try to block the reflected signal? DO I need to ground it?
Would I be better off spending the big bucks on a bigger more directional antenna?

Any other ideas form those that understand how radio waves work????
 
Are all your channels coming from the front? If so a metal mesh can help attenuate the unwanted signal. You can not place the mesh too close to the elements though. The problem is Omni is a 360 degree design. What you likely need is a more directional antenna. If you look at Channel Master 4 bay or 8 bay units, there is a reflector behind the elements. It sort of blocks the back from spurious signals and boosts the signals coming to the front.

This site should help, lots of info in the different areas.
 
Good ole multi-path...

May not be the issue but try this...

If you are close to transmitters then the field strength should be high and if true multipath then it could be way high.

So look for a good yagi version, more directional the better.

With portable tv or helper swing for good spot but look OPPOSITE direction.

If the direct signal is being wiped out by reflected path then maybe a reflected path may be less an issue.

You may find a path that the different signals do not like up as well so the null is not as bad.

Also try rotating antenna 90 degrees as that polarity may have better outcome.






Sent from my SAMSUNG-SM-G930A using Tapatalk
 
What kind of directional antenna did you get? I use the 2 bay version of the Channel Master above with good results and it wasn't too expensive.

With only 15 miles to the transmitters, try aiming to the side a little. The gain from the antenna should still allow a good signal, particularly if it is outdoors, but might prevent a reflection from interfering. If there is a building to the side, a reflection from it might be strong enough with the directional antenna to get a good signal but block the other reflections or at least change the timing enough to help.

Different tuners can also make a difference. Some are less susceptible to some types of interference.

Avoid "active" or amplified antennas. At this range, amplifiers are more likely to hurt than help.
 
My wife noticed that every time that she stood at a certain place by the radio listening to her favorite fm station it would fade. This is the radar principle at work. So either move the radio or her. In your case try rotating the antenna and see what happens. If that still does not work, you can always go down in your shop and play with your lathe.
 
Is this happening on all the OTA channels? I though I had it bad with a tree covered hill in my line of sight with the towers. The building, with all its plumbing and wiring would really attenuate the signals, not to mention having all kinds of multiple signal paths. Antenna radiation patterns are displayed on polar coordinate graphs were the further the point is from the the center, the higher the gain. https://www.electronics-notes.com/a...on/installation/alignment-pointing-aiming.php

As pdentrem stated, and omnidirectional antenna receives equally well in all directions so the graph is a circle centered on the center point. directional antennas increase gain in one direction at the expense of all other directions resulting in lobes. What is desired is an antenna with a single forward facing lobe and no lobes in any other direction. Typically, there is a small lobe to the rear. What is usually specified for a directional antenna is a front to back ratio expressed in decibels.

Because of the attenuation of the building to your north, you need an antenna with a very high front to back ratio to minimize the effect from the planes. With UHF antennas, this is easier because of their compact size. Stacked array UHF antennas seem to have fairly broad forward lobes. Yagi and log periodic antennas (they're tho ones that look like fish skeletons) tend to be better focused. Because of your proximity to the transmitting towers, you may also benefit from an attenuator. It will decrease the strength of your primary signal but it may also knock the strength of the interfering signals.

I use a highly directional Yagi antenna (https://manuals.solidsignal.com/HD8200U_Specs.pdf) and usually have to rotate my antenna slightly in the Spring and Fall to account for the difference between leaves and no leaves. It has a front to back ratio of around 20:1 and fairly narrow lobes except for the one or two lowest channels.
 
Due to my location my antenna works fixed (no rotator) I have my antenna pointed to Toronto with the back facing towards Colden NY where the major network towers are sited. I therefore receive all the networks that are OTA. The antenna I use would not work in your case. I do have my old Yagi unit that is about 4 feet long, but then I would need a rotator.

This my build from another user’s plans. Very simple and quite effective!
Pierre

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