Antenna TV. Interference even comes in the form of passing/accelerating cars.

W

WhatInThe

SF VIP
No cable or dish for TV so I'm using a couple of digital/hd antennas with an ampflier(still -can recieve lot). Digital tv extremely susceptible to interference. Like the old days and UHF channels in particular.

Took some time but I realized that accelerating cars, passing trucks can cause interference. My guess since acceleration is when the battery charges the most anything emitting a signal ie gps, wifi, phone etc transmits at it's peak. Throw in all the electronics in an engine or involved with a car there's alot of emf. Throw in a nearby railroad tracks/trains the power usage/emf. It worse as car accelerate over the rr tracks.
 

bowmore said:
The biggest noise comes from the spark plugs.
Click to expand...
I was thinking that but a lot of cars are only 4 cylinder cars with much smaller plugs than decades ago. It could affect signal infront of house but not a 1/4 mile down road?
 

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If you ever have a chance to buy into Fiber Optics, give it serious consideration. We have TV, phone and internet bundled on fiber, and it is the best service we've ever had.
 
If they are reachable WhatInThe, try turning the
aerials, if they are inside the house move them
to another location.

I sometimes get black screens on the TV when a
car passes, by moving it to the wall that is right
angles to where it is hanging cures this, it is a
combination of weather, parked cars and passing
traffic, with me.

Mike,
 
I get some interference that I have always attributed to vehicles with communication systems like FedEx, taxi cabs, etc...

I also get some interference depending on the weather conditions. I seem to get my best reception when it is cloudy and damp.

For now, I'll stick with the minor inconvenience of air TV and enjoy the money I save on some things that are more meaningful to me.

As I get older my world gets smaller and my priorities change so the idea of having some form of pay-TV may become more appealing to me.
 
WhatInThe said:
I was thinking that but a lot of cars are only 4 cylinder cars with much smaller plugs than decades ago. It could affect signal infront of house but not a 1/4 mile down road?
Click to expand...

Reminds me back in the 50s where every car and airplane went by, the picture would go crazy and noisy. Check Amazon for a noise reducer. Not sure if they have one but it should help.
 
Mike said:
If they are reachable WhatInThe, try turning the
aerials, if they are inside the house move them
to another location.

I sometimes get black screens on the TV when a
car passes, by moving it to the wall that is right
angles to where it is hanging cures this, it is a
combination of weather, parked cars and passing
traffic, with me.

Mike,
Click to expand...
It seems like you are using an indoor antenna. If you are getting a good signal, you can possibly use two antennas with a switch.
I remember we had to mount the antenna higher in order to minimize the interference.
The stronger the signal, the less interference.
It also depends on the antenna being used. A high gain antenna is more directional but it gives a better signal. I also remember rotors to move the antenna.
The technology for over the air television hasn't changed much from the old days except for UHF. All we had was VHF channels 2 to 13 .
 
I'm using 2 digital antennas now, a 30 mile and 40 mile with an amplifier on a catv splitter. Can get 2 sets of stations or about 30-40% of what's available there's 2 other sets of stations I can't get at all or must dedicate the antenna for them only. I take readings with a compass and use reference points so I can position them pretty quick but there are just too many times even in ideal position the interference in unbelievable.

I tried hdmi type cables,shorter and longer cables to no avail. I might splurge for a 50 mile plus or a different brand/shape antenna.
 
Pappy said:
Don. We’ve been looking at AT&T fiber service. Know anything about them?
Click to expand...

I don't know anything about AT&T service...our service is provided by our rural electric Co-Op...but Fiber, IMO, is far superior to any cable or satellite service we've ever had. Everything is crystal clear, and there are NO glitches, due to weather, electrical interference, etc., and the Bundle our Co-Op offers is cheaper than what we had been paying. After a couple of years on Fiber, I would highly recommend it.
 
WhatInThe said:
I'm using 2 digital antennas now, a 30 mile and 40 mile with an amplifier on a catv splitter. Can get 2 sets of stations or about 30-40% of what's available there's 2 other sets of stations I can't get at all or must dedicate the antenna for them only. I take readings with a compass and use reference points so I can position them pretty quick but there are just too many times even in ideal position the interference in unbelievable.

I tried hdmi type cables,shorter and longer cables to no avail. I might splurge for a 50 mile plus or a different brand/shape antenna.
Click to expand...
What are you using for coaxial cables to hook up the antenna to the television sets?
Good cables eliminate a lot of signal loss in transmission from the antenna to the set.
Check out what the homes close to you might be using.
 
Camper6 said:
It seems like you are using an indoor antenna. If you are getting a good signal, you can possibly use two antennas with a switch.
I remember we had to mount the antenna higher in order to minimize the interference.
The stronger the signal, the less interference.
It also depends on the antenna being used. A high gain antenna is more directional but it gives a better signal. I also remember rotors to move the antenna.
The technology for over the air television hasn't changed much from the old days except for UHF. All we had was VHF channels 2 to 13 .
Click to expand...
A high gain directional antenna should enable one to get away from this noise source.

I am not in favor of amplifiers on the antennas because they will amplify the noise right along with the desired signal. To make matters worse, many of them are easily overdriven resulting in all sorts of harmonic and intermodulation distortion byproducts. Usually these amplifiers are attached to omni-directional antennas so they unable to avoid unwanted noise. Amplified antennas is of those ideas that "sounds good", but in practice is a bad idea. The exception to this is if the amplifier is attached to the base of a high gain directional antenna where it can avoid picking up the noise source in the first place.
 
Pecos said:
A high gain directional antenna should enable one to get away from this noise source.

I am not in favor of amplifiers on the antennas because they will amplify the noise right along with the desired signal. To make matters worse, many of them are easily overdriven resulting in all sorts of harmonic and intermodulation distortion byproducts. Usually these amplifiers are attached to omni-directional antennas so they unable to avoid unwanted noise. Amplified antennas is of those ideas that "sounds good", but in practice is a bad idea. The exception to this is if the amplifier is attached to the base of a high gain directional antenna where it can avoid picking up the noise source in the first place.
Click to expand...
Of course if the signal is weak you are going to amplify noise as well.
I'm not familiar with over the air digital television.
At one time we used to pick up a distant station to watch NFL football. The television station was about 150 miles away but coming in over Lake Superior.
The analog signal was weak and snowy but watchable.
Now with digital, my understanding is you either get a picture or you don't.
Also atmospheric conditions play a part on distant stations.
My experience was that the signal was always best in the morning.
 
This is odd. I have a satellite dish but also a digital antenna for NFL games and misc. digital channels. While I have trouble receiving local CBS & ABC I have no problems with any of the 67 channels I get. The transmitters for CBS and ABC are in a location responsible for the trouble. But I do get them if I reposition the antenna or hold it with one hand. I live right off a street in second story condo and in a path for commercial air traffic heading to and from Bush Intercontinental Airport. I get none of the interference mentioned here so I wonder if the causes given here are the right causes.
 
Ironic you mention that ABC is one of the stations you have trouble with. I do too even with multiple antennas and trying just to get ABC. I'm lucking to get ABC 2 days in row when I try on purpose ignoring other channels. And for what ever reason on some channels with shows & movies with special effects those scenes always play blurry.
 
WhatInThe said:
Ironic you mention that ABC is one of the stations you have trouble with. I do too even with multiple antennas and trying just to get ABC. I'm lucking to get ABC 2 days in row when I try on purpose ignoring other channels. And for what ever reason on some channels with shows & movies with special effects those scenes always play blurry.
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What is the channel number? Is it a UHF station? If it's UHF you need a different antenna. If your antenna is a combined one that is supposed to pick up UHF as well you might need a more powerful dedicated UHF antenna. Or if it's a VHF station then a dedicated VHF antenna for that station. A Yagi antenna is highly directional and eliminates to a great extent any interference coming from the side.
Or there may be interference between the station and the antenna such as trees. The height of the broadcasting antenna might not be high enough for good reception. In this case raising the receiving antenna will help.
My only option is cable. Not enough stations close enough in the area to bother with over the air.
The apartment building doesn't allow satellite dishes.
 
Camper6 said:
Of course if the signal is weak you are going to amplify noise as well.
I'm not familiar with over the air digital television.
At one time we used to pick up a distant station to watch NFL football. The television station was about 150 miles away but coming in over Lake Superior.
The analog signal was weak and snowy but watchable.
Now with digital, my understanding is you either get a picture or you don't.
Also atmospheric conditions play a part on distant stations.
My experience was that the signal was always best in the morning.
Click to expand...
Electromagnetic waves at the VHF and UHF frequencies have some characteristics that greatly impact signal quality:

To begin with, they are easily reflected by metal objects and the interference that the OP described could well have been caused by intermittent reflection of the desired signal off of passing vehicles. The second reflected signal could arrive out-of-phase with the original signal and thus reduce the overall signal strength. This is not uncommon and military systems have to deal with it all the time, especially aboard ships where there is a lot of metal.

Signals at VHF and UHF frequencies are greatly influenced by the index of refraction of the air they pass through. The case where the football game signal is being received 150 miles away after passing over a lake is a classic illustration. The humidity and temperature over water can create a ducting effect that can bend that signal around the curvature of the earth and keep it at a higher that normal strength. Under normal (non-ducting) propagation, VHF and UHF signals travel in a straight line of sight and would go right off into space. This phenomena is fairly common over the Great Lakes.

I have seen equations that try to predict the range that a signal will travel over water and there were numerous factors: radiated power, transmitter antenna gain, receiver antenna gain, water temperature, time of day, humidity, antenna height above the water (sometimes lower is better), frequency, wind, and signal processing gain such as you get using a digital signal. Also a whole bunch of other stuff that I don't remember.

The difference between analog and digital signals is a matter of how they are processed. If you are watching an analog signal and it starts to fade, you are dealing with "graceful degradation." A digital signal is processed differently and the receiver has some ability to reconstruct the signal when it starts to get weak, ..... up to a point where it just gives up suddenly. There is no graceful degradation with a digital signal, you either have enough to process, or you don't.

I see a lot of ads for digital antennas and it is pure marketing. There is not difference between receiving a digital or an analog signal as long as your antenna covers that frequency range.

.... end of lecture LOL, and I threw out my notes on this subject two years ago.
 
Pecos said:
Electromagnetic waves at the VHF and UHF frequencies have some characteristics that greatly impact signal quality:

To begin with, they are easily reflected by metal objects and the interference that the OP described could well have been caused by intermittent reflection of the desired signal off of passing vehicles. The second reflected signal could arrive out-of-phase with the original signal and thus reduce the overall signal strength. This is not uncommon and military systems have to deal with it all the time, especially aboard ships where there is a lot of metal.

Signals at VHF and UHF frequencies are greatly influenced by the index of refraction of the air they pass through. The case where the football game signal is being received 150 miles away after passing over a lake is a classic illustration. The humidity and temperature over water can create a ducting effect that can bend that signal around the curvature of the earth and keep it at a higher that normal strength. Under normal (non-ducting) propagation, VHF and UHF signals travel in a straight line of sight and would go right off into space. This phenomena is fairly common over the Great Lakes.


I have seen equations that try to predict the range that a signal will travel over water and there were numerous factors: radiated power, transmitter antenna gain, receiver antenna gain, water temperature, time of day, humidity, antenna height above the water (sometimes lower is better), frequency, wind, and signal processing gain such as you get using a digital signal. Also a whole bunch of other stuff that I don't remember.

The difference between analog and digital signals is a matter of how they are processed. If you are watching an analog signal and it starts to fade, you are dealing with "graceful degradation." A digital signal is processed differently and the receiver has some ability to reconstruct the signal when it starts to get weak, ..... up to a point where it just gives up suddenly. There is no graceful degradation with a digital signal, you either have enough to process, or you don't.

I see a lot of ads for digital antennas and it is pure marketing. There is not difference between receiving a digital or an analog signal as long as your antenna covers that frequency range.

.... end of lecture LOL, and I threw out my notes on this subject two years ago.
Click to expand...
Thanks for the post. Very interesting analysis. As the signal over Lake Superior? It was stronger in summer than in winter and I'm guessing it was because part of the lake froze over.
And sometimes when there was hurricanes and storms, I would pick up signals from huge distances. One I remember was from Greensboro, North Carolina. The signal lasted about 4 hours. That's about 1758 miles in the air from where I live. I used to take pictures of the screen because people wouldn't believe me..
Yes I get a kick out of digital antennas. The old standby in your attic will work just as well maybe even better.
 
Camper6 said:
Of course if the signal is weak you are going to amplify noise as well.
I'm not familiar with over the air digital television.
At one time we used to pick up a distant station to watch NFL football. The television station was about 150 miles away but coming in over Lake Superior.
The analog signal was weak and snowy but watchable.
Now with digital, my understanding is you either get a picture or you don't.
Also atmospheric conditions play a part on distant stations.
My experience was that the signal was always best in the morning.
Click to expand...
The digital tv here reacts to the interference by freezing the picture, puts picture & sound out of sync, goes through periods where video goes to slow motion, pixelization of picture, skips a couple of seconds of audio at a time. It could be crystal clear for a minute then about 10 seconds at a time all the above. This is one of those nights where I thought I had the antenna positions figured out but too no avail haven't been able to watch an uninterupted hour of tv yet.
 
Interesting subject! I'm having a problem with my own aerial...which is mounted on the roof. The transmitter is on high ground but, even so, if you live in a valley it can weaken the signal. Fibre optics seem to be a better option, but it means switching provider.
Why can't someone invent a tv which has its own in-built aerial...surely that would lessen the problem?
 
I know for a fact ABC & CBS boost their signals at different times and days. Example is Sundays I can get ABC & CBS if I position the indoor antenna correctly.
 
I am using an indoor digital aerial as I am about 2 miles
from the large booster tower for South London, I also
have a little booster box that plugs in to the electricity.

Many years ago to cut down interference on a normal
rooftop antenna, we used to put 70 ohm resistors into
the line, maybe you could make one using a lamp holder
and a lamp but no electricity, put the aerial cable in the
main contact one and out the other to the TV set, try
different sizes of lamps/bulbs till you get a result

If nothing else it will give you something to do.

Mike.
 
My son has Verizon fiber bundle and it works beautifully. Where I live, we have regular Optimum and it's not too bad at all.
 

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