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

Mike said:
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.
Click to expand...
A resistor in the line? That was from the good old days when they used twin lead to bring the signal in. The twin lead acted like an aerial on its own and caused ghosting and interference from whatever was running including any electrical motors around.
The twin lead was 300 ohm resistance. The modern coax cable is 72 ohm. So maybe that's why the resistor worked as a filter. It's not needed now because the coax is 72 ohms and connects directly to the television set. It's called impedance matching. The coax cable is designed with interference rejecting capability. it's a copper core surrounded by shielding material. It's supposed to bring in the signal with much less loss.
The best way to cut interference is to use a high gain, directional antenna cut for the frequency of the channel you are trying to pick up. A Yagi antenna rejects any signals coming from the side. The stronger the signal, the less interference.
Attaching picture of cables . On the rightis the twin lead. You don't see it anymore. On the left is the coax cable now used. Notice the shielding.TVCable.jpg
 

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That is interestin Camper, I never seen twin aerial wire,
the 70 ohm resistors that I used were on a coaxial cable
set up, if you split the aerial cable you needed 3 of them,
one for each cable and all the resistors joined together
at the end away from the cables a bit like a "Y".

Mike.
 
Mike said:
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.
Click to expand...
The purposes of that 70 ohm resistor were to reduce standing waves on the antenna cable and to prevent the first stage of the TV from being overdriven. An overdriven first stage can generate a lot of unwanted harmonics and intermodulation products.

I think that the resistance of an incandescent light bulb is about 2 or 3 Ohms so it would not have the same effect. More importantly, it would introduce a major impedance mismatch between the antenna and the TV's first amplifier stage. The signal loss could be significant.
 

Mike said:
That is interestin Camper, I never seen twin aerial wire,
the 70 ohm resistors that I used were on a coaxial cable
set up, if you split the aerial cable you needed 3 of them,
one for each cable and all the resistors joined together
at the end away from the cables a bit like a "Y".

Mike.
Click to expand...
I see. But now there are splitters you can plug into . They match everything up. This is an old one i had hanging around. I believe the insides have small resistors built in.
splitter.jpg
 
I don't think any of the above would work on a
digital signal, but maybe you are still getting an
analogue one, we don't have analogue here now.

Mike.
 
Camper6 said:
I see. But now there are splitters you can plug into . They match everything up. This is an old one i had hanging around. I believe the insides have small resistors built in.
View attachment 129881
Click to expand...
That is indeed a four way splitter and they do have resistors inside. The input is one the right hand side of the unit and the other connections are all outputs. Each output will only have about 20% of the original input power since there will be signal losses in those resistors.
 
I think those that are experiencing problems should give the manufacturer of their antennas. I am getting a feeling not all are indoor like mine. I bought three different styles and only the last one works. However the same type (I can't say it is the same manufacturer) in my bedroom gives me fits. Mine are the flat rubber like styles 11" X 9". The crazy thing is I can move my leg or arm or move around the room and it changes the reception. I can't understand auto spark plugs causing problems like they used to on radios many decades ago. I have my doubts here.
 
Mike said:
I don't think any of the above would work on a
digital signal, but maybe you are still getting an
analogue one, we don't have analogue here now.

Mike.
Click to expand...
Oh that would work on a digital signal because I am using the same type of splitter to send my cable to both my living room and my bedroom. It only has two outlets. One coming in and two going out.
But here's the thing about antennas. If you have an older antenna that was used for analogue the impedance is 300 ohms at the terminals. You need to connect a converter that will change it to 72 ohms for cable connections to the television set.
The newer antennas will have a connector.
We don't have analogue either anymore. All the newer television sets automatically are set for digital signals.
 
My indoor aerial is a "ONE for all", I think that they
are from Holland.

I also think that they are the only ones that are on
sale here, I didn't see another version for indoors.

Mike.
TV Arial.jpg
 
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Expanding on the subject. And antennas or aerials as they are called.

All the old television sets came with an antenna. They were called rabbit ears and they just had a hole where you could mount it on the set and you would be able to rotate it for the best picture.
Notice that it was connected with twin lead 300 ohm. You could buy an adapter to convert it to coax cable for the modern sets.
For channels 2 to 13 that's all you need. It might even work on other channels. I have no way of testing it.
You could extend the arms for the lower channels like channel two and collapse them for the upper channels.
In a strong signal area that's all you need.
I'm going to test it later on in the laundry room because I'm in an apartment and blocked from the local transmitting towers which are about 30 miles away by air.
So basically what that is called is a dipole antenna. You can make your own easily.
rabbit ears.jpg
 
My first TV aerial was home made in the early 1960s.
twisted flex opened out at he far end and hung on
the wall like a T, the other end still twisted was stuck
into the TV coax socket, no screening but it worked
and there was very little to no traffic on the roads.

Mike.
 
Chet said:
Describe in more detail what the interference looks like.
Click to expand...
Pixelization(bunch of tiny squares), freezing screen, audio/video out of sync, extremely glitchy including missing seconds and words or entire sentences of dialogue along momentary freezing of screen and frequently goes to no signal.

Many causes as Pecos and Campers noted. Fix one might not eliminate the other. Could even be my wireless device. Have a new 5G antenna about 2 miles away and a leased tower another 2 miles away with all sorts of signals. But the cars accelerating 1/4 mile down the road are the most puzzling.
 
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WhatInThe said:
Pixelization(bunch of tiny squares), freezing screen, audio/video out of sync, extremely glitchy including missing seconds and words or entire sentences of dialogue along momentary freezing of screen and frequently goes to no signal.

Many causes as Pecos and Campers noted. Fix one might not eliminate the other. Could even be my wireless device. Have a new 5G antenna about 2 miles away and a leases tower another2 miles away with all sorts of signals. But the cars accelerating 1/4 mile down the road are the most puzzling.
Click to expand...
It's not puzzling to me. The cars are made of metal. The signal is reflecting off the car bodies.
It could be reflecting off buildings. You need what is called a good line of sight. Your antenna and the transmitting antenna must be awfully low.
 
Camper6 said:
It's not puzzling to me. The cars are made of metal. The signal is reflecting off the car bodies.
It could be reflecting off buildings. You need what is called a good line of sight. Your antenna and the transmitting antenna must be awfully low.
Click to expand...
Funny thing is that most of transmission towers are supposedly in the opposite or different compass direction. The signals mostly come from the SE yet the accelerating cars are coming from the NW.
 
One thing to note is those accelerating cars must go over railroad tracks. I wonder if the vibration is doing something in the cars or tracks causing some kind of forced interference or power surge/frequency change from that area.

I will say some of the longer luxury cars seem to cause 50% of issue. Ironic it seems some of the more cube shaped SUV cause issues. At first I thought it had something to do with led light vs halegon or old filiment style bulbs but the interference isn't consistent in front of the house.
 
Mike said:
My first TV aerial was home made in the early 1960s.
twisted flex opened out at he far end and hung on
the wall like a T, the other end still twisted was stuck
into the TV coax socket, no screening but it worked
and there was very little to no traffic on the roads.

Mike.
Click to expand...
When we lived on a hill, we were able to get perfect reception with a coat-hanger stuck in the aerial socket.
 
WhatInThe said:
Pixelization(bunch of tiny squares), freezing screen, audio/video out of sync, extremely glitchy including missing seconds and words or entire sentences of dialogue along momentary freezing of screen and frequently goes to no signal.
Click to expand...
I have the same symptoms when the signal is weak on a particular station but not on others since each station has different signal strength. Are all your stations behaving the same?
 
We have cable TV only on the bedroom television. The small TV in the kitchen and the one in the living room are free TV using rabbit ear type antennas. The reception is pretty good on most days until the wind kicks up, then the channels cut in and out and I have to constantly adjust the antenna. Luckily I don't use those TVs too often, only when I'm busy doing something in those rooms.
 
Think about it.
Cable t.v. You buy it.
They pick up the television stations with equipment like satellite dishes, etc. and then send it along their cable network to your home.
Over the air, you have a homeowner doing their best with cheap equipment to pick up the signal from a transmitting tower without knowing the basics. It's actually quite a miracle isn't it?
 
The Pixelisation of the screen only happens when I
am in the normal TV channel, if I am in the HD ones,
the screen goes black till the vehicle passes.

Moving the aerial around 18" solves both problems.

I think that the stations that get interference are the
ones with a weaker output of their signal.

All of the BBC channels get interference, but as they
are nation wide suppliers they have lots of boosters,
so their signal doesn't have to be strong, a lot of the
more obscure TV Companies who have appeared in
the digital age also get it, some of them sound as if
they are coming from somebody's garage, or a small
office somewhere and you never see any presenters.

Mike.
 
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WhatInThe said:
Funny thing is that most of transmission towers are supposedly in the opposite or different compass direction. The signals mostly come from the SE yet the accelerating cars are coming from the NW.
Click to expand...
So now there you go and that's a significant clue.
The signal is bouncing off the cars and being transmitted to your television set. It's not really interference like static being generated by motors or spark plugs etc.
With t.v. and radio waves, that's happening on the time. Before digital you would have two images on the screen. One from the original source and one being bounced back from a building or whatever on the way to the set. It was called 'ghosting.'
 
The ghosting makes sense on several of the channels in particular. The only thing I will say the cars moving away don't produce the interference the approaching cars do(Car engine hoods the main culprit?)

This is a bad area in general. I think that new tower 2 miles away is really starting to affect things. Radio is tough here as well on both bands AM and FM. For the first time ever I got no signal message on digital car radio screen near a intersection with alot of utility poles. Then a preset channel played another channel's broadcast until a cleared an intersetion with a lot of power lines. That new cell tower is ironically about a 1 mile straight line down the road that same intersection.

Also one doesn't realize all the emf coming off electric devices but I've been using a compass when adjusting the antennas and noticed if it's placed too close to something like an antenna or a speaker wire it affects the reading and they're lower power using braided/twisted wire.
 
Aerials are strange things indeed, in the 1950s I had
a friend who was into short wave/ham radio and he
was able to speak to people in Canada, USA, Australia
and many other places very clearly.

One day in daylight he showed me his aerial/antenna
set up, it was huge, in his garden/yard, he had copper
winding wire, the stuff that you make a motor with, he
had two tall poles of wood at the bottom of the garden,
two large insulated hooks at the corners of the house
and lots of loops of the wire around all of them, one I
would think was about 120 yards round and he seemed
to have hundreds of them, inside where the radio was he
had a piece of plastic or bakelite rod that again was wrapped
in copper wire, he said that you can't have too much antenna
and when he plugged the outside section into has regular
radio, the reception was fantastic, this in the days when the
static was part of every programme, yet his was clear.

So maybe we should go back in time and wrap the trees in
copper wire, at the back away from traffic!

Mike.
 

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