View Full Version : can CB antenna interfere with sat signal
Hi guys,
my nieghbour has a CB radio mast in his back garden which is basically in the direct view of my sat dish. im have a few problems with the channels glitching but it seems worse of a night (im guessing he maybe is using the radio during the evenings)
this week he has installed an even bigger mast
dont get me wrong, im not one to interfere with someones pleasure but if it is interefering, surley thats illegal somehow as i always thought that broadcasting equipment has its own channels so it therefore does not interefere with anything else.
your advice is much appreciated
here the mast he has in his garden
2841
it is very possible for a cb signal to interfere with satellite reception but it does depend on a few things.
such as the age of your tv, and the power output of his gear especially if he is using a burner to boost his power which is totally illegal.
have you asked any of your neighbours if they are suffering the same problem ?.
do you get the interferance on normal tv?
There are a few other factors as well. Are you getting interferance all the time ie; 24/7 or is it every few minutes or seconds. when does it happen all day evenings only and finally as G0EJL states above what about other TV in your hone. Answer all of these and you will get a more details answer.
regards Prioryman
Thats not a CB aerial but an amatuer radio aerial and as such use a much broader spectrum of the airwaves. He will be a licenced operator as well. The Home Office used to come down hard on operators years ago if they were causing interference with tv signals and probably still do but i have never heard of them causing interference with sat signals but this is not to say it dont happen. This person knowing what radio hams are like, could have thousands of pounds worth of equipment and probably wouldnt want to risk upsetting people by commiting something illegal.
Follow the advice of the previous posts and if possible try having a chat with him as whatever the outcome you might find the interference stops if he is doing something naughty. Your last resort would be the Home Office as they sort out these problems when it comes down to TV signal interference from radio hams but not sure about the situation regarding satellite signals, or even if they can cause interference with them.
cb's are far more likely to cause radio interference than ham radio's simply because as stated ham radio operators are licensed and breaching the rules of the airwaves can and does result in people loosing those licences. cb users on the other hand frequently use illegal radios to transmit on channels they should not and with the use of pre-amps aka burners they can easily transmit with more than 100 times the permitted power ( wattage ). obviously not all do but a very large proportion do.
you can also buy rf filters very cheaply from most hardware stores for a few quid that connect to your coax to shield your tv etc from rf interference but with newer tv's these are built in so not needed.
as said we need more information to give you any more detailed advice.
just to set the record straight.... the antenna in the picture is called a sigma 4 or its copy the Vector 4000, and its a CB aerial covering 25 - 30 megs (10-11 metres), it can be used on 11 meters for ham radio but there are more efficient aerials out there if the person was a genuine ham radio enthusiast.. but thats besides the point. As there is so much of a frequency difference between CB and satellite TV, I would imagine if it is definately the cause of your glitching its caused by RF harmonics, and so the rf filter route would be the thing to do.
z1
It won't interfere with the satellite signal as such but could easily interfere with the electronics in the tv or duo itself distributing the picture.
That is definitely a cber and not a radio ham ,no ham i know would just have one aerial limited to those bands,it would be one of many.
The chances are he is using high power ( illegal ) coupled with an illegal cb but then it could all be legit ,either way i would have a word with him ,i'm sure the last thing he would want is to be causing any kind of interference.
thanx for all the replies guys.
i spoke to hime about his previous antenna before i got my sat (was on cable previously), he told me he just talks to people from all over the country. i very much doubt he is licenced so i think that rules the 'ham' thing out. When i installed my sat, even though in based near liverpool i found it hard to get a decent signal from 28.2, 19 and 13e best i could get from 28.2 was 75% even though i have friends with sly that have around 95%. i new his antenna was basically directly in front of my line of sat wit the sats i have but didnt really think it would make that much differance. i have a fair few nights with alot of glitching on 13 and 19 abd a bit on 28.2. he has since upped his antenna so its even bigger now. still getting the glitching but it happens more during the night 7 till 11. so im guessing now thats when he is using it but its just a guess. i have a philips LCD tv that ive had 4 about 3 years with no probs, tvs upstairs no probs either as all where connected to cable tv
if your dish is directly in the line of site of his antenna that could be the direct cause of your problem. did you install it your self or pay a installer ? as any professional installer should have not installed a dish in direct line of site of a transmitter mast even a cb antenna.
i would try a RF filter see if that sorts things but it is the CBers legal obligation to ensure that his equipment in no way interferes with other radio equipment such as the police , fire service and including tv / radio broadcasts.
personally i'd give ofcom a buz as they are the ones responsible for policing the airwaves.
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Hmm, I think there is a bit more to this than meets the eye, if, and its a big if, his antenna had anything to do with it why can you only achieve 75% signal when he is not transmitting, he cannot talk 24/7 and if he was affecting your equipment it would only be whilst he was actually transmitting, it sounds to me that you have other issues such as dish alignment/LNB. try rechecking your setup whilst he is out and therefore not using his kit also check your cabling/connections as a loose connection can act as an aerial in itself and pick up all sorts including ground radiation.
One other thing is that there is no way a signal running at 27MHz within radio frequency will interfere with a 10+ GHz in the microwave range so you can rule out him affecting the incoming signal from the satellite itself.
Before you go reporting this guy fully check your system or have it checked by a local installer.
my father used to be a CB'er and have the exact same antenna and have a CB called a Cobra ( i think it was) , and it can cause interference with TV sets radio's etc, most CB'ers are very friendly and some do tend to lean towards the illegal side, but if you go ask if he would mind testing some interface tests, with you, i bet he would not mind at all, as the previous posts say the filers are very cheap compared to the fine and having his kit confiscated, i think he would gladly help you out buying you the necessary filters. as my father did those many years ago.
so go ask your neighbor, just be polite about it, and i am sure he will sort you out :)
One other thing is that there is no way a signal running at 27MHz within radio frequency will interfere with a 10+ GHz in the microwave range so you can rule out him affecting the incoming signal from the satellite itself.
Before you go reporting this guy fully check your system or have it checked by a local installer.
you would be exceptionally surprised at what is and is not possible.
if the CBer was using a burner for example he could easily be transmitting with a power rating of over 400 watts where the legal limit is only 4 watts. thats enough power to do some serious interfering. granted the interference is likely to be via poorly shielded coax rather than the satellite or tv them selves but any thing is possible.
for example i could nock up a transmitter in a matter of minutes with some simple house hold items that can paralize your satellite setup any time i chose.
If he is using an amplifier it could be a poor filtered cb type and will be transmitting harmonics all over the place then you might get it in the house wiring,it doesn't sound like thats whats happening though.
If the aerial is in direct line then that could be blocking the signal, maybe its boarder line and when it sways in the wind it could be causing the glitching.
Yes but the fact still remains that the interference will only occur if he is transmitting, the op has stated that he can get no more than 75% signal at any time which suggests the problem is elsewhere
Yes but the fact still remains that the interference will only occur if he is transmitting, the op has stated that he can get no more than 75% signal at any time which suggests the problem is elsewhere
again not necessarily as the op stated that his dish is in direct line of sight to the mast. that can likely cause the reduced signal during the hours the CB is not transmitting.
Yes but the fact still remains that the interference will only occur if he is transmitting, the op has stated that he can get no more than 75% signal at any time which suggests the problem is elsewhere
75% doesn't really mean much though,whats the dish/lnb, how long is the cable and the quality of it.
I agree though it doesn't sound like the actual transmission is causing the problem
again not necessarily as the op stated that his dish is in direct line of sight to the mast. that can likely cause the reduced signal during the hours the CB is not transmitting.
that mast is not big enough to block signal from all the sats the op has mentioned, they are too far apart even if it was sat within 2 feet of the dish
75% doesn't really mean much though,whats the dish/lnb, how long is the cable and the quality of it.
I agree though it doesn't sound like the actual transmission is causing the problem
Yes exactly what is the op's setup we dont know.
regardless of the source of the interference, the first thing i would recommend is to check the coax as low quality coax while cheap can cause you no end of troubles. once your happy with the coax you can move on from there.
regardless of the source of the interference, the first thing i would recommend is to check the coax as low quality coax while cheap can cause you no end of troubles. once your happy with the coax you can move on from there.
At least we can agree on that :D
At least we can agree on that :D
we probably agree on quite a few things but i have a background in radio eqpt and know full well that it can cause the type of interference the op has stated and more especially during the hours he stated. however until he gives us more details and checks a few things on his end we'd just go round and round in circles arguing the toss.
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