AVS Forum banner
Status
Not open for further replies.
1 - 7 of 7 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter · #1 ·
I'm having a nasty problem w/ c.b. radio interference. Crashes the party any time it feels like it. Yesterday I was at the computer and I thought my plasma display fell, it was so noisy. I jumped out of my chair got to my remote and turned down the volume fast.. Then it pitched so high I thought the tweeters were going to blow.


No doubt someone is illegally "breaker, breaker" braking the law in my neighborhood. I rode around for awhile looking for a mast. I did not find one.


I then went to the local Radio Shack to by 3 RFI filters to try to filter the noise. My outside antenna feeds 2 coax cables to my HDTV STB and then my 3rd cable is my Direct tv feed. After I put the filters on, then I lost some of my hdtv channels. Must have blocked signal too much or something? Maybe those only do analog filtering. So I took them off and got my stations back.


Only problem now is I am back to my unprotected state I started in. I am really afraid it is going to damage my equipment. If you could have heard the sound. It was awful.


Would appreciate any ideas anyone may have on fixes for this.


Thanks, Tom
 

·
Registered
LG 55" C9 OLED, Yamaha RX-A660, Monoprice 5.1.2 Speakers, WMC HTPC, TiVo Bolt, X1
Joined
·
45,683 Posts
Call the FCC; it's their job to resolve this type of problem.
 

·
Registered
Joined
·
44 Posts
Ken,


Good luck contacting the FCC. This type of complaint rates about as high the dust on the floor. With their limited enforcement staff, the most he can expect is to receive a "consumers guide to locating and eliminating interference". If he can identify a possible source, the FCC might send a letter to be suspected source of interference requesting a response to the complaint. This may or may not yield a responce. Only after multiple, repeated complaints, from more than one party, will the FCC escalate the matter to the point where they will investigate further. Unless the interference is life-threatening (ie: interference to law enforcement or aircraft communications), the FCC will not readily dispatch an engineer/investigator.


Unfortunately, a lot of the newer AV stuff lacks adequate shielding, and will rectify almost any RF signal in the air.


If you were unable to identify any kind of CB or HAM antenna in the neighborhood, keep an eye out for a mobile CBer passing thru your neigborhood.


His best bet is to identify the source and take the friendly approach. While this may not be what most AV enthusiasts want to hear, it will yield the best results. If it is a HAM, you will need to work together to come up with a solution. If it is an illegal CB operator, putting them on notice may be enough to get them to clean up their act and return to a legal power level. The law is that if the transmissions are within legal limits, then it is up to the equipment owner to solve their own problems.


If the signals are originating from a HAM operator rather than a CBer, approach the HAM operator with a friendly disposition, and he or she will most likely be willing to assist in correcting the situation. The HAM operator is under no obligation (FCC or otherwise) to stop transmitting due to the interference you are experiencing, as most likely they are emitting a clean and legal signal, but will most likely be polite and happy to work with you if approached in a non-demanding manner.


If the cause is a CBer, they may be running in excess of their legal power limit, and let them know you suspect such. While it is possible that even a 4-watt CB station could cause RFI, from your description, it seems as though they may be using an excessive amount of power. Likewise, a friendly approach will yield better results than a "demand" to stop transmitting.


I can understand both sides. While I am a HAM operator, I also am and avid AV enthusiast. Fortunately, I have been able to build a HT setup which allows my family to enjoy it when I get on the air. But I do have neighbors with their cheap AV stuff that experience problems every now and then.


It is sad that manufacturers try to save pennies by neglecting to add a few simple circuit designs which would prevent most RFI cases.


Sorry to be the bearer of bad news, but these are the facts. This has also been my observation after many years dealing with similar matters.


Good Luck,

Eric

KK2ED
 

·
Registered
Joined
·
70 Posts
Discussion Starter · #4 ·
in front of my system to eliminate this issue? I have no problem securing equipment to prevent this, only if I'm not throwing my money away on a "maybe it will fix it" situation.


Thanks, Tom
 

·
Registered
Joined
·
5,414 Posts
If you are actually hearing interference coming through your speakers while watching digital, the problem is not likely to be (only) coming from the antenna. Interference thru the antenna input of a digital system would usually just kill the signal, or cause lots of breakup....although it might cause lots of random pops and beeps in the audio, at the same time that the picture breaks up.


Try connecting the output of the DTV STB or the DBS receiver directly to a TV......i.e.:, have almost nothing else hooked up, just the antenna, STB, and a monitor. Anything else connected will add more "antenna" area to receive the interference. Then, see what happens. If you don't get interference, add another item, and wait to see if it gets bad again.


Interference can enter by three means:

Through the antenna, by means of their transmitter being on your frequency (splattering or off-frequency operation of their transmitter), or by front-end overload of your receiver (just too strong of a signal to your equipment.....the correct RF filter will help here).


By conduction of the strong signal into wiring, either the power lines or the audio/video/RF wiring. This can be cured by better shielding and connectors on the A/V/RF cables (or just cleaning and tightening the connectors), by a power line filter, or (often) just moving or re-orienting the equipment and its wiring.


By ingress of the signal directly into the equipment. This is a big problem with consumer equipment. Lack of shielding (metal cases, metal shield compartments around sensitive circuitry, de-coupling filters on various stages of circuitry are often left out to save costs) is usually the problem. The remedies for this range all the way from trying a different spot for the box to sit, to grounding the chassis, to adding shields and other components internally, to just plain re-designing or scrapping the model of equipment.....depending on the cost of modifications.


The very best stuff, like broadcast equipment (often designed to be used at a high-powered transmitter site), uses all three types of defense. Good shielding all around, built-in filtering on the power line and all inputs and outputs, and (if it has an antenna input) bandpass filtering to eliminate all but the desired band of frequencies from ever getting inside.
 

·
Registered
LG 55" C9 OLED, Yamaha RX-A660, Monoprice 5.1.2 Speakers, WMC HTPC, TiVo Bolt, X1
Joined
·
45,683 Posts
Quote:
Originally posted by KK2ED
Ken,


Good luck contacting the FCC......
These type of problems are the direct responsibility of the FCC. If everyone took your advice, of course they wouldn't bother responding; no one would call them. Check with your neighbors to see if others are also having the same problem, it does help if you have numbers on your side.


I had a problem with a local HAM operator and the FCC resolved the issue. Yes, I had to keep on them to get it done, but the system can work.
 

·
Registered
Joined
·
5,414 Posts
Unfortunately, the FCC has such limited resources that they usually cannot spend a lot of time on this type of thing. It's been my experience that a violator can "just say no", and walk away. In one instance, they finally had to go to the Mayor and get someone shut down on a "zoning violation".


Another problem is, when, the perpetrator can make trouble for you through your work (aka: retaliation).
 
1 - 7 of 7 Posts
Status
Not open for further replies.
Top