Well it seems most of the RFI we had here is gone.
Well it seems most of the RFI we had here is gone.
We had a second internet connection added about a week and half ago, i informed the technician that our landlord wanted the cable installed under the trailor.
That being said, he (the tech) replaced all of the cables and installed them under the home.
I had not checked for the RFI in the home until just last night. Wich leaves me wondering if my neighbors are so lucky? As for the noise outside the home and around the park, i cant figure that one out, most of the utilities around the park are underground until the come up the meters.
RFI fixed?
Rock95seven,
Interesting problem which you mentioned in your other post:
http://www.part15.us/node/1806
As I read your post, I had to wonder why the noise was on AM and FM. Usually electrical noise diminishes with higher frequency but a leaky cable system would explain what you reported since they are very broadband. Cable companies are pretty careful about leaks since they can get into FCC trouble and leaks also let signals into the cable system which can cause intereference. Perhaps you could call them and speak to a lead technician about this. The service dispatcher probably would not know what to do.
We also have underground utilities here and I never have RFI problems outside the house. I recall a few years ago that I would hear hum on my truck radio while driving on a nearby street which has overhead power lines. On wet nights I could see blue corona on one of their poles, called them to report, and they fixed it. I think my mention of blue corona got their attention.
Your RFI could also be coming from something one of your neighbors is doing or using. It will be interesting to know the source if you find it.
Also, it would help the readers here if you would put your similar topic posts in the same thread. This makes it easier for us to follow what is going on.
Neil
RFI
RF is a funny thing,
Not funny as in a joke but just odd.
I may have missed some powerlines that are on the road entering the park. But they seem to stop at a certain point and you can see the long metal conduit leading up the utility poles from underground. Could be a source of noise there too. I checked the car radio again, (factory stereo, am/fm cassette) i have a pontiac transport 97 model.
There is a bit of noise on that radio on am, wich sounds like frying bacon, probably from the sparkplugs and wires.
That reminds me, i need to get a tune up soon.
Anyway i use my car stereo alot for testing my transmitters as it has great sensitivity on both bands.
So most of the noise was removed after the new cables were installed by the cable company. My next objective will be to get to know some neighbors around me to see what kind of noise they have in their homes. then maybe address the issue with the power and cable companies.
I would’nt mind opening a thread on the forums about noise and their sources, one thing i think needs addressed in any community is the awful hash we get on radio equiptment at gas stations and some restaurants.
RFI Stories
I’ve noticed my Acer computer monitor puts out a fierce square-wave tone, about 500 Hz audiowise, at 150KHz on long-wave radio, with endless upper harmonics up into SW, out to maybe six feet. The compact-flourescents have a high buzz-factor when first turned on which seems to get less noticeable, but there are 2-lamps that somehow cause loud carrier hum to appear on radios tuned to my frequency everywhere in the house, which goes away when the lamps are switched off. On top of all that there are loud buzzes that last awhile, then disappear, as if something’s happening on the power-lines. I get a huge 2nd harmonic at 1700KHz from a 5kw station at 850KHz located one-mile away. I don’t have cable. Then that terrible digital racket on AM.
RFI
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Your “frying bacon” description is helpful. If it is sourced by the power lines this would indicate either a corona discharge on the high voltage (somewhere around 13.2 kV) distribution line or perhaps a loose connection somewhere in the power system. Corona can sometimes be seen if the humidity is high or if it is raining but usually it is heard on an AM radio.
If you hear this while mobile there could be a cause other than your ignition or electrical system, namely static created by the tires on the pavement. In the old days when AM was king manufacturers installed springs inside the bearing caps on the wheels which electrically connected the wheels to the axle. I haven’t seen these for many years. A real simple check for this is to note whether the noise stops when you stop the vehicle.
Neil
Another RFI Experience
This RFI experience is not related to the previous cases written about so far in this thread, but is yet another RFI experience worth sharing.
As was demonstrated on a recent Low Power Hour, the receiver for my Lectrosonics Wireless Microphone System, which operates at 184.3 mHz, was picking up strong RF from my 13.560 mHz dipole strung through the room. The audio being sent on shortwave reproduced with some crackle in the background every time I used the wireless mic. I thought that moving the dipole outdoors was going to be the only solution.
But I ran a test, and found that the RFI was still there when the wireless receiver was turned off! This could only mean that either the microphone cable running to the audio board or the power cord from the wall wart were the actual source of the interference.
For experiment, I wrapped the power wire four times through two stacked Radio Shake 273-104 Snap-on-chokes, and the RFI was totally gone. My oh my, that was easy.