I often dial around the AM band just before midnight on my Sangaen 803. For the past couple of weeks I hear a very loud buzzing sound at 990, 1090, 1190 and 1290 Khz. I live in Connecticut and don't normally receive any stations on any of these freqs. I haven't done anything around my home that I'm aware of that would generate this type of noise. Seems strange that the problem would arise on evenly spaced frequencies right up the middle of the band. The only thing I am aware of in the area is the neighbor running a pump to relieve underground water pressure beneath his swimming pool. Its about 300 feet away from my receiver. I'm not sure if his use of the pump and my reception of the noise coincide and I can't ask him to shut the pump off, even briefly, or he might lose the pool. Any ideas what might be causing the interference?
AM Interference
- Thread starter JimTailor
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Try The Radio Elsewhere
To verify if it is the pump or not, take the radio on a little trip (at least a couple of miles away from where you use it when you are getting the interference) and try it out somewhere else and see if you get the same problem.JimTailor said:
nexus
Member
Any new street lights installed near your home lately? Or are you running any floresent lights? If so you might want to try removing them from electricity. See if the buzzing sound goes away.
Hi Jim and all,
First, switch off the house mains and see if it goes away, if it does it's inside your house so switching one breaker at a time will help localize it. Then unplug suspected appliances one by one BUT some like TVs and VCRs have a backup to retain programming during brief outages, this may be a bit difficult. Using the radio as portable will narrow it down considerably if it can't be found otherwise.
Nexus, flourescents, dimmers, street lamps and faulty power distribution hardware produce a buzz throughout the spectrum, not on specific frequencies. Touch control lamps do however, they are controlled by body capacitance detuning an oscillator and are notorious for prouducing RFI.
This is an odd one producing a signal every 100KHz, a new one on me. That however is a good clue as to it's source, what could operate in or below the AM broadcast band and produce harmonics every 100KHz? Being harmonics are multiples of the fundamental frequency there is a strong possibility the fundamental IS 100KHz. For example the bane of DXers is the TV set. The horizontal sweep circuit operates at close to 15.75KHz and that high power sawtooth wave is rich in harmonics every 15.75KHz across the band.
First, switch off the house mains and see if it goes away, if it does it's inside your house so switching one breaker at a time will help localize it. Then unplug suspected appliances one by one BUT some like TVs and VCRs have a backup to retain programming during brief outages, this may be a bit difficult. Using the radio as portable will narrow it down considerably if it can't be found otherwise.
Nexus, flourescents, dimmers, street lamps and faulty power distribution hardware produce a buzz throughout the spectrum, not on specific frequencies. Touch control lamps do however, they are controlled by body capacitance detuning an oscillator and are notorious for prouducing RFI.
This is an odd one producing a signal every 100KHz, a new one on me. That however is a good clue as to it's source, what could operate in or below the AM broadcast band and produce harmonics every 100KHz? Being harmonics are multiples of the fundamental frequency there is a strong possibility the fundamental IS 100KHz. For example the bane of DXers is the TV set. The horizontal sweep circuit operates at close to 15.75KHz and that high power sawtooth wave is rich in harmonics every 15.75KHz across the band.
nexus
Member
thanks for your observation mr know it all. They could of also added BPL to his local area which would effect those bands.
wesct
Member
JimTailor said:
does the noise stay on all of the time? or is it just at night?
the trip around the neighborhood might give you some clues after you shut down
the main circuit breaker in the house.
wesct
Hi again,
Nexus, if anybody is a know-it-all it is you, uninformed and ignorant of the characteristics of BPL interference. I suggest you go to www.arrl.org to download the recordings so you can correctly identify it. You will also learn the bands that it operates on and the AM broadcast band is NOT one of them.
Jim, nice that you have overlooked the obvious, you're not a fan of Sherlock Holmes. "The truth often hides in plain sight." and "Once you have eliminated the impossible what remains no matter improbable is the solution." are phrases you should remember. Just for good measure a psychologist once told me "Never try to make sense out of nonsense." Now that's out of the way take Eddie Murphy's advice, "Now it's time to get busy." and BTW, "Careful With That Axe Eugene" (Pink Floyd) when stalking the neighborhood with a portable radio. Just have a good explanation ready when the cops ask what you're up to. (;->)
Nexus, if anybody is a know-it-all it is you, uninformed and ignorant of the characteristics of BPL interference. I suggest you go to www.arrl.org to download the recordings so you can correctly identify it. You will also learn the bands that it operates on and the AM broadcast band is NOT one of them.
Jim, nice that you have overlooked the obvious, you're not a fan of Sherlock Holmes. "The truth often hides in plain sight." and "Once you have eliminated the impossible what remains no matter improbable is the solution." are phrases you should remember. Just for good measure a psychologist once told me "Never try to make sense out of nonsense." Now that's out of the way take Eddie Murphy's advice, "Now it's time to get busy." and BTW, "Careful With That Axe Eugene" (Pink Floyd) when stalking the neighborhood with a portable radio. Just have a good explanation ready when the cops ask what you're up to. (;->)
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