Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: interference - strong buzzing 18khz apart  (Read 7415 times)
KU8V
Member

Posts: 1




Ignore
« on: June 23, 2012, 02:50:06 PM »

all over 20, 17 and 15 is loud buzzing, spaced at precisely 18kz apart - at 14.190, .208, .228, .246. .264 et cetera.  I've gone on battery and cut off all my breakers and it is still there.  Comes in and out at seemingly random times.

Any clues?

Thanks,


David
KU8V
Logged
KC4MOP
Member

Posts: 743




Ignore
« Reply #1 on: June 25, 2012, 04:12:26 AM »

That is not easy to find. A neighbor with a Plasma TV?? A switching power supply nearby?? A battery charger for a cordless drill?? You'll have to investigate the sequence when this appears and start walking the neighborhood with a portable shortwave radio. Is it 24/7? What S reading of this buzz? Hopefully it is nearby.
Pre-amps on TV antennas can emit buzzes from switching power supplies. We had to trace one down for a 911 call center. And it turned out to be TV antenna pre-amp spewing all kinds of junk into the airwaves.

Fred
Logged
NI0Z
Member

Posts: 570


WWW

Ignore
« Reply #2 on: June 26, 2012, 08:40:45 AM »

What a nightmare for a ham!  I found my issue like that, it was an ionic pro air cleaners in my house.  They start out as a straight buzz and then start to slowly oscillate until they create a situation like you are describing.  Fortunately they were in my own home.

Best of luck and your portable shortwave radio is your friend on things like this.  I suggest driving a mile away and then see what happens as you drive back to your house.  If you see it more than a mile away then go further until it stops and work your way around until you find it.
Logged

KE7TRP
Member

Posts: 26


WWW

Ignore
« Reply #3 on: July 31, 2012, 03:50:58 PM »

I had this buzzing here and found it was a cell phone charger.  This is a switching supply.  It took out all of the high bands with a huge signal spaced apart on the icom.    Good luck on your quest.

C
Logged
W2MV
Member

Posts: 207




Ignore
« Reply #4 on: August 01, 2012, 11:03:30 AM »

It sounds like a switching p/s. Suggestion: try getting a general direction if you have a beam.
In any case, drive or walk around your neighborhood with a portable receiver. See if you can locate max sig strength and the source is probably close by.
Every innocuous part 15 device has the potential to cause the RFI you described.

Good luck.
Logged
W2MV
Member

Posts: 207




Ignore
« Reply #5 on: August 01, 2012, 11:11:23 AM »

Sorry, I forgot to mention that if you do have a directional antenna, using the (much deeper) nulls 90 deg to the main beam will generally provide a much better directional indication than the broad peak of the main beam.
Logged
HFCRUSR
Member

Posts: 139




Ignore
« Reply #6 on: August 01, 2012, 02:32:55 PM »

Maybe you already know of this but though I'd throw it in to help
http://www.eham.net/articles/8430

also if you can record and post the noise sometimes another ham who's IDd it can tell you what you have:)
Logged
K6RQR
Member

Posts: 213




Ignore
« Reply #7 on: August 13, 2012, 07:08:36 PM »

That website is 8 years old and I don't see that RFI help feature on it.
Logged
NX7U
Member

Posts: 56


WWW

Ignore
« Reply #8 on: September 06, 2012, 08:32:16 AM »

Like the other respondents--switching power supplies are everywhere. 
However, I have the same pattern you describe, from my heat pump compressor units.  They have a dual-speed fan and the speed control mechanism causes the RFI.
Logged

Scott NX7U in DM43
KD8HMB
Member

Posts: 138




Ignore
« Reply #9 on: October 16, 2012, 04:40:54 PM »

I had a similar problem for at least 6 months or so. The buzzing sound started at around 26.000MHz and extended up to 28.300 MHz or so, but only in the evening - never in the daytime. The buzzing sound would cycle on for roughly 40-50 seconds, then off for about the same amount of time. Today I happened to be out walking my dog early, before sun rise, and noticed that a street light in front of my neighbors house would go off and on in a similar cycle and wondered if this might not be the cause. Tonight I heard the buzzing again and went to the window and watched the lamp with the radio on. Light went off, heard buzzing noise. Light went on, buzzing stopped. I will put in a call tomorrow to the city and have them replace the light.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!