Re: Topband: Local noise source identification
Thanks for all who responded with comments and suggestions in reply to my query. I will take them all into consideration during my quest to eliminate the source of my noise. I will also let you know the results. 73 Rick ve3mm On Sun, Nov 10, 2013 at 3:01 AM, Max Cotton airra...@dsl.pipex.com wrote: Check out UKQRM on google, plenty of information there including soundbytes. 73 Max M0GHQ _ Topband Reflector _ Topband Reflector
Re: Topband: Local noise source identification
Good luck, Rick! I expect that it will require a good bit of sleuthing to find the source(s) - but then, eliminating the source is another matter entirely, if it's coming from a neighbor! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Rick ve3mm Sent: Monday, November 11, 2013 10:48 AM To: topband@contesting.com Subject: Re: Topband: Local noise source identification Thanks for all who responded with comments and suggestions in reply to my query. I will take them all into consideration during my quest to eliminate the source of my noise. I will also let you know the results. 73 Rick ve3mm On Sun, Nov 10, 2013 at 3:01 AM, Max Cotton airra...@dsl.pipex.com wrote: Check out UKQRM on google, plenty of information there including soundbytes. 73 Max M0GHQ _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: Local noise source identification
Check out UKQRM on google, plenty of information there including soundbytes. 73 Max M0GHQ _ Topband Reflector
Topband: Local noise source identification
I am looking for suggestions to help identify a local noise that I am experiencing on topband. It's characteristics are; - bandwidth approximately 15 kHz - amplitude relatively constant - centre frequency seems to vary in small steps over time, no real pattern. - right now the centre frequency is 1819 kHz, it moves up and down up to 7 or 8 kHz. - does not seem to be present during the day. At least not this afternoon. I shut down all of the circuits in my house other than my shack and it did not disappear. Has anyone experienced something similar? 73 Rick ve3mm _ Topband Reflector
Re: Topband: Local noise source identification
I shut down all of the circuits in my house other than my shack and it did not disappear. Has anyone experienced something similar? Constantly. You took the right first step and determined that the noise source is external to your home. From here, the real work begins. Trying to get an opinion on the source is mostly a waste of your time. You'll need to get out and localize it with DF methods. I would start by searching the RFI list archives. http://lists.contesting.com/archives//html/RFI/ There's a lot of good information there to assist you with RFI source detection. While you're reading the information, keep in mind that methods, procedures and equipment used to find power line noise - and switch-mode noise is considerably different. Paul, W9AC _ Topband Reflector
Re: Topband: Local noise source identification
On 11/09/2013 05:15 PM, Rick ve3mm wrote: I am looking for suggestions to help identify a local noise that I am experiencing on topband. It's characteristics are; - bandwidth approximately 15 kHz - amplitude relatively constant - centre frequency seems to vary in small steps over time, no real pattern. - right now the centre frequency is 1819 kHz, it moves up and down up to 7 or 8 kHz. - does not seem to be present during the day. At least not this afternoon. I shut down all of the circuits in my house other than my shack and it did not disappear. Has anyone experienced something similar? 73 Rick ve3mm _ Topband Reflector Hi, I live in a four season resort and recreation area. Many of the 'neighbors' live far, far away and come here for short weekennds, long weekends, holidays , and vacations. When the population goes way up, mostly on the weekends, the intruding noises are almost sure to increase. Sometimes they wipe out parts of several bands and may last the entire vacataion'. Often, all or some of the interfering junk quiets when the visitors go to bed. I have been seeting up to operate on battery power during power outages. It's amazing how quiet the bands get when *THAT* happens evil grin. Short answer - yes - I have a signal just like that here. Probably a few others too. Ain't it wondeful? 73, Bill KU8H _ Topband Reflector
Re: Topband: Local noise source identification
Some switching power supplies are frequency-jittered to spread their spectrum and enable their host devices to meet FCC or Industry Canada line-conducted emissions limits. Also some of the newer lighting devices and cicuits can produce RF!! Y ou might try walking your neighborhood with a portable receiver and see if you can sniff it out. My bet is a switching power suppl y, based on your description. Good luck! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill Cromwell Sent: Saturday, November 09, 2013 5:44 PM To: topband@contesting.com Subject: Re: Topband: Local noise source identification On 11/09/2013 05:15 PM, Rick ve3mm wrote: I am looking for suggestions to help identify a local noise that I am experiencing on topband. It's characteristics are; - bandwidth approximately 15 kHz - amplitude relatively constant - centre frequency seems to vary in small steps over time, no real pattern. - right now the centre frequency is 1819 kHz, it moves up and down up to 7 or 8 kHz. - does not seem to be present during the day. At least not this afternoon. I shut down all of the circuits in my house other than my shack and it did not disappear. Has anyone experienced something similar? 73 Rick ve3mm _ Topband Reflector Hi, I live in a four season resort and recreation area. Many of the 'neighbors' live far, far away and come here for short weekennds, long weekends, holidays , and vacations. When the population goes way up, mostly on the weekends, the intruding noises are almost sure to increase. Sometimes they wipe out parts of several bands and may last the entire vacataion'. Often, all or some of the interfering junk quiets when the visitors go to bed. I have been seeting up to operate on battery power during power outages. It's amazing how quiet the bands get when *THAT* happens evil grin. Short answer - yes - I have a signal just like that here. Probably a few others too. Ain't it wondeful? 73, Bill KU8H _ Topband Reflector _ Topband Reflector
Re: Topband: Local noise source identification
I realize this won't help but I have a similar noise. Mine is about 24 kHz wide and drifts up/down considerably more than yours. The drift seems related to outside temperature. Here's the real kicker: it goes away every year immediately upon the coming of snow cover, but does not return until mid-summer sometime. This has been happening for at least five years now. I've tracked it to a group of 4 or 5 houses on the other side of a river, about 1000 feet from (some of) my Beverages. Sidebar: With a portable receiver I can also detect it re-radiating from my 100 foot vertical, which is 1500 feet from the source. Good luck, and let us know if you find it. 73, Paul N1BUG On 11/09/2013 05:15 PM, Rick ve3mm wrote: I am looking for suggestions to help identify a local noise that I am experiencing on topband. It's characteristics are; - bandwidth approximately 15 kHz - amplitude relatively constant - centre frequency seems to vary in small steps over time, no real pattern. - right now the centre frequency is 1819 kHz, it moves up and down up to 7 or 8 kHz. - does not seem to be present during the day. At least not this afternoon. I shut down all of the circuits in my house other than my shack and it did not disappear. Has anyone experienced something similar? 73 Rick ve3mm _ Topband Reflector
Re: Topband: Local noise source identification
Some of the line-conducted emissions can radiate from the power distribution circuits - especially with overhead service Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of N1BUG Sent: Saturday, November 09, 2013 6:29 PM To: Rick ve3mm Cc: topband@contesting.com Subject: Re: Topband: Local noise source identification I realize this won't help but I have a similar noise. Mine is about 24 kHz wide and drifts up/down considerably more than yours. The drift seems related to outside temperature. Here's the real kicker: it goes away every year immediately upon the coming of snow cover, but does not return until mid-summer sometime. This has been happening for at least five years now. I've tracked it to a group of 4 or 5 houses on the other side of a river, about 1000 feet from (some of) my Beverages. Sidebar: With a portable receiver I can also detect it re-radiating from my 100 foot vertical, which is 1500 feet from the source. Good luck, and let us know if you find it. 73, Paul N1BUG On 11/09/2013 05:15 PM, Rick ve3mm wrote: I am looking for suggestions to help identify a local noise that I am experiencing on topband. It's characteristics are; - bandwidth approximately 15 kHz - amplitude relatively constant - centre frequency seems to vary in small steps over time, no real pattern. - right now the centre frequency is 1819 kHz, it moves up and down up to 7 or 8 kHz. - does not seem to be present during the day. At least not this afternoon. I shut down all of the circuits in my house other than my shack and it did not disappear. Has anyone experienced something similar? 73 Rick ve3mm _ Topband Reflector _ Topband Reflector
Re: Topband: Local noise source identification
The switching frequency of switching power supplies can vary with the burden on the supply as well as ambient temperature. If it's sensitive to outdoor temperature could be the electric utility meters - most of those contain switching power supplies these days, and the meter's internal temperature tracks up and down with ambient temperature. Other candidates would be electric utility load control equipment, control electronics in heat-pumps etc., and electronics associated with satellite receivers. Good luck! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of N1BUG Sent: Saturday, November 09, 2013 6:29 PM To: Rick ve3mm Cc: topband@contesting.com Subject: Re: Topband: Local noise source identification I realize this won't help but I have a similar noise. Mine is about 24 kHz wide and drifts up/down considerably more than yours. The drift seems related to outside temperature. Here's the real kicker: it goes away every year immediately upon the coming of snow cover, but does not return until mid-summer sometime. This has been happening for at least five years now. I've tracked it to a group of 4 or 5 houses on the other side of a river, about 1000 feet from (some of) my Beverages. Sidebar: With a portable receiver I can also detect it re-radiating from my 100 foot vertical, which is 1500 feet from the source. Good luck, and let us know if you find it. 73, Paul N1BUG On 11/09/2013 05:15 PM, Rick ve3mm wrote: I am looking for suggestions to help identify a local noise that I am experiencing on topband. It's characteristics are; - bandwidth approximately 15 kHz - amplitude relatively constant - centre frequency seems to vary in small steps over time, no real pattern. - right now the centre frequency is 1819 kHz, it moves up and down up to 7 or 8 kHz. - does not seem to be present during the day. At least not this afternoon. I shut down all of the circuits in my house other than my shack and it did not disappear. Has anyone experienced something similar? 73 Rick ve3mm _ Topband Reflector _ Topband Reflector
