Topband: Nasty QRM From ??

[fmoeves]

I see you mentioned you checked everything with the power off. I would look at utility poles maybe cable or fiber power supplies?? Also I have have had my sdr settings not correct and have seen what I thought was QRM... Maybe try another receiver? Good luck Fred KB4QZH 
-------- Original message --------From: Artek Manuals <Manuals at ArtekManuals.com> Date: 1/24/20  9:17 AM  (GMT-05:00) To: topband at contesting.com Subject: Re: Topband: Nasty QRM From ?? DickThere are many sources that can generate this kind of "noise" . More common of recent are variable speed blower motors in modern furnaces and central A/C units. Next are cheap switch mode power supplies from a plethora of items, manufactured in PRC. And finally outdoor lights that come on at dark (Both LED and Mercury Vapor)Since you have apparently killed all personal sources then it is likely coming from a nearby neighbor I have had them come from 1/2 mile away but not often . sources under a 1/4 mile are more likely. Tried� to look at your QTH on google earth but since you have multiple QTH's that wasn't possibleDaveNR1DXOn 1/24/2020 1:59 AM, Dick Bingham wrote:> Greetings All>> Here are my basic conditions:> - KiwiSDR (~DC-to-30MHz) or> - Apache-Labs 7000dle> - Dell laptop computer> - Both on battery power>> I have cleaned up my system using chokes and filtering to the point> there are virtually no CM-signals entering the receiver when the feedline> at the antenna is disconnected and re-connected to a 50-ohm load.>> When the antenna is reconnected I see desired signals PLUS an> unwanted comb-line with signals every ~98.4KHz (e.g. comb-lines span> 2573.49KHz to 4355.38KHz resulting in 98.438KHz line spacings.)>> These signals are frequency stable and not drifty. Shutting down the> house-mains with the receiver battery powered does not kill the QRM.>> SO, it looks like something somewhere is generating this junk that > runs from> the BC-band to >20MHz.>> Have any of you encountered similar ~98.xxxKHz spurious signals ?>> 73 Dick/w7wkr at CN97uj> _________________> Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector-- DaveManuals at ArtekManuals.comwww.ArtekManuals.com_________________Searchable Archives: http://www.contesting.com/_topband - Topband Reflector