[RFI] Noisy Uninterruptable Power Supply (UPS)

Mon Jun 12 15:50:23 EDT 2023

Hello RFI Group,
 I'm wondering if there is a commercially made UPS (Uninterruptable Power Supply) that is RF quiet, or more RF quiet, than the average?  I've used a variety of UPS units and all of them have generated a great deal of RF on the ham bands.  I'm currently using an EATON SP-750, and like the other UPS units I've had previously, it generates aprx. 2-3 S-units of noise on 80-10 meters.   If there aren't any quiet UPS units, what are the remedies for making making a UPS quieter on the ham bands? Thanks in advance for your recommendations. 73, Dick- K9OM       
In a message dated 6/12/2023 11:00:08 AM Central Standard Time, rfi-request at contesting.com writes: 
Send RFI mailing list submissions to    rfi at contesting.com To subscribe or unsubscribe via the World Wide Web, visit    http://lists.contesting.com/mailman/listinfo/rfior, via email, send a message with subject or body 'help' to    rfi-request at contesting.com You can reach the person managing the list at    rfi-owner at contesting.com When replying, please edit your Subject line so it is more specificthan "Re: Contents of RFI digest..."  Today's Topics:   1. RFI on 15 meters at W9RE tracked down to home 0.37 miles      away. (Don Kirk)  2. Re: RFI on 15 meters at W9RE tracked down to home 0.37 miles      away. (Alan Higbie)  3. Re: RFI on 15 meters at W9RE tracked down to home 0.37 miles      away. (Don Kirk)  ---------------------------------------------------------------------- Message: 1Date: Sun, 11 Jun 2023 19:56:26 -0400From: Don Kirk <wd8dsb at gmail.com>To: RFI <rfi at contesting.com>Subject: [RFI] RFI on 15 meters at W9RE tracked down to home 0.37    miles away.Message-ID:    <CAKtW65eYrO4+Hn7mgaWe9SunmDv3S02LcYPmJ0Um-H4wONcCGQ at mail.gmail.com>Content-Type: text/plain; charset="UTF-8" Mike (W9RE) has been experiencing RFI on 15 meters when beaming North butnot during hours of darkness.  By just driving around he located what hethought was the property generating the RFI using a K3 in his car with a 15meter mobile whip antenna.  Mike asked for my help to confirm his findingsusing my portable direction finding gear which we did yesterday, and I justuploaded a video documenting this case. I try to avoid guessing what the source of the RFI is, but at the moment weare very suspicious that a small grid tied solar system is the source ofthe RFI.  Mike will now follow up with the homeowner to identify the truesource of the RFI, and then what can be done to mitigate the RFI. For those interested here is a link to the youtube video:https://youtu.be/yD7U-nH-AAg 73,Don (wd8dsb)  ------------------------------ Message: 2Date: Sun, 11 Jun 2023 18:16:48 -0600From: Alan Higbie <alan.higbie at gmail.com>To: Don Kirk <wd8dsb at gmail.com>Cc: RFI <rfi at contesting.com>Subject: Re: [RFI] RFI on 15 meters at W9RE tracked down to home 0.37    miles away.Message-ID:    <CAOftebM83=o_ySAKYmT6Gvz4puzkZOV9GFrc5pxprPRO3wvOSg at mail.gmail.com>Content-Type: text/plain; charset="UTF-8" Hypothesis: Solar system.Next steps: (1) Ask neighbor if recently installed solar system. (2) HaveMike park his receiver on frequency of RFI spike 10 minutes before exacttime of sunrise - then continue until 10 minutes after SR.  (3) ask him toreport results back to you. 73,~ Alan K0AV On Sun, Jun 11, 2023 at 5:56 PM Don Kirk <wd8dsb at gmail.com> wrote: > Mike (W9RE) has been experiencing RFI on 15 meters when beaming North but> not during hours of darkness.  By just driving around he located what he> thought was the property generating the RFI using a K3 in his car with a 15> meter mobile whip antenna.  Mike asked for my help to confirm his findings> using my portable direction finding gear which we did yesterday, and I just> uploaded a video documenting this case.>> I try to avoid guessing what the source of the RFI is, but at the moment we> are very suspicious that a small grid tied solar system is the source of> the RFI.  Mike will now follow up with the homeowner to identify the true> source of the RFI, and then what can be done to mitigate the RFI.>> For those interested here is a link to the youtube video:> https://youtu.be/yD7U-nH-AAg>> 73,> Don (wd8dsb)> _______________________________________________> RFI mailing list> RFI at contesting.com> http://lists.contesting.com/mailman/listinfo/rfi>  ------------------------------ Message: 3Date: Sun, 11 Jun 2023 20:50:40 -0400From: Don Kirk <wd8dsb at gmail.com>To: Alan Higbie <alan.higbie at gmail.com>Cc: RFI <rfi at contesting.com>Subject: Re: [RFI] RFI on 15 meters at W9RE tracked down to home 0.37    miles away.Message-ID:    <CAKtW65ctNUhUQ_HWQ-8aQUsT7xH+wg1OETbTfWDx6NO6Qdw4ew at mail.gmail.com>Content-Type: text/plain; charset="UTF-8" Hi Alan, Just need to work with the homeowner to identify the source.  We haveutmost confidence the RFI is originating from their property (we tookdirection finding readings from all sides of their property) withouttrespassing on their property, and unfortunately we probably even gotinto poison ivy when we approached their back property line via an HOAretention pond. Mike has monitored the RFI for a long time and sees the RFI disappeararound Sunset.  Mike monitored it today but it was a very overcast daywhich turned into a rainy day.  Signal strength was very low early thismorning after sunrise and eventually came up in strength but not as strongas it was yesterday when it was a nice sunny day.  The system is a year oldand the homeowner said the system is not working (whatever that means) andthat the installer went out of business.  But again the only way to reallyprove it's the Solar System (or some other device) is to be able to turnthe RFI on and off by turning on and off the actual device causing the RFIand until that's done it will always just be a guess (maybe a good guess,but still a guess). The homeowners are elderly and were very suspicious of us when we talkedwith them in person (and rightfully so) and we therefore all decided itbest that the next step is for Mike to communicate with them via US mail(and then hopefully with them or a family member via phone) which willhopefully allow them to better understand the situation and the kind ofhelp we need from them, etc. Just FYI,Don (wd8dsb) On Sun, Jun 11, 2023 at 8:17?PM Alan Higbie <alan.higbie at gmail.com> wrote: > Hypothesis: Solar system.> Next steps: (1) Ask neighbor if recently installed solar system. (2) Have> Mike park his receiver on frequency of RFI spike 10 minutes before exact> time of sunrise - then continue until 10 minutes after SR.  (3) ask him to> report results back to you.>> 73,> ~ Alan K0AV>> On Sun, Jun 11, 2023 at 5:56 PM Don Kirk <wd8dsb at gmail.com> wrote:>>> Mike (W9RE) has been experiencing RFI on 15 meters when beaming North but>> not during hours of darkness.  By just driving around he located what he>> thought was the property generating the RFI using a K3 in his car with a>> 15>> meter mobile whip antenna.  Mike asked for my help to confirm his findings>> using my portable direction finding gear which we did yesterday, and I>> just>> uploaded a video documenting this case.>>>> I try to avoid guessing what the source of the RFI is, but at the moment>> we>> are very suspicious that a small grid tied solar system is the source of>> the RFI.  Mike will now follow up with the homeowner to identify the true>> source of the RFI, and then what can be done to mitigate the RFI.>>>> For those interested here is a link to the youtube video:>> https://youtu.be/yD7U-nH-AAg>>>> 73,>> Don (wd8dsb)>> _______________________________________________>> RFI mailing list>> RFI at contesting.com>> http://lists.contesting.com/mailman/listinfo/rfi>>>  ------------------------------ Subject: Digest Footer _______________________________________________RFI mailing listRFI at contesting.comhttp://lists.contesting.com/mailman/listinfo/rfi  ------------------------------ End of RFI Digest, Vol 245, Issue 1***********************************