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Re: [RFI] Noisy Uninterruptable Power Supply (UPS)

To: RVZ <rlvz@aol.com>
Subject: Re: [RFI] Noisy Uninterruptable Power Supply (UPS)
From: gene gabry <gene75942@gmail.com>
Date: Mon, 12 Jun 2023 17:00:30 -0500
List-post: <mailto:rfi@contesting.com>
Hi Dick

I’m using an APC NS 1350 in my shack directly under the desk top. Computer, rig 
power supply and two monitors plugged into the unit. Zero noise. Rig is a K3S 
and I have a very low noise floor here, -140dbm, out in the country of TN. No 
noise spikes at all. 

73 Gene
N9TF

Sent from my mobile device. 

On Jun 12, 2023, at 2:50 PM, RVZ via RFI <rfi@contesting.com> wrote:

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@contesting.com writes: 
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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@gmail.com>To: RFI 
<rfi@contesting.com>Subject: [RFI] RFI on 15 meters at W9RE tracked down to 
home 0.37    miles away.Message-ID:    
<CAKtW65eYrO4+Hn7mgaWe9SunmDv3S02LcYPmJ0Um-H4wONcCGQ@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@gmail.com>To: Don Kirk 
<wd8dsb@gmail.com>Cc: RFI <rfi@contesting.com>Subject: Re: [RFI] RFI on 15 
meters at W9RE tracked down to home 0.37    miles away.Message-ID:    
<CAOftebM83=o_ySAKYmT6Gvz4puzkZOV9GFrc5pxprPRO3wvOSg@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@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@contesting.com> http://lists.contesting.com/mailman/listinfo/rfi>  
------------------------------ Message: 3Date: Sun, 11 Jun 2023 20:50:40 
-0400From: Don Kirk <wd8dsb@gmail.com>To: Alan Higbie 
<alan.higbie@gmail.com>Cc: RFI <rfi@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@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@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@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@contesting.com>> http://lists.contesting.com/mailman/listinfo/rfi>>> 
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