I think I have narrowed down the likely source of the noise I'm hearing to a newly installed variable speed AC unit. It has peaks 16 KHz apart, typical for harmonics from a VSD and it is cyclic.. on for a while/off for a while day and night.
As soon as I get a tinaSA unit (which BTW has a built-in step attenuator) I’ll start looking for it. I appreciate all the input. 73/161, Allen R. Brier N5XZ 1515 Windloch Lane Richmond, TX 77406 USA 713-705-4801 [email protected] From: William Schrader <[email protected]> Sent: Sunday, August 30, 2026 4:20 PM To: n5xz <[email protected]> Cc: Texas DX Society Texas DX Society <[email protected]> Subject: Re: [tdxs-list] Need assistance locating RFI interference Allen.. you'll need a step attenuator, if you don't already have one... Or, build one. I see that you can buy little brick attenuators that are 50 dB...I think those are not very helpful compared to a step attenuator. I happen to own a couple of HP ones--- one is 120 dB in 10 dB steps, and the other is 12 dB in 1-dB steps. I built one outta the Handbook years ago that is 10 dB steps using a bank of slide switches. If you go that route, be sure to build it into an RF tight box. On Sun, Aug 30, 2026, 11:19 AM n5xz <[email protected] <mailto:[email protected]> > wrote: Yeah, tinySA. Looks like a neat device. I might buy one, too. 73 Allen N5XZ Sent from my Galaxy -------- Original message -------- From: William Schrader via tdxs-list <[email protected] <mailto:[email protected]> > Date: 8/30/26 8:06 AM (GMT-06:00) To: Allen Brier <[email protected] <mailto:[email protected]> > Cc: [email protected] <mailto:[email protected]> Subject: Re: [tdxs-list] Need assistance locating RFI interference Update: I found on the Amazon site that they sell a "ruggedized" case version of the little spectrum analyzer-- It's $179, so about the same price. I've bought one--- Will be interested to see how it performs. 73 Tuna K2TNO On Sun, Aug 30, 2026 at 12:15 PM William Schrader <[email protected] <mailto:[email protected]> > wrote: RE: Bill's link to a spectrum analyzer on AMAZON--- you sent us the link to your purchase... I looked on their search box for "spectrum analyzer" and found it: SeeSii TinySA Ultra+ ZS406 Spectrum Analyzer, 73 Tuna K2TNO On Sun, Aug 30, 2026 at 8:33 AM Bill Wibker via tdxs-list <[email protected] <mailto:[email protected]> > wrote: Hi Allen, Something like this should be helpful; it's a handheld Spectrum Analyzer. https://www.amazon.com/gp/your-account/order-details/ref=dp_iou_view_this_order?ie=UTF8 <https://www.amazon.com/gp/your-account/order-details/ref=dp_iou_view_this_order?ie=UTF8&orderID=113-7282975-3405068> &orderID=113-7282975-3405068 I have one still in the box that I could send you. I'm in Paige near Bastrop. I'm guessing the amateur radio operators who participate in foxhunts at BVARC could help. Here's a video. https://www.youtube.com/watch?v=UMu5AhSg-TI <https://www.youtube.com/watch?v=UMu5AhSg-TI&list=PLF1q9GtpjOrZyZ1KpfXjyJyLAWy-WRvba> &list=PLF1q9GtpjOrZyZ1KpfXjyJyLAWy-WRvba I could ship it to you on Monday or Tuesday. I'm in San Marcos and the analyzer is in Paige. 73 Bill WI5P On Sun, Aug 30, 2026 at 1:44 AM <[email protected] <mailto:[email protected]> > wrote: All, I need some assistance tracking down some serious RFI in the area. This RFI was originally only seen on 17 and 15m but now has extended all the way from 30 thru 10 meters and coming from two directions. They just started in the last month or so. I am requesting the help from someone with a battery powered or mobile radio with a bandscope so that we can locate the sources. I don’t think these noises can be found with a standard AM radio. Rodney from Centerpoint was kind enough to help and indicated that the RFI appears to be coming from an adjacent neighborhood (Brazoswood Estates) but he could not pin down the exact locations. I’m attaching screen captures from my K4D. If they get stripped I can send the in a separate email. K4SCRNCAP0017/18 are approx.. bearing 320 deg. Spacing is ~ 16 KHz KRSCRNCAP0019 is approx. bearing 180 deg. Spacing is also ~ 16 KHz Other times I get spacing between peaks of 45 KHz as in K4SCRNCAP0024 bearing ~310 deg. I’ve noticed sometimes they do drift in frequency, other times they are fixed. If I could arrange with someone with a suitable radio then perhaps we could find the culprits. Not sure what I’ll do if these are emanating from local residences, I’ll have to cross that bridge when I get there (anyone have a good contact with the FCC?). Please contact me off list if you can help or post here if you recognize the waveforms. TIA, 73/161, Allen R. Brier N5XZ 1515 Windloch Lane <https://www.google.com/maps/search/1515+Windloch+Lane+Richmond,+TX+77406+USA?entry=gmail&source=g> Richmond, TX 77406 USA <https://www.google.com/maps/search/1515+Windloch+Lane+Richmond,+TX+77406+USA?entry=gmail&source=g> 713-705-4801 <tel:(713)%20705-4801> [email protected] <mailto:[email protected]> <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> Virus-free. <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> www.avg.com _________________________________________________________________ To unsubscribe or modify your subscription options, please visit: https://lists.tdxs.net/mailman/options/tdxs-list/bwibker%40gmail.com _________________________________________________________________ To unsubscribe or modify your subscription options, please visit: https://lists.tdxs.net/mailman/options/tdxs-list/wtschrader%40gmail.com -- This email has been checked for viruses by AVG antivirus software. www.avg.com
<<attachment: ~WRD0535.jpg>>
_______________________________________________ Brazos Valley Amateur Radio Club (BVARC) 🌐 Website: https://bvarc.org 🤝 Get Involved: https://bvarc.org 💡 Suggestions: https://bvarc.org/home/suggestions 👥 Member Roster: https://bvarc.org/roster.php Unsubscribe or Change Settings: https://bvarc.org/home/club-listserver/ _______________________________________________
