{"id":45798,"date":"2020-10-07T09:39:26","date_gmt":"2020-10-07T13:39:26","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=45798"},"modified":"2020-10-07T09:39:26","modified_gmt":"2020-10-07T13:39:26","slug":"steve-tracks-down-the-source-of-persistent-radio-interference-and-gets-it-addressed","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2020\/10\/steve-tracks-down-the-source-of-persistent-radio-interference-and-gets-it-addressed\/","title":{"rendered":"Steve tracks down the source of persistent radio interference and gets it addressed"},"content":{"rendered":"
\"\"<\/a>

Photo via Unsplash<\/p><\/div>\n

Many thanks to SWLing Post contributor, Steve Allen (KZ4TN), who shares the following guest post:<\/em><\/strong><\/p>\n

\n

Tracking Down Radio Frequency Interference<\/b><\/h1>\n

by Steve Allen, KZ4TN<\/strong><\/p>\n

I first noticed the RFI in late November 2019 as a steady buzz at around S9. It was present over most of the high frequency spectrum. I waited until the second week of December to see if you would end on its own, no such luck. I put an HF rig in my truck and started driving around the area to see if I could find a potential source. About a quarter mile from my home is a 161 KVA substation operated jointly by the Tennessee Valley Authority and my local electrical utility. When I parked in the driveway outside of the gated substation the sound of the interference was very strong and blanked the HF spectrum. I called the phone number on the gate and after an explanation of why I was calling I was connected to a fellow radio operator. I explained the situation and he said he would bring the issue to someone\u2019s attention and get back to me.<\/p>\n

A week went by and I didn\u2019t hear back from the TVA. I called the person I spoke with previously and he said that the individuals that he spoke with questioned the validity of my findings. He was very helpful but said he didn\u2019t have much clout with the TVA, RFI investigations were not his area of responsibility. I told him I would be happy to meet with someone from the TVA and show them what I had found. I also said I would contact my local electric utility and see if they had an RFI detector so we could eliminate their equipment. My initial contact at the TVA said he would keep trying to get someone to take this issue on and work with me to investigate. I said I would call him back next week.<\/p>\n

I then called the local utility company and talked to someone there who was familiar with these kinds of issues. The local utility company owns the output side of the equipment at the substation. He told me he was going to perform an infrared (heat) inspection of their equipment at the substation mid January as part of their annual maintenance and will also check the low voltage utility lines near the substation. I told him that I didn\u2019t notice this RFI until after they had a power outage nearby. He said he would try and get over earlier and check the power lines that run along the streets and look into the power outage history for this area.<\/p>\n

All during this time I kept a daily log of the RFI including time of day, frequency effected and S unit level. I also logged the weather conditions. To eliminate the electronics in my house as a possible source I connected my transceiver to a 12 VDC battery and shut off the mains circuit breaker, the RFI did not change at all. I also visited the ARRL webpage that provide information on RFI including recordings of known RFI:<\/p>\n

http:\/\/www.arrl.org\/radio-frequency-interference-rfi<\/a><\/p>\n

The ARRL is the best source I have found in finding and fixing RFI.<\/p>\n

By December 27th,\u00a0 no word back from anyone. I assumed that they were off for Christmas but decided to write a letter to the TVA as a follow up to what had happened so far. In early January I received and email from one of the TVA engineers who said he would contact a field engineer who would contact me. The next day I received an email from the field engineer who said he was going to be in the area on another job but would meet me at the substation.<\/p>\n

So, of course as soon as I am making headway with finding the problem the RFI diminished to the point of not being a problem. By this time here in Northeast Tennessee the winter temps are in the 40s and the humidity is lower. For whatever reason, the RFI ended. I met with the field engineer and we agreed that if there is no RFI there is nothing to search for.<\/p>\n

Fast forward to August, 2020. In June and July I had been operating digital, mostly FT8. I usually had the volume control at zero and as it was summer I was doing no shortwave listening. One day I decided to tune around the bands and found that the RFI was back as strong as it was during December at S4-S9 from 2-30 MHz. I emailed the principal engineer I had previously been in contact with at the TVA and he told me he would contact another field engineer and that he would come to my house with an RFI locator and start a thorough investigation. The next day I received an email from the field engineer and we scheduled a time for him come over.<\/p>\n

Upon his arrival he connected his RFI locator to my vertical antenna and tuned across the spectrum. The locator immediately displayed the signal. He captured an electronic image and said that he could now drive around the area and try and find a match. A hour and a half later he called and said he was unsuccessful and wanted to come back\u00a0 and make sure the signal was still present. Sure enough, it still displayed on his locator and he was puzzled why he could not find a similar signal while driving the area. He said he would send a copy of the recording to the TVA engineer and get back to me.<\/p>\n

A few days later I heard back from him and he wanted to come over again and make another recording. I believe after discussing this issue with his supervisor he was going to use a different method of searching the area. After a couple of hours I received a phone call from the field engineer telling me that he thought he had found the source of interference. Using a parabolic antenna he had found two different utility poles that appeared to have defective lightening arrestors on them. Both are within a quarter mile of my QTH. These poles are the responsibility of the local electrical utility not the TVA. He said he would contact them and follow up with me in a few days.<\/p>\n

In a couple of days the interference was very low to nonexistent. Shortly thereafter the engineer contacted me saying the local utility company had completed the repairs and wanted to know if the interference was still present. I said I hadn\u2019t hear it in a couple of days and I would get back to him if it returned. A couple of weeks later I received an email from the field engineer detailing the incident, what he had done to locate the interference, and what was done to repair it. In his email he stated the service was provided at no cost by the TVA Right of Way and Elizabethton Electric Department through TVA\u2019s Comprehensive Services Program (CSP). I am so appreciative of the Tennessee Valley Authority. The airwaves are now free of manmade interference and I am looking forward to another winter of operating and listening to shortwave radio. Here in the 21st century there are so many electronic devices that are capable of causing RFI. I am very thankful that my station is RFI free (for the time being).<\/p>\n

Steve Allen, KZ4TN
\nElizabethton, TN<\/p>\n

\n

Thank you so much for sharing your story, Steve. Only recently, we posted Emilio’s article<\/a> about tracing interference to poorly made switching power supplies. Thank you for sharing how you approached your local utility company, in your case, to resolve your RFI!<\/strong><\/em><\/p>\n

Very encouraging! Readers note that you don’t always have to live with persistent RFI. If you know the source isn’t coming from within your home, sometimes it’s simply a matter of getting your local utilities company to investigate.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Many thanks to SWLing Post contributor, Steve Allen (KZ4TN), who shares the following guest post: Tracking Down Radio Frequency Interference by Steve Allen, KZ4TN I first noticed the RFI in late November 2019 as a steady buzz at around S9. It was present over most of the high frequency spectrum. I waited until the second […]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[545,627,3,43],"tags":[3842,2505,3898,2650,4089,2651,1296,453,2214,8865],"class_list":["post-45798","post","type-post","status-publish","format-standard","hentry","category-ham-radio","category-how-to","category-news","category-shortwave-radio","tag-am-noise","tag-how-to-filter-noise-from-shortwave","tag-mitigating-radio-noise","tag-noise","tag-qrm","tag-radio-frequency-interference","tag-rf-noise","tag-rfi","tag-shortwave-noise","tag-steve-allen-kz4tn"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-bUG","jetpack-related-posts":[{"id":52386,"url":"https:\/\/swling.com\/blog\/2022\/04\/egil-is-pleased-with-his-new-belka-dx-and-tecsun-icr-100-cases\/","url_meta":{"origin":45798,"position":0},"title":"Egil is pleased with his new Belka-DX and Tecsun ICR-100 cases","author":"Thomas","date":"April 7, 2022","format":false,"excerpt":"Many thanks to SWLing Post contributor, Egil (LA2PJ), who writes: Hi Thomas, In the middle of march, Steve Allen (KZ4TN) posted this article showing a case for the BELKA-DX. I found his idea so good that I ordered two of the small boxes, using the Amazon link given in his\u2026","rel":"","context":"In "Accessories"","block_context":{"text":"Accessories","link":"https:\/\/swling.com\/blog\/category\/accessories\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2022\/04\/Belka-DSP-DX-Case-1.jpeg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":61594,"url":"https:\/\/swling.com\/blog\/2025\/01\/hf-signal-enhancer-for-sdr-a-hands-on-build-by-steve-allen-kz4tn\/","url_meta":{"origin":45798,"position":1},"title":"HF Signal Enhancer for SDR: A Hands-On Build by Steve Allen (KZ4TN)","author":"Thomas","date":"January 11, 2025","format":false,"excerpt":"Many thanks to SWLing Post contributor Steve Allen (KZ4TN), who shares the following guest post: SDR Signal Enhancer by Steve Allen I came across this HF Signal Enhancer for SDR on the RTL-SDR.com website. It was designed and built by Peter Parker, VK3YE from Melbourne, Australia. Below is the link\u2026","rel":"","context":"In "Articles"","block_context":{"text":"Articles","link":"https:\/\/swling.com\/blog\/category\/articles\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/01\/STEVE-HEADER-1.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/01\/STEVE-HEADER-1.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/01\/STEVE-HEADER-1.jpeg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":30760,"url":"https:\/\/swling.com\/blog\/2018\/02\/can-you-help-luke-identify-this-radio-noise\/","url_meta":{"origin":45798,"position":2},"title":"Can you help Luke identify this radio noise?","author":"Thomas","date":"February 6, 2018","format":false,"excerpt":"Many thanks to SWLing Post contributor, Luke Perry, who writes: I am experiencing a issue with my shortwave reception at my part-time home. I have been helping out my mother so I have brought over my Sony portable, along with the Sony active antenna. I have a constant \u2018clicking\u2019 sound\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/02\/Sony-SW100-Dial-6160-Loomish.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/02\/Sony-SW100-Dial-6160-Loomish.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/02\/Sony-SW100-Dial-6160-Loomish.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/02\/Sony-SW100-Dial-6160-Loomish.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":34180,"url":"https:\/\/swling.com\/blog\/2018\/09\/arcing-can-produce-nasty-broadband-radio-interference\/","url_meta":{"origin":45798,"position":3},"title":"Arcing can produce nasty broadband radio interference","author":"Thomas","date":"September 21, 2018","format":false,"excerpt":"I mentioned in a previous post that, this year, QRM levels here at the condo in Qu\u00e9bec are higher on our balcony than they are inside the building. I think I found the source. A couple weeks ago, on my morning walk, I passed underneath some high voltage power lines\u2026","rel":"","context":"In "Ham Radio"","block_context":{"text":"Ham Radio","link":"https:\/\/swling.com\/blog\/category\/ham-radio\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/Elecraft-KX2-PK-Loop-Condo.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":25040,"url":"https:\/\/swling.com\/blog\/2017\/04\/advice-on-cancelling-locally-generated-noise\/","url_meta":{"origin":45798,"position":4},"title":"Advice on cancelling locally generated noise","author":"Thomas","date":"April 5, 2017","format":false,"excerpt":"An SWLing Post reader recently contacted me with the following question: \"What devices work well to cancel out local RFI? I've been told that both the Timewave ANC-4 and a number of BHI products are all worth considering.\" Unfortunately (or fortunately, for me) I've no experience with outboard DSP or\u2026","rel":"","context":"In "Accessories"","block_context":{"text":"Accessories","link":"https:\/\/swling.com\/blog\/category\/accessories\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/04\/Timewave-ANC-4.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/04\/Timewave-ANC-4.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/04\/Timewave-ANC-4.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":45271,"url":"https:\/\/swling.com\/blog\/2020\/09\/cant-receive-anything-on-your-new-shortwave-radio-read-this\/","url_meta":{"origin":45798,"position":5},"title":"Can’t receive anything on your new shortwave radio–? 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I am not really interested in FM, but I would like to listen to international stations on SW, utilities\u2026","rel":"","context":"In "AM"","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/PL-680-BBC-Click-Frequency.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/PL-680-BBC-Click-Frequency.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/PL-680-BBC-Click-Frequency.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/PL-680-BBC-Click-Frequency.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/45798","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=45798"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/45798\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=45798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=45798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=45798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}