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Post by David on Feb 25, 2022 15:18:30 GMT -6
This is a follow up to my earlier post about longwave airport beacons. I've been using the Northern Utah SDR quite a bit lately, and it's surprising how many airports within the range of the SDR still have active LW beacons. So far, I've heard two beacons on the SDR during daylight hours, and at least six after dark. I was under the impression that most of the longwave beacons in the U.S. had been decommissioned at least a decade ago. Given the current world situation, it's probably a good idea to have some old school technology in place in case Russia decides to jam or disrupt GPS service in the U.S. I've already heard reports on radio network newscasts indicating that cyberattacks in the U.S. are a good possibility if Putin decides to unleash his cyber warriors on us.
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Post by kenglish on Mar 11, 2022 12:05:59 GMT -6
I'm starting to wonder if the "grinding tool" noise is actually coming from my close-by neighbor. I hear the noise coming from across the parking lot, too. Often, I hear it when the guy downstairs doesn't appear to be home... no lights (even when his blinds are open).
I am getting intermittent strong arcing noise, though. That seems to be coming from the direction of the vacant lot, where the huge office building burned in January 2021. They tore it down a few weeks ago, and now I hear noise near the underground feeders. Always had lots of noise in that block, for many years. Now, it's worse. I have to wonder if there was/is a long-standing issue with the feed. Last night, even with no snow, it was terrible.
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Post by David on Mar 11, 2022 17:48:23 GMT -6
Ken, I'm wondering if the arcing noise you're hearing is due to a power line transformer going bad, or an electrical cable with a bad connector or an open splice somewhere in the line. Have you tried finding the source of the arcing using a portable AM radio as an RFI "sniffer"?
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Post by kenglish on Mar 12, 2022 20:18:30 GMT -6
David, you got me inspired. Of course, the nice weather helped, too.
I took the ICOM, and the Wellbrook FLX loop antenna, plus a fiberglass surveyor's tripod, a 9 Ah battery and some filters around the corner.
The power-line related noise is coming from several poles on 900 East. There is a bit of noise on the pole at the corner of the lot where the office building burned down. The whole block feeds from that pole, condos, apartments and restaurants included, coming down the side and feeding an underground cable. I heard some noise on shortwave there a few weeks ago. It's noticeable on LW and HF bands. Probably conducted noise from the poles, in to the underground. The dirt blocks the higher frequencies.
The next pole, north, seemed to have a ton of noise. I thought that was the one that "Cowboy" hit a few summers ago, but I now think it was the next one. "Cowboy" is the nickname of a guy who is about seven feet tall, and usually dresses in full rodeo-cowboy regalia. He was drunk that night, and drove his tiny Subaru through the bottom of a huge transformer pole, leaving it hanging by the wires. I think this is the one, but the damaged pole was hidden from where my antenna was set up. I'll have to look at that from a different spot.
The intermittent arcing may be from across the street from the fire scene. It's a very old pole, and it is cluttered with old hardware. Someone hit the guy anchor while turning, and that spun the guy wire out of place, so that it rubs the street light circuit neutral wire. The tree limb pushes the wires together when the wind blows, or there is snow or water on it. (That explains why it happens in wet weather. Usually, gap noise goes away when the gap is wet.) The small battery was getting low, and it was nearing dusk. I'll try again tomorrow.
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Post by kenglish on Mar 12, 2022 20:39:16 GMT -6
Here's a link to what the NRAO guys at Greenbank use: www.gb.nrao.edu/IPG/I have many similar tools for power-related troubleshooting, mostly hobby-class or home-brew, not the professional Radar Engineers stuff. What I've discovered lately, using the spectrum-scope capability on the ICOM, is that much modern-day RFI is not wideband Gaussian noise (which is all across the spectrum, decreasing logarithmically as the frequency and distance goes up), but is often stuff like switch-mode power supplies, where the noise occurs at harmonics of the SMPS switching frequency, and ripples above and below those frequencies at the edges of the square wave. That's why one channel may be clear, and the next is obliterated. And, the frequency changes as the SMPS and the associated gear (like LED's) warms up. So, we have both wideband and frequency-specific power-related noise to deal with.
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Post by kenglish on Mar 15, 2022 23:12:46 GMT -6
Reported the issues from Saturday to RMP. They initiated a Trouble Ticket. Heard some more noise as the small rainstorm blew in tonight. OMG, I cannot believe how many guy wires and anchors are torn up. Seems like that area of 900 East is some sort of magnet for drunks and bad drivers. Found another one torn loose, dangling from the top of the pole. 😞
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Post by radiowyoming on Apr 10, 2022 12:57:08 GMT -6
I've got an Icom ic746pro sitting in the corner of our back room here at the radio station that I can't use because it's too noisy with all of our equipment and stuff nearby. My TEcsun and loops suit me fine outside.
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