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Topic: Radio frequency interference |
Edward Dixon
From: Crestview Florida
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Posted 6 Feb 2022 8:51 am
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I live just North of Eglin AFB and close to a local airport and today I heard some strange noises coming from my studio monitors. I stopped and listened and it turned out to be a conversation between air traffic control and an aircraft.
Is there anything that I can do to prevent my gear from picking up those signals? I am not anywhere close to being an electronics expert so any and all help is greatly appreciated.
Ed _________________ "Faith don't need no second opinion." |
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Donny Hinson
From: Glen Burnie, Md. U.S.A.
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Posted 6 Feb 2022 9:51 am
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You can buy RFI/EMI filters cheap enough, and put them on whatever outlets you're using for your equipment. You can also have an electrician install one on your main breaker box, but that would be considerably more expensive.
But first, I'd try to track down what specific piece of equipment (or cabling) is picking up the interference, as it's possible it's not entering through an outlet or power line, but directly into one piece of equipment. Because if that's the case, a filter in the outlet or power line may not help you. |
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Jack Stoner
From: Kansas City, MO
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Posted 6 Feb 2022 10:53 am
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To add to what Donny said. A bad cable with broken/no ground can let in RFI. Some poorly designed or shielded piece of gear. Many potentials.
Most studio monitors are self powered, so that's a start. Disconnect any signal cable(s) and see if you still hear the tower. If not reconnect one cable at a time and see if it comes back. |
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Edward Dixon
From: Crestview Florida
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Posted 6 Feb 2022 11:19 am
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Thanks for the responses, I think/hope I killed it.
After reading Donnie's post I went back in the studio to take another look and think I found the problem. I just got a Kemper and started setting it up with my Strat and Tele then I found some profiles that sounded like they would be good for Steel. I unplugged the cable from the volume pedal of the steel that goes to the Steelaire amp and ran a cable over to the Kemper. This morning I plugged the VP back to the Steelaire but neglected to unplug the end of the cable going into the Kemper input. I just found this out when I went back in to preview more amps. I think the cable was like a 6 ft. antenna feeding into the Kemper. I hope that's what it was because it was the simplest fix I could hope for.
I hadn't seen Jack's post at the time but looks like he nailed it. _________________ "Faith don't need no second opinion." |
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Dennis Detweiler
From: Solon, Iowa, US
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Posted 6 Feb 2022 6:57 pm
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I had the same problem with a radio station coming through my amp at a studio. I changed the length of my guitar cable from volume pedal to the amp and that solved it. _________________ 1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Revelation preamp, Carbon Copy Delay and Hall Of Fame Reverb, Crown XLS 1002, 2- 15" Eminence Wheelhouse speakers, ShoBud Pedal, Effects Pedals. 1949 Epiphone D-8. |
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Bill Hatcher
From: Atlanta Ga. USA
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Posted 6 Feb 2022 9:08 pm
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next time you have that problem, take the cable and make a loop then continue on to the next input. sometimes the loop will stop the interference. done that plenty of times on gigs close to radio transmitters. |
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Jack Hanson
From: San Luis Valley, USA
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Posted 7 Feb 2022 7:14 am
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When I was a kid we lived close enough to 50,000 watt WDGY's tower field that sometimes it came in on the bed springs, and it was always audible in the background of our old Bakelite Western Electric telephone (remember them?). Kinda like Muzak. |
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Robert B Murphy
From: Mountain View, Arkansas, USA
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Posted 9 Feb 2022 10:41 pm Air Force Base RF noise
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I lived across the street from the Patrick AFB air traffic control radome. The radar gave a periodic meep meep as the antenna scanned past. The audio tone was actually the pulse-repetition-rate frequency of the GHz emission. Interference signals can get in through unshielded pickups, particularly single coils which dont't cancel the out-of-phase noise that two coils pick up. Lack of adequate shielding, either in the guitar or the amp, particularly in the low level signal areas means any noise induced is going to get amplified and bug you. If you have a perfect faraday cage around the entire rig, an arc welder next to it wouldn't bother you. Noise can get in on the power line but transformers are pretty good filters. Even so, on most of my amps I've installed those coil and cap input filters with the socket for the detachable power cord. _________________ Bob, small o. |
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Robert B Murphy
From: Mountain View, Arkansas, USA
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Posted 9 Feb 2022 11:04 pm
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Oh yeah, if you're under the flight path of the runway approaches, you can expect to get hosed down occasionally by some pretty powerful aircraft radars too. A friend of mine once cooked a semi-frozen turkey by putting it on a step ladder in front of their P3 on the tarmac at Thule, Greenland. They were not happy about being sent to Europe just before Christmas. Like the ATC radars, the aircraft will probably sound like a tone and temporarily mess up your cell phone, wifi, bluetooth... _________________ Bob, small o. |
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