Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [rfi]

Use this tag for questions regarding RFI (Radio Frequency Interference).

146 questions
36
votes
14 answers

Can my neighbor's ham radio antenna be interfering with my internet signal or is my internet provider just throwing blame elsewhere?

My internet provider is telling me that an antenna on my neighbor's house, which he called a ham radio antenna, is interfering with my DSL internet signal. I'm not tech savvy at all, beyond what's necessary to function in today's world, so I'm…
Vanessa
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31
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6 answers

Can I reduce RFI/noise at the antenna?

Recently, the power was out in my neighborhood for an extended period of time. I fired up my HF rig using battery power and was amazed at the lack of noise across the HF bands. When the power grid came back online, the noise returned. The…
The Driver
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20
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2 answers

How to detect common-mode currents or “RF in the shack”?

Let's say we already know that if your antenna is not suitably constructed or connected then you can get current on the shield of your coaxial feed line which will flow through the shielding/grounding of your equipment, becoming “RF in the shack”,…
Kevin Reid AG6YO
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3 answers

How do I prevent radio signals from tripping a GFCI?

My wife woke up several nights by a metallic "thunk". It happened to be while I was talking on 10 meters and turned out to be the ground fault circuit interrupter (GFCI) on her hair dryer cord. Apart from the obvious answer of leaving it…
Peter KB1AVL
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11
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2 answers

How to reduce RF in the shack when using vertical HF antenna (no radials)

What can be done to reduce RF in the shack (riding back along the coax) when using a vertical 10M antenna (without radials due to space constraints)? The antenna is an IMax-2000 at 32' elevation (20' over roof) with a 125' coax LMR-400, SWR is under…
Ron J. KD2EQS
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11
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3 answers

How can I get rid of RFI coming from my house solar panel inverter?

The solar system on my house creates horrible rfi on all hf bands during the day when the sun is out, it goes away when it's not sunny. Any one got any ideas how to get rid of the rfi ? I already tried putting capacitors across the high voltage…
Andrew
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10
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4 answers

How to operate on HF if an AM transmitter is only 540 feet away?

I'm a General Class Licensee, and due to pulmonary disease I cannot operate voice. I am also about 540 feet from a 24/7 1 kW AM station. The signal is so pronounced that most audio devices in the house pick up the station. Every shortwave receiver…
Gordon C
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10
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4 answers

Real world performance of magnetic loop antennas?

I was investigating about magnetic loop antennas. In a paper about them I found some bold claims: and This almost sounds too good to be true, considering a lot of us hams are surronded by city noise and this paper claims the noise would be much…
hjf
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10
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3 answers

My neighbor is complaining about my transmissions, what can I do?

My neighbor has indicated that they can hear noise from their computer amplified speakers when I'm transmitting. We've done a few tests and it does appear that it's my transmitter that's causing the noise. I've performed some testing and determined…
Adam Davis
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9
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3 answers

Attic Dipole - Impact of Ethernet over CAT5/6

I've been thinking about putting 20m and 10m dipoles up in my attic (HOA), but I also intend to soon put some Ethernet cable to a WAP (with PoE) through the attic. I was intending to feed this with CAT5e cable because I have lots of it and it's…
William
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9
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3 answers

How can I reduce the noise coming in from an RTL-SDR dongle?

I've recently received an RTL-SDR dongle, and I'm picking up a lot of noise that is probably coming from my PC, especially a lot of "spikes" on the 2M band. I've already started using a USB extension cable instead of plugging the dongle into the PC.…
krzysz00 KF5SOQ
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8
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3 answers

What is the proper way to ground your station's antenna?

I don't understand how you would go about giving an RF ground to your antenna. Would it not become an additional radial and affect the signal? What is the proper way to ground your station's antenna?
David Anastasio
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8
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1 answer

S Parameters in HFSS

I'm new to HFSS Software and I'm trying to plot Scattering parameters for a dielectric resonator excited by a probe (shown in image). I know that the top cylinder has a higher dielectric than the bottom cylinder. I also know that the cavity is a…
JOHN
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8
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1 answer

Identifying regulations for interfering stations

I'm working on tracking down some 2m repeater interference, and I have identified that the offending signal is a spur transmission on a commercial pager service (that lands right on our repeater input frequency). How would I identify regulations…
W5VO
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7
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3 answers

Is 20m noisy, or do I have a lot of local interference?

I'm making my first ventures into HF with a Yaesu FT-450D and a homebrew 20 Meter inverted-V antenna a local ham helped me set up. I've noticed that the 20 Meterm band seems to have lots of background noise (QRN) everywhere in the band. The S-meter…
Adam KC0DAD
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