Questions tagged [rfi]
Use this tag for questions regarding RFI (Radio Frequency Interference).
162 questions
1
vote
2
answers
111
views
Why am I seeing pure-tone noise a bit above 5299MHz on a BladeRF with no antenna connected?
For fun, I've been taking recordings with a BladeRF 2.0 indoors on various frequencies in the 5GHz band, and looking at them in inspectrum. By mistake, I took one set of recordings with a short cable ...
- 113
3
votes
1
answer
222
views
Repeating signal every 0.185 MHz on 1400 MHz region
So I’m analyzing the spectrum from my RTL-SDR setup and noticed a periodic feature repeating approximately every 0.185 MHz. I don’t use any LNA, just a simple RTL-SDR dongle and a Wi-Fi grid antenna. ...
0
votes
1
answer
153
views
How noisy are EcoFlow battery backup and power station products in HF?
I'm thinking about replacing some near-EOL UPSs with EcoFlow products (for one thing, they use LiFePo4 instead of lead/acid and so are smaller and lighter) but before doing so I was wondering if ...
- 1,099
1
vote
1
answer
197
views
Why is the USRP X310 spectrum noisy without an external bandpass filter?
I am using an Ettus X310 USRP with UBX160 daugtherboards to collect 100 MHz of instantaneous bandwidth at 3.1 GHz. When I run this setup without an external bandpass filter, the spectrum appears noisy ...
- 151
3
votes
1
answer
391
views
What is this interference?
When on a SDR, at LF, I saw a cluster of interference. A little researching told me they were LF broadcast stations. But wikipedia said most of them are decommissioned, so what is the noise? What ...
- 823
3
votes
2
answers
338
views
Grounding - Confused
Building a single-story house, my radio shack will be in a bedroom that my wife has graciously, without complaining, agreed to let me use. I am confused about grounding, the articles and advice I have ...
- 41
1
vote
4
answers
751
views
Running antenna parallel to steel fence: antenna effects and neighborhood RFI
I am moving into a 55+ community, relatively small lots, single story frame and stucco homes in close proximity to neighbors. However, one edge of the lot is parallel to a golf course and has a steel ...
- 41
0
votes
3
answers
341
views
Will antenna insulation protect from RF burns?
Will antenna insulation protect from RF burns?
I understand that antennas should normally be built with their insulation on. Will that insulation protect from RF burns? Up to what power level?
If not:...
- 301
1
vote
2
answers
131
views
Will a LPF filter on the transmitter prevent CW key clicks?
Reading about key clicks, it would seem that they are primarily caused by the fact that the square wave of turning the key on and off must, by definition, have higher frequency harmonics, which sound ...
- 301
1
vote
2
answers
418
views
What is this pulsating signal?
When scanning through UHF, I find that there are a few frequencies that made a sound similar to a fast drum (~300 bpm?) Here are a list of the frequencies:
451.200 MHz
454.280 MHz
more coming soon
...
- 823
3
votes
1
answer
94
views
Why does RFI demodulate to a buzz sound?
For RFI problems with audio equipment, why does a dead carrier often demodulate to the familiar mains 60 Hz buzz sound? This occurs on multiple audio equipment around the house. There are lots of ...
- 31
1
vote
2
answers
354
views
Amateur radio antennas cause static on a cell phone call
My neighbor is a Class 8 truck driver and he recently put up what appears to be a large antenna outside of his house. I assume it is an antenna for radio - sorry, I am not technical and I just moved ...
- 11
3
votes
0
answers
388
views
Strange interference - consistent series of beeps/chrips at frequencies 145-146 KHz apart
I'm new at Ham Radio, in fact still studying for Technician (so I can't transmit) but I purchased a used Icom IC-746, dipole antenna kit and most recently a Hexbeam antenna. The power supply is an ...
- 131
2
votes
1
answer
231
views
A passive splitter/combiner in full-duplex mode
We have an RF chain where a full-duplex radio transceiver with Tx and Rx port operating on different frequencies. These are connected to a single antenna (that can Tx and Rx) via a diplexer, so that ...
- 123
1
vote
2
answers
362
views
Does a grounding block on a Yagi antenna with a balun and coax feed have the potential to add signal interference?
I have a commercial UHF/VHF Yagi designed for TV reception, also used for 2 meter reception, that has been installed for years but seems lately there's increasing amounts of signal disruption.
I have ...
- 113