Jonathan, K6ATO recently e-mailed me:
On a recent 2m SSB net, I accidentally discovered that my dash cam was generating a world of RFI that would entirely swamp out all but the strongest signals (e.g. repeaters) — this RFI was not limited to one model. I made a video about this since it seemed of general interest.
I was getting amazingly poor performance on what should have been a decent auto antenna…. It was only because I parked the car and the camera shut off 30s after the ignition was killed that I figured it out. Total pain!
The video demonstrates the impact of the dashcam RFI on a QSO, a bit of debugging using some test equipment, and tests of three separate dashcams:
- REXING V1 2.4 (very very bad)
- DEXORS X5 (pretty bad)
- XF TIMES 3.0″ (ok)
That’s mind blowing…I’ve done battle with RFI sources in my mobile setups, but even they didn’t seem this pronounced. Do you suspect the camera’s themselves, or do you think it has more to do with the little USB power supplies? I ask because I have a phone charger I used to use in my car, until I figured out it was my noise source, and I know a lot of these cameras use a similar powe supply.
I would think it it would be the power supply. My case: A year ago I updated my modem to a Cisco DPC3010 DOCSIS 3.0 8×4 Cable Modem. Two weeks after it was on-line my AM radio had severe RFI pulsating about 30pps. I detuned a portable am radio so I could hear where it was worse thinking it was my incoming power because it was loud near my breaker box and at the front of the yard where the power comes in and louder at that end of the house. No RFI anywhere in the neighborhood. It was very loud near the new modem. When I unplugged it, the pulsing stopped indicating the new modem the culprit. A new one was sent and it solved the problem. I believe it was the power supply of the modem that went bad.
I had the same issue. I returned the camera to the point of purchase and gave up. Apparently there are dash cam systems which are very costly which don’t cause the issues, but I can’t justify forking out the extra price over the consumer versions…