Gadget interference -- any way I can shield it myself?

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justinicus

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I hope this is the right place to post... I searched the forums and found RFI posts all over the place! Unfortunately none of them seemed to cover 5VDC gadgets.

I have a Chinese dash cam (I think it's the i1000 as seen on dashcamtalk) which seems to be emitting interference. Does anyone know if it's possible to shield the device to eliminate it?

I was pretty happy with the camera until I got into amateur radio. I also have a Uniden BCT15X and a Baofeng UV-5R. Ordinarily, the camera is running whenever the car is on, so I didn't notice the difference for a while... One day, I happened to turn it off, and suddenly the HT and scanner lit up, signal coming through. I played with it a bit... as soon as it powered up, a strong signal got choppy and noisy, and weak signals were squelched out. Tried unplugging it, thinking it might be the power supply, but it's even worse when running off the battery (perhaps the power cable is grounding some of it out?).

Again, I'm picking up the interference on both a plugged-in mobile scanner and a battery-powered HT. My first thought was ferrite beads on the camera's power cord, but it wouldn't help much if I can pick it up on a battery-powered HT, would it? What about a pseudo-Faraday cage? Wrap everything but the lens in foil and try to find a place to ground it? Does that actually work?

Is there anything I can do besides ditching the camera?
 

n9mxq

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I'd bet it's the power supply. I'd try torroids on the power cord. I've noticed quite a few of my USB chargers will blank the AM/FM radio in my semi at work.. Which isn't a big deal when I'm sitting inside the Chrysler plant, but outside.. well..

They don't bother my 2ways or scanner..
 

justinicus

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But could it be the power supply if it gets WORSE when the power cord is unplugged from the camera?

I'll test it when I leave the office tonight, and try unplugging the power supply from the 12v socket. I should also try unplugging the rear camera -- it has a long, unshielded power/video cable snaked to the rear window.
 

n9mxq

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Unplug them one by one until you eliminate the interference.. Maybe some strange harmonics where one is partially cancelling out the others interference.
 

zz0468

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But could it be the power supply if it gets WORSE when the power cord is unplugged from the camera?
It could, if the power supply is unplugged from the camera but left plugged into a 12v power source. The power supplies on Chinese automotive toys are notorious for being noisy. It's start there.
 

justinicus

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Alrighty... update time.

I've confirmed that the interference is much worse when the recorder is powered up. Recording or standby makes no audible difference. Disconnecting the rear camera makes no difference. Disconnecting the power supply from 12V source makes no difference. Disconnecting ALL 12V adapters (cheap Chinese and otherwise) makes no difference. Car running, on on accessory, or off makes no audible difference.

The only think that makes a difference I can hear on my HT is powering down the recorder. Haven't gone out to buy foil yet (just moved into a new place -- don't have a properly stocked kitchen!)
 

pinballwiz86

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Alrighty... update time.

I've confirmed that the interference is much worse when the recorder is powered up. Recording or standby makes no audible difference. Disconnecting the rear camera makes no difference. Disconnecting the power supply from 12V source makes no difference. Disconnecting ALL 12V adapters (cheap Chinese and otherwise) makes no difference. Car running, on on accessory, or off makes no audible difference.

The only think that makes a difference I can hear on my HT is powering down the recorder. Haven't gone out to buy foil yet (just moved into a new place -- don't have a properly stocked kitchen!)
I have a Chinese dash cam
It sounds to me like that camera is radiating and your radios aren't shielded enough or the front ends are too hot. I know in my vehicle my Baofeng picks up the hum of the electric motor lowering the window and blanks out the audio.

Solution? Get a better quality dash cam. Trying to make a little Faraday cage might make for a fun project though!!
 
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