FM Interference

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thunderspook

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Hello all,

I know this has been touched on with other cameras, but there seems to be nothing specific to this and no definitive answers for other cameras anyway.

I have just received my A118 from Foxoffer on eBay and I get very bad FM interference when connected to the cigarette lighter socket. Has anyone else had this problem and solved it? It's making it so I can't even listen to the radio most of the time in the car.

I have e-mailed Foxoffer but received no reply as of yet.

Thanks for any help,

Russ
 
What type of car, what type of antenna, how is the performance of your AM radio with and without the camera running?
 
I have interference from my BlueSkySea A118 and I'm not even using the supplied cigarette adapter. I'm using a piggy back fuse and 12v to 5v USB adapter.

On FM frequencies around 100-105 Mhz I hear a crackle/hiss around every 1 second. It doesn't make the radio unusable but is very annoying. When I disconnect the camera, the issue disappears.

I had the same problem with the cigarette adapter, so it's the camera causing the interference.

This is on a 2005 Skoda Octavia with the standard Stream radio.
 
Jokiin, it's a 2005 BMW 5 series, they have the sharkfin aerial on the roof.

We don't really do AM radio in the UK, mostly just FM. As soon as the camera turns off the reception is fine.

I haven't tried it without the power cable connected, I guess I could try powering it from a mains powered USB adapter at home to see if I get the same interference. I take it if the problem is the camera then there is no solution?
 
thunderspook said:
Jokiin, it's a 2005 BMW 5 series, they have the sharkfin aerial on the roof.

We don't really do AM radio in the UK, mostly just FM. As soon as the camera turns off the reception is fine.

I haven't tried it without the power cable connected, I guess I could try powering it from a mains powered USB adapter at home to see if I get the same interference. I take it if the problem is the camera then there is no solution?
Click to expand...

if you have a USB power bank it's good to power from as you can drive around with it connected and see how reception is affected, you may find it's something as simple as how the power cable is run depending on how the antenna lead for your vehicle is routed
 
I don't have one I can use in the car unfortunately, but I can try it while parked at home. I guess I could try powering it from my laptop while driving around.

I have tried running the cable a few different ways and it's always the same. I'll check tonight if it is different when powered using USB instead.
 
That is a good idea. I actually have a clip on ring lying here spare.

Didn't know why I didn't think of it before.
 
I tried it on the way home just powered by the battery and there was no interference at all. Next stage will be power it from the laptop I guess to prove its the power adapter.
 
might help to provide a better ground for the lighter or whatever your power adapter is using. ground loop noise is a real bugger sometimes, and it's very common when using stuff powered by the lighter socket. many automaker almost seem to go out of their way to provide dirty power to the lighter socket. even if a lighter won't actually work in that socket!
 
I put the ferrite ring on mine as close to the unit as I could, and it's made no difference. I'll try on some external battery power next to see if that helps on mine.
 
I had this problem on both our vehicles and managed to fix it after a fair bit of struggling.

Firstly, I replaced the power supply with one of these Wicked Chili usb power supplies:-
https://www.amazon.co.uk/gp/B004JEVIJUI'd read that this psu was highly rated in that it caused minimal interference.

Secondly, I replaced the power supply lead with this cable which is fully shielded:-
https://www.amazon.co.uk/gp/B0036ZRBFS
That might be enough but, if not...
If your 12 volt supply is a cigarette lighter type, it will have 2 large fins at the bottom that carry 12 volts in addition to the central 12 volt contact at the bottom of the tube. I found I got interference even when powering the camera by battery but it reduced by sticking my finger in the 12 volt cig' lighter hole and touched these fins. You can either replace the 12 volt socket with the non cig lighter type or remove it, wrap some insulation tape over where the fins are (the tube will have gaps in the side at the bottom that expose the fins) and then wrap aluminium tape along the length of the tube so that the fins have an earth shield.

If that's not enough...
The radio is subject to all sorts of potential problems through its power supply being shared by any number of other gadgets.
To get round this, run a fused lead directly from the battery to the radio ( this is always on and lets the radio remember its presets) and a further fused lead directly from the cars 'ignition on' wire from behind the fuse box to the radio (this turns the radio fully on with the ignition).
Finally, give the Radio its own dedicated earth supply by grounding it to the chassis with a good connection.

All the above is involved but it did work for me.

 
Last edited:
I think my issue might be because I'm using a cheap unshielded cable.

I'll see if I can buy a shielded cable
 
Thank you for all those suggestions. I was hoping not to have to buy my own power supply for it but I guess it looks inevitable. Rather rudely I thought, that's what Foxoffer suggested as well.

I ran some further tests on mine this evening, and interestingly I get the interference when running from battery if I have the USB cable plugged in, with nothing on the other end. As soon as I remove the cable from the camera the interference goes away.

Unfortunately my car is an E61 BMW 5 series, getting behind the dash is nigh-on impossible without a circular saw.
 
thunderspook said:
I ran some further tests on mine this evening, and interestingly I get the interference when running from battery if I have the USB cable plugged in, with nothing on the other end. As soon as I remove the cable from the camera the interference goes away.
Click to expand...

This indicates that the interference is being developed in the camera itself, not the charging circuit or the 5V adapter (though they could be adding to it when operational). This kind of interference cannot be easily addressed as it is an inherent design issue. Start with trying a few ferrite snap-on chokes placed on the USB cable together near the cam (not just one and not spaced out). Then try distancing everything cam-related as far as possible from the radio antenna, it's lead, and the radio itself. Also try sourcing the power from a different fuse/circuit. A shielded USB cable may help or may make it worse if the interference is on the grounded side of the cable. After all that the only simple fix would be to faraday-shield everything as much as is possible.

Manufacturers of consumer-grade electronics do not usually test or allow for RF interference issues beyond their finding it within legal limits for total RF emissions which can be all over the spectrum. To address these issues fairly well could double the cost of their products, so as long as they work fine for most people that isn't going to change. As electronics and RFI proliferate those regulations may change but don't hold your breath waiting.

Phil
 
My A118 interferes with DAB but is fine with FM. The camera isn't yet wired so the only source of the interference can be the camera itself. I am thinking of ditching the A118, night time video quality isnt that good anyway, and getting something else from a named manufacturer with a support structure rather than a no name god knows who trading from the back of beyond.
 
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The power adapter (12V to 5V USB) is also suspect. One member here who seems to know stated they are regulated by "switching" which is a major source of RF interference. Since almost every cam uses this type of power supply another cam may not solve the problem. One way to check for this would be to power the cam directly from a stand-alone USB power bank and see if the problem changes.

It seems that more and more people are having RF interference issues like this so I am going to do some testing with my G1Wc and Mobius and Anker USB adapter as soon as I can to see how well they do. More as this develops!

Phil
 
David106 said:
My A118 interferes with DAB but is fine with FM. The camera isn't yet wired so the only source of the interference can be the camera itself.
Click to expand...
DAB radios are susceptible to interference from LEDs - at least the cheap LEDs anyway. This may be the issue although I'm by no means certain.
 
I once tried an USB-Loader for Cigarette-Lighter-Thingy to run my A118 with... Unfortunatly, it overheated and got roasted... But no Interfearence when a Ferrit-Core has been placed 5 Zentimeter from the A118 (Camera-Side)...

I think the Problem is both in Camera AND in the PSU... Solution might be to hardwire the Camera... (that or the Manufacturer built a better shielding into the cams and replace our Models ;)
 
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