Advice please: Bad Radio Interference but only when dashcams are on!

Submariner1

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OK I got my repaired HK Amp back from repair.
All good or so I thought. And to some extent still do.

CD works perfectly and so does the Radio. When the car is starionery ign. Pos 1.

Went for a drive, and I thought I would check everything re recommendations to everyone.

Radio 2 sounded bad, so did Capital radio. i also Couldn't find a lot of stations, OK we dont have good radio here, but it was perfectly serviceable.

Went home terrible radio reception, could hardly find any stations.

End prognoses:
CD works perfectly all the time.

With the engine off, the Radio is crystal clear oodles of named stations.
Start the engine, and horrible interference, not engine whine, very weak reception noises, but only on the Radio.

Note I had wired in a dual USB port, from the rear cigar lighter for the Dashcams..
Heres the odd one, remembering on a dash cam forum someone mentioned radio interference with a dashcam.

So, pretty dispondent, I unplugged both dash cams, perfect Radio sound, reception and loads of named stations starionery or driving!
So I tried it stationery, engine off, Ign. Pos 1. great reception! All stations visible.

Switch to Ign.2 on come the Dashcams. On comes the interference and partial loss of stations!
Unplug the Dashcams one by one, interference reduces, with one disconnected, remove the other dashcam USB cable from the USB port and Radio recovers perfectly, and all stations circa 20+ all come back! no interference. :)

So I assume, the USB power charger circuitry is all fine. I.e. everything works perfectly in the Mercedes as long as the dashcams are not powered!

Note one USB cable goes along the centre console and up the A Pillar and to the centre of windscreen.
And the other goes across rear parcel shelf and curves up right near the rear windsheild Ariel!

Q. I feel BBA did repair the Amplifier and Tuner properly, and its all down to these dam dashcams! Note they didn’t find any fault with the Radio Tuner element. Would you agree?

Here is the real pig! I bluntly NEVER listen to the Radio. So I dont know whether the Dashcams actually caused interference to the Radio before I had Amplifier intermittant problems.

I even stated in my Amp problem threads, that mine was not the usual issue of loosing Station Names, but then later, I stated maybe 15% of the time the Amp. started to work, that I lost Radio station names.
I now suspect, this could well have been, when I was testing it when it distorted, to see if it had lost radio stations. I.e. thats the time I unusually used the Radio. And only some of the testing times did I start the engine (activating the Dashcams).

Has anyone heard of dashcams causing serious radio reception problems?

Is my logic right, that its unlikely the Amp repair could have effected the ability to reject radio reception Interference , especially as they found no fault with the radio tuner, so would logically have not touched that part.


As I never listen to the radio, this doesn't cause me any inconvenience regarding the dashcams.
Just want to be sure the Amp was repaired properly, which I am 98% sure it was.

Rear dashcam location
4E155F46-62C5-4218-988C-1DC51FDABB39.jpeg
 
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DelDrew

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OK I got my repaired HK Amp back from repair.
All good or so I thought. And to some extent still do.

CD works perfectly and so does the Radio. When the car is starionery ign. Pos 1.

Went for a drive, and I thought I would check everything re recommendations to everyone.

Radio 2 sounded bad, so did Capital radio. i also Couldn't find a lot of stations, OK we dont have good radio here, but it was perfectly serviceable.

Went home terrible radio reception, could hardly find any stations.

End prognoses:
CD works perfectly all the time.

With the engine off, the Radio is crystal clear oodles of named stations.
Start the engine, and horrible interference, not engine whine, very weak reception noises, but only on the Radio.

Note I had wired in a dual USB port, from the rear cigar lighter for the Dashcams..
Heres the odd one, remembering on a dash cam forum someone mentioned radio interference with a dashcam.

So, pretty dispondent, I unplugged both dash cams, perfect Radio sound, reception and loads of named stations starionery or driving!
So I tried it stationery, engine off, Ign. Pos 1. great reception! All stations visible.

Switch to Ign.2 on come the Dashcams. On comes the interference and partial loss of stations!
Unplug the Dashcams one by one, interference reduces, with one disconnected, remove the other dashcam USB cable from the USB port and Radio recovers perfectly, and all stations circa 20+ all come back! no interference. :)

So I assume, the USB power charger circuitry is all fine. I.e. everything works perfectly in the Mercedes as long as the dashcams are not powered!

Note one USB cable goes along the centre console and up the A Pillar and to the centre of windscreen.
And the other goes across rear parcel shelf and curves up right near the rear windsheild Ariel!

Q. I feel BBA did repair the Amplifier and Tuner properly, and its all down to these dam dashcams! Note they didn’t find any fault with the Radio Tuner element. Would you agree?

Here is the real pig! I bluntly NEVER listen to the Radio. So I dont know whether the Dashcams actually caused interference to the Radio before I had Amplifier intermittant problems.

I even stated in my Amp problem threads, that mine was not the usual issue of loosing Station Names, but then later, I stated maybe 15% of the time the Amp. started to work, that I lost Radio station names.
I now suspect, this could well have been, when I was testing it when it distorted, to see if it had lost radio stations. I.e. thats the time I unusually used the Radio. And only some of the testing times did I start the engine (activating the Dashcams).

Has anyone heard of dashcams causing serious radio reception problems?

Is my logic right, that its unlikely the Amp repair could have effected the ability to reject radio reception Interference , especially as they found no fault with the radio tuner, so would logically have not touched that part.


As I never listen to the radio, this doesn't cause me any inconvenience regarding the dashcams.
Just want to be sure the Amp was repaired properly, which I am 98% sure it was.

Rear dashcam location
View attachment 42231

You could try putting ferrite rings on the power cables, that might help with interference. Maplins sell a wide variety of them for different cable thicknesses.


Sent from my iPhone using Tapatalk Pro
 
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Submariner1

Submariner1

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You could try putting ferrite rings on the power cables, that might help with interference. Maplins sell a wide variety of them for different cable thicknesses.


Sent from my iPhone using Tapatalk Pro

Thanks I will.
 

L John

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Try powering dash cams from an external battery.
That will show if the interference is through the wiring or transmitted over the air.
 

Ken_R

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I'd also look at that dual port USB adapter. Have you got a laptop that you could take out to car and use that's USB socket to power each camera in turn?
 

Craiglxviii

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Agreed on the USB socket. You need to find the RF interference. Could of cable, is it would around anything? You might need to screen it.
 
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Submariner1

Submariner1

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Try powering dash cams from an external battery.
That will show if the interference is through the wiring or transmitted over the air.

Great idea, I have a 2000mA battery pack.
Nice one
 
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Submariner1

Submariner1

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I'd also look at that dual port USB adapter. Have you got a laptop that you could take out to car and use that's USB socket to power each camera in turn?

Good idea
Just got some feedback from a Dashcam forum saying its a notorious problem.

Really threw me with my non classic amplifier failure.
There was I thinking the very occaisional loss of station names must be the classic failed Tuner in the Amp issue.
Where I am pretty convinced, it was probably me switching over to the radio occasionally to see if I had lost the station names, when the car was running. And actually it was the dashcams all along.
 
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Submariner1

Submariner1

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Agreed on the USB socket. You need to find the RF interference. Could of cable, is it would around anything? You might need to screen it.

Yes, must find it.
I thought these were screened USB cables . i will check.

One for you Craig please.

As I never listen to the radio, only the CD.
I assume if I am not listening to the Radio, ( and therefore not hearing it ) it can’t cause any damage to the Tuner or Amplifier can it?
I Cant see how it could, but thought I would check.
 

flowrider

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The issue is normally with the dashcams psu, they generally are cheap, unshielded rubbush. I changed mine with quality usb adapters and usb cables.
 
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Submariner1

Submariner1

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The issue is normally with the dashcams psu, they generally are cheap, unshielded rubbush. I changed mine with quality usb adapters and usb cables.

Hmm I bought a reasonably priced USB dual port and allegedly quality USB cables.
But the were not well known brands. .

JuicEBitz 4m [20AWG Pure Copper] USB to Micro B Right Angle 90 Degree [L Shape] Fast Charger Data Cable Lead for Android Phones & Tablets, Samsung Galaxy, HTC, LG, Nokia Lumia, Sony Xperia, Nexus, BlackBerry and More (4m, Black) https://www.amazon.co.uk/dp/B01M70GQUX/ref=cm_sw_r_cp_tai_m6yUAbSZM94JK

And

GEREE Universal Rocker Style Car USB Charger - with Blue LED Light Dual USB Power Socket for Rocker Switch Panel https://www.amazon.co.uk/dp/B01J9QA1MC/ref=cm_sw_r_cp_tai_U.yUAbJJ3T056
 
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flowrider

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Hmm I bought a reasonably priced USB dual port and allegedly quality USB cables.
But the were not well known brands. .

JuicEBitz 4m [20AWG Pure Copper] USB to Micro B Right Angle 90 Degree [L Shape] Fast Charger Data Cable Lead for Android Phones & Tablets, Samsung Galaxy, HTC, LG, Nokia Lumia, Sony Xperia, Nexus, BlackBerry and More (4m, Black) https://www.amazon.co.uk/dp/B01M70GQUX/ref=cm_sw_r_cp_tai_m6yUAbSZM94JK

And

GEREE Universal Rocker Style Car USB Charger - with Blue LED Light Dual USB Power Socket for Rocker Switch Panel https://www.amazon.co.uk/dp/B01J9QA1MC/ref=cm_sw_r_cp_tai_U.yUAbJJ3T056
The cables look ok but I haven't seen the USB adapter before. Does your car have a rear 12v socket that you can try a standard USB adapter with. The adapter I use is....
https://www.amazon.co.uk/Charger-Ad...pID=418GG10LxML&preST=_SY300_QL70_&dpSrc=srch
 
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Submariner1

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The cables look ok but I haven't seen the USB adapter before. Does your car have a rear 12v socket that you can try a standard USB adapter with. The adapter I use is....
https://www.amazon.co.uk/Charger-Ad...pID=418GG10LxML&preST=_SY300_QL70_&dpSrc=srch

I do have a std. USB charger insert for a MB 12V socket
AUKEY Car Charger 24W / 4.8A Ultra Compact Aluminum Car Adaptor for iPhone X / 8 / 8 Plus / 7, iPad Air / Pro, Samsung Galaxy S8, HTC 10, Nexus, LG G5 / G6, Tablets and more (Grey) https://www.amazon.co.uk/dp/B06XFMFGY4/ref=cm_sw_r_cp_tai_s6HUAbPGR895W

The only std. rear 12V charger is in the boot.
I might have to buy a longer cable to reach from the front 12v socket.
Wont be much of a test if I looped it along the rear wing and through the rear window :)
 
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Submariner1

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I tried it using my TQKA 5V 2000 mA Battery pack.
As soon as the power hits the dash cams the radio gets horrible interference.

Admittedly I am Not very good with electrics, OK hopeless.
But I therefore feel its not the 12v to 5V USB charger socket. As it sound pretty much the same strength of interference using the battery pack.

By deduction its either something in the dashcams, or its radiating along the USB Cables. Or both.

I thought of unplugging the USB cable at the rear dashcam end, and switching the power button on.
Would doing that prove the cables were at fault?
.
Or would it need a current flowing through them.
Sadly I can’t plug say an iphone in as its B type of USB. On the Camera end.

My other idea was to use the short 500mm USB cable from rear camera to the battery pack.
Would this be a reasonable test that the USB cables were at fault?

If its the cables then I could change these, however if its the Camera; then I think I am stuffed.
Because if its radiating interference out of the camera, I dont see how I could stop that being picked up by the rear windscreen antennae ? As the camera is stuck on the windscreen.
Any ideas?


Out of interest, what in a camera could cause interference ( its a sort of low pitched repetative ...”wha wha wha” sound).
Do they convert the 5V back to 12v inside the camera?

Also if the intereference “generator” is in the camera, would it then naturally radiate out along the USB cable.?
 
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Submariner1

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I tried the rear Camera powered by the TQKA Battery using the existing 4m leads, and a short 300mm USB Cable (same make).

As soon as the power was turned on (with the button on the battery), the interference started. :(


Not sure what to make of that result. Other than it seems any power to the Camera produces interference, therefore its the Camera! .

Interestingly as I leant towards the original long Cable to undo it, as I touched the cable the interference really dropped.


With the short lead attached to the battery pack, and on even just waving it near the rear windshield, started a little interference.

Very sensitive antennae amplifier?

I also tried using the battery pack and the existing 4m leads, and unplugging the power USB cable at the Camera, this significantly reduced interference.
But even moving the disconnected cable produced some minor interference.

TBH I am pretty much out of ideas on solving this,


- Maybe very well shielded USB cables might reduce it?


- Would those clip on Ferrite Ring things control this, if say I put one near the camera?

I ordered a few from eBay just incase.
 
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daibevan

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Do your dashcams have an internal battery? You could try turning them on with the cables removed. This might confirm if it's the cameras or something else.
 

M80

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As suggested RF interference from the equipment.
The experience I've had is interference from cheapo Chinese USB chargers and also from a mirror mounted dashcam.

My antenna is front screen mounted, but testing USB chargers in rear 12v sockets, even with no load, still affected reception.
Now with any new kit I'll tune to a weak station, easy up here as most are, and see if its reception is affected when applying 12v to it.

Maybe you can sheild, wrap a ferrite loop around, drive with a metal hat on and right hand on that, but I just replace the offending kit.
 
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Submariner1

Submariner1

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Do your dashcams have an internal battery? You could try turning them on with the cables removed. This might confirm if it's the cameras or something else.

Yes they have very tiny batteries.
When you cut the power the interference remains for about 30 seconds, then stops completely.
As it says in the manual, the dashcams will record for 10 seconds after stopping the car .
I assume thats proof its in tne dashcam, i.e. the interference stays as ling as the little batteries have power .
 
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Submariner1

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As suggested RF interference from the equipment.
The experience I've had is interference from cheapo Chinese USB chargers and also from a mirror mounted dashcam.

My antenna is front screen mounted, but testing USB chargers in rear 12v sockets, even with no load, still affected reception.
Now with any new kit I'll tune to a weak station, easy up here as most are, and see if its reception is affecten when applying 12v to it.

Maybe you can sheild, wrap a ferrite loop around, drive with a metal hat on and right hand on that, but I just replace the offending kit.

Totally agree with you.
Sadly I bought a second one, as the video is probably the best I have seen.
As I never listen to the radio I didn't realise this, because on CD there is not interference.


I have ordered a couple of those clip on ferrite ring things, off ebay and will try them on the power to USB and also on the USB cables.

I will then give up.

My investigation was more checking the Amplifier had been repaired properly.

I am ****ed off, as I only turned the radio on because many said, the signs of severe water damage in the Amplifier, was you loose the radio stations names and frequency.

Massive coincidence, whenever my intermittant loss of sound appeared I would check the radio.
Hence the ad hoc results ... in hindsight ... if I checked and the engine was off then radio starion names appeared, but I guess if the engine was rUnning then no names ... sent me off on a wild goose chase! lOL


Luckily I had no water damage, just brake dust in the yellow circle part of the Amp. PCB.under the fan.
946AD567-94F7-495A-BC8D-0C1253187C36.jpeg
Oh well at least the Amp. Is all sorted.

And I can live with the dashcam issue.
 

M80

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If you disconnect all add ons and then try the FM for a reasonable period I would have thought that would test the amp as working correctly, or not.
 


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