Radio Interference

[Intrakota]

I have 2 PDR100 recorders installed in 2 ordinary cars. The VHF radio's installed in the car's work fine untill you turn on the PDR100 instantly you loose or have great difficulty in picking up signals that were previously available, in one vehicle the recorder is on the front parcel shelf about 18 to 24" from the radio, on the other vehicle the recorder is located in the boot with a SS1000 processor interestingly the processor does not cause any interference to the radio at all, just the PDR100. Our previous 2 recorders were made by Archos and gave no interference problems, this situation with the PDR100 is somewhat dissapointing considering how much this gear costs in comparison, is there a work around for this problem as I belive im not the only one. :mad::mad::mad:

[BroussalM]

Hi

For your problem, I think the reflection is more on the good working of the radio than the PDR.
Understand me, The PDR work in all set up, not the radio.
Just a detail, prefer real 12v for the power of the PDR than AAA. When PDR change 4x1.2v to make 12v it could make some interferences ( realy not sure but... ).

So in first : Get off the AAA and power the PDR with real 12v and try.
If it dont work :mad:


You must work on the power of the radio.

Get a special power wire for your Radio. Realy independant about anything and coming directly from the battery.

Adjust the way of the wires to pass as far as you can from the power wire of the PDR, the cam and the global power of the car.

Hope it's help you, you're going to forget very fast the poor quality of your old "Archos" on your TV after that!:D:D:D

Michel Broussal

[Intrakota]

Im just wondering if this unit should carry the European CE type approval mark of conformity, electromagnetic conformity EMC being one area for testing, especially if it is being used onboard aircraft. My previous Archos recorder carried the CE mark and never caused a problem when used in the same vehicle right next to the car radio.

http://www.conformance.co.uk/directives/ce_standards.php

[Intrakota]

So am I the only one using these recorders in road vehicles, I now have two units with G-force and two HQ cameras, everything works fine but, the interference problem persists. I have attached several ferrite core's to the power cable from the car's power point and shortened its length to a minumum, this has had an effect on the level of airborne interference being produced and when the boot lid is closed things seem to improve yet again, the Faraday cage effect I suppose. Maybe the power cable is acting like an antenna, next step is to obtain some good quality shielded power cable and try that.

No comment from Chasecam themselves on this matter I see. :(:confused:

[RandallNoll]

Intrakota,

I hadn't replied because Michael seemed to be offering sound advice for troubleshooting. It sounds like you've made headway and your next step (shielded cable) is probably where I would have gone/advised.

Each setup is different. Most of the cases we've seen are where vehicles have caused interference with the PDR--sometimes to the point that it shuts off, but this is usually on a race car with a very powerful ignition. I personally haven't had any interference with a PDR or SS1000 in my road car, though I have heard static in my radio when my cell phone rings.

In cases like yours and in the one I describe above, we usually go down the path you're going. Moving things relative to eachother and shielding wires seems to have the greatest impact.

Hope this helps.

[RandyChase]

Plus we are working on an engineering improvement, but it takes time.

[Intrakota]

Any news on this engineering improvement to eliminate noise to O.E. VHF car radio's.

[Mark1567]

I would use the isolation methods regarding the power cables to the radio and the power and video cables to the PDR. Also, it is always a good idea when dealing with RF mobile installs to use correct RF grounding techniques. The copper tinned i" braid and a good rf conducting compound when making connection to radio box to car chassis, and same with the PRD box and make the strap as short as possible. Also, you should be installing a #43 ferrite RF choke on both ends of each cable.
http://www.radioworks.com/ has these in kits as well as much more useful information of proper RF grounding techniques. Stray RF bouncing and reflecting inside a vehicle chassis is very troublesome to say the least. Also, the type antenna used on the vehicle, rf grounding, ground plane etc are of equal importance. If you are using a 1/4 wavelength whip antenna say mounted on the roof, how far is it in terms of wave length form the PDR and try to keep it in odd multiples. A friend of mine had receive problems with his VHF radio from the pits within line of sight and it turned out that he had a 1/4WL antenna NMO mount on the roof but the roof was fiberglass. Since the antenna was missing its other half wave, the radiated pattern, same in transmit and receive, was severely distorted thus his signal to distortion ratio was very weak. He cut out a round approx. 24' circle of aluminum and mounted it inside under the antenna , where before even his ground of the NMO mount did not even have DC continuity to the car body or chassis. The added ground plane did improve his situation and the other option would be to use a base loaded 1/2 wl no ground plane type antenna. I've seen several road race cars with their VHF or UHF 1/4wl antenna mounted right on the dash in front of their video camera. Wonder what the video looks like when the radio is transmitting? RF interference works the same both ways no matter the power difference from Xmit to receive because the path distance is the same.

Mark

[Intrakota]

So a year later and Chasecam are still working on a solution to the radio interference problem then, obviously not.

[RandyChase]

Our new recorders are being released for production this coming week. We tested them for EMI this last week and they performed very well. They should solve the issue.

Sorry we can't do more than that, we have been flat out in development for 2 years on this, as fast as we can work.