Mobile scanner interference

[IzzyEng4 427]

Hola people!

Well I'm at my wits end here and I need some help. I have been getting a lot of electrical interference again though my XLT780 with a Scanner Master remote head. I've done just about everything, including placing a ferrite block on the CAT cable from the base to the head unit, tried changing antenna locations(cowl mount, mag-mount on the roof and a Ham mutli-position mount on my back hatch) and even throwing a choke filter inline with the power and ground wires.

I'm at the point where I think it is my whole set up period. My truck is a '99 Mercury Mountaineer SUV and the the only other added stuff is a Whelen 8 bank power pack for my lights, a MTX amp for my sub-woofer, a Kenwood radio and A Sirius receiver. I do not get any engine noise through the regular radio, Sirius or the sub amp.

Mind you that I've got the electrical interference before the added accessories also with this scanner now and before the remote head was added to the setup. It is definitely engine noise coming through the scanner. I know I can't eliminate all of it but the noise coming though is really effecting the quality of reception. Departments that I have DX from a distance are barley coming in now.

I usually can figure this out but right now I need help and at a loss.

[Ex-2114 7]

Where are your getting the +12 from?? Is it a common distribution block or via an ignition-switched relay? How about the ground?? Is that a common grounding point for other electronics?? If not, are the other electronics grounding within 12" of where the scanner is grounding? Have you tried grounding directly to the battery (as a test only)??

Here's another one for you -- is the scanner mounted in the vehicle?? If so, is the mounting bracket bolted/screwed into the vehicle's steel??

The reason I am asking all of these questions is that back in the day (10 years ago at least) I had a similar problem and the cause was a combination of the common power block and a centralized ground. The ultimate solution was to use a relay for the +12 and a dedicated ground to the battery (fused). The mounting bracket was also a bit of a problem, so I used non-metallic fasteners (can't remember what they're called).

If all else fails, try a Ground Loop Isolator. Radio Shack sells them I think.

[IzzyEng4 427]

I have gone direct to the battery and also through the fuse block, non ignition block, same results with different antenna locations as well since antenna's can pick up noise. The scanner is not mounted to a metal portion of the truck / interior chassis.

Now that you said it, the ground is not to a common grounding as the other electronics, so It could be that right? I'm gonna run anothe scanner in the car with a different power hook up on my next day off and see what happens then.

It'll try what you said also. I usually can figure this out but this time I'm at a loss for this. I never had this problem before with any vehicle.

[Alarmroom 0]

What are you using for an antenna? is a window mount or a perminante mount? SUV are very susipitable to ignition noise especially Ford products. I use a master filter on the hot side of all radios. It sounds alot like you are geeting this thru the antenna lead, also remember alot of problems usually come from the antenna.

[JetPhoto 626]

the only other added stuff is a Whelen 8 bank power pack for my lights, a MTX amp for my sub-woofer, a Kenwood radio and A Sirius receiver.  I do not get any engine noise through the regular radio, Sirius or the sub amp.

I usually can figure this out but right now I need help and at a loss.

←

Get rid of the Sirius radio, that thing must draw alot!

JK...

[Skooter92 7]

You could also try an isolation filter (like a Kenwood KLF-2) instead of a plain choke inline between the scanner and the battery. Try shielded CAT-5 instead of the supplied cable as well.