Liberty CRD Diesel '06: Interference with 2m radio transmissions

With a Yaesu VX-5 powered from a Radio Shack car cord attached to the
console cigar lighter socket, I get rapidly repeating noise likened by
others to spark plug noise; but, no spark plugs on a diesel. Removing
the card cord and transmitting on battery eliminates the problem.

I'm about to switch from the VX-5 HT to a Kenwood TM-V7A; how may I
avoid this problem when installing the mobile transceiver.


Thank you in advance for your on-topic suggestions.

73s & best regards,

K7AAY

 

Fuel injectors are the most likely source of the noise.

First, use a direct connection to the battery terminals. Second, twist the
connecting wires 2 or 3 twists per foot from the battery to your radio. Third,
get a GOOD chassis ground connection for the radio.

If noise persists talk with the CRD service techs regarding slightly slowing
down the rise time of the fuel injectors or adding a suppression diode across
the fuel injector coils [it is unlikely you will get any support in this area,
but worth a try]

 

If you contact DC, they might send you the booklet on installing a
transmitter into the vehicle. They get very specific on where the power
and grounds can be run as well as the antenna wire.

On GM's for instance, you have to have a 10 ga. dedicated fused power
and ground line to the battery run far away from any vehicle harnesses
to avoid voiding the vehicle warranty. Transmitters can interfere with
things like the ABS and transmission modules, like some TJ's will go
into neutral when the transmitter is keyed up, and any other electronic
part.

Here is a link to GM's instructions, I haven't found any online for
Jeeps:
http://service.gm.com/techlineinfo/radio.html

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

 

<snip>

Thank you for your on-topic reply!

I do have the equivalent for a 2006 Charger Police Edition, which may
be downloaded from the very last link at http://www.503bartley.com and
will look for a similar "outfitter's guide" for the Liberty.

 

Excellent advice. I would add: fuse both hot & ground for good measure at
the battery ends of the connections. You could also loop the power cord a
couple of times and put a ferrite bead on the power leads.

Always run heavier wire than you think you'll need. It reduces loss and
someday you might want to put out more wattage.

If it's a temporary set-up, use one of those gel-cell booster batteried to
power your radio.

73s!

 

Hi...

With all due respect, don't even think about fusing ground.

Take care.

Ken

 

Great! Now comes the interminably long thread where everyone argues
this Old Rule once again -- without anyone changing their mind -- and
with each post starting "With all due respect ..." containing little.

*plonk* the thread

 

Fusing the ground is recommended and required to do it properly on a
GM. If the vehicle loses it's body or engine ground strap connection
for any reason (like corrosion for one) the starter or alternator or
body/lights, etc. can use the radio as a ground. This usually lets the
smoke out of the unit big time.

http://service.gm.com/techlineinfo/radio.html

I have installed hundreds of transmitters in one contract I had and when
they came back in for repairs over the years, on about 98% of power
short issues either vehicle related or transmitter system related had
the negative fuse blown before the positive one. There were lots of
cases of blown fuses due to ratty vehicle grounds also.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

 

Well, I have a '99 TJ with a 40 watt police radio wired from the battery.
Noooo problems in 2 years. Automatic, air, GPS etc also.

When I transmit the GPS loses it's location however.

 

a ground from the battery is the best way to eliminate that type of noise