2003 ranger full quieting noise

Hello everybody. I have a 2003 ranger and am having rfi issues with my ic-706mkiig on HF. The sound dies as soon as I stall the engine and of course when the ignition is off. I have the radio hooked directly up to the battery and grounded to the frame. The noise is not the typical spark gap generator noise (lol!) but is rather constant in intensity. I have tried 43 mix beads on the ignition wires and on the power leads. The noise is radiated, as it disappears as soon as I disconnect the antenna. Any ideas or personal experience? Thanks!

73 de KD5IKU

 

[Choprdoc]

I had almost the same noise. Found out using a sniffer that is was coming from the alternator. Installed some caps on the alt. Took a little time to find the right values though

 

[Ray Hutchinson]

Noise

KD5IKU,

Have you read the "stickies" : articles at the top of the forum dealing with noise. frequently the fuel pump is a source in our vehicles. The power leads to the pump act as a radiating antenna. Check out the above posts.

 

[kd5iku]

In what fashion did you hook the caps up? Also, do you remember what values you ended up using?

 

[kd5iku]

checked

I have read the sticky posts and am aware of the problems with the fuel pump. If I am not mistaken, (Which I very well could be,) I thought the fuel pump noise came a few seconds after starting the truck, not immediately. I will experiment this weekend and try putting filtering on it just in case. As for the person with the alternator problem, do you remember what value of caps you used? Thanks!

73 DE KD5IKU

 

[Sandy]

Hey,

Have you tried letting the engine run while the coax is disconnected ?

Ltr

 

[kd5iku]

When the coax is disconnected, and the engine runs, for any length of time, there is no noise. It is most certainly radiated.

KD5IKU

 

[Sandy]

When the coax is disconnected, and the engine runs, for any length of time, there is no noise. It is most certainly radiated.

KD5IKU

Where is your antenna mounted ?

What type of antenna are you using ?

ltr

 

[Ray Hutchinson]

KD6IKU

One other troubleshooting technique to see if your fuel pump is the noise source: Find and pull the fuel pump relay on the power management panel with the engine running, but be prepared to plug it in as soon as the engine stumbles, 3-5 secs typically. Note if the noise goes away with the ralay out. If it does, then your problem is the pump, if not, you'll need to look elsewhere. Did you see the tip about using a 10' or so piece of coax, PL259 on one end, strip away 5-6" of the shield on the other leaving the center conductor exposed. This makes a "sniffer" which you plug into the ant. input on the radio, and move the open end around the vehicle looking for the loudest noise level,
hence the culprit nearby. BTW, some folks also have had noise problems generated by the vehicle computer.

Hope this is a help
best 73