engine noise coming through radio?

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MichaelT0101
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engine noise coming through radio?

Post by MichaelT0101 »

I have a 03 nissan frontier kingcab I have my power wired straight to battery I have tried a bunch of inline filters nothing seems to stop the motor noise coming in is their anyone who could point me in the right direction. info on noise, engine off no noise engine at idle low noise the faster the engine goes the louder the noise any thoughts how to make it go away. The filters I have used where from radio shack , pilot truck stop, and flying J.
MichaelT0101
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altinator whine

Post by MichaelT0101 »

I found out it is the altinator does anyone no how to get rid of altinator whine?
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marveylus22
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Post by marveylus22 »

Make sure you've completely installed your CB and the antenna is grounded properly. Check the amount of noise with and without the antenna connected. If the noise is greater when the antenna is connected, the source is probably the ignition system. If the noise remains unchanged after disconnecting the antenna, the source is probably in the CB's power supply.
- For ignition noise, there are several parts of the vehicle that can act like RF noise transmitters if not properly grounded. Check (and connect to ground on the chassis/frame, if necessary) the engine block, hood, muffler, and exhaust pipe.
- Ignition noise can be further reduced by installing "magnetic suppression" spark plug cables. (These are significantly more expensive than normal spark plug cables.)
- For power supply noise, check if you have a capacitor attached to your ignition coil, alternator, electric fuel pump (especially on late model Fords) and distributor. These can act as filters right at the source of the noise.
- Ensure that your antenna feedline and power lines are as far as possible from any of the noise sources mentioned above, especially the engine block.
- A shielded power cable can help as well. Make sure it is of sufficient gauge to handle your radio's power consumption and that the shielding has a good, strong connection to ground on the vehicle chassis or frame.
- Electronics stores such as Radio Shack sell low-cost power filters for noise-reduction purposes. But remember, you get what you pay for. Most comments on this newsgroup are that they are not as effective as the other measures above.

Of course, the best performance can be obtained from a more expensive radio with better noise suppression circuits. These measures, however, will improve the engine noise levels for nearly any mobile radio.
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Animal
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Post by Animal »

As probably stated in the post above (but I couldn't be arsed reading it!) mobile interference is either picked-up via your antenna (radiated) or via your power leads (conducted) - so before you start looking for remedies you need to establish which of the two it is.

Plug a dummy load into the ant socket & if the noise is still there it's being conducted along your power leads into the rig.

Also, you don't say whether your antenna is a mag mounted type or grounded directly to the vehicle bodywork - this makes a big difference as mag mounts are only capacitively coupled to the car (sorry, automobile!) & therefore there is no direct metal to metal contact (poor grounding) & are more prone to interference.

Sounds to me like high-voltage ignition discharge from your spark plugs.

Good luck.

ATB

Animal :twisted:
You're 5 & 9 - what's your QRZ again???
frogman296
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Post by frogman296 »

ground ground ground
dizgolfer
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Post by dizgolfer »

Just a couple things I can add from trial and error on my mobile install. Everything previously mentioned is good and these two things really worked for me. I ran a 6 gauge wire from one of my alternator mounting bolts to the frame. For a power cable I took a some old rg8 with a stranded conductor. I connected the center to the positive terminal of my battery for the power. I connected the shield to the negative terminal of my battery. The important part is not to connect the shield to the ground on your radio. Just connect the center to your radio for the power and connect your negative lead off the back of your radio to the nearest good ground. The shield of the coax is just connected to the negative battery post and the other end to nothing.
RedEye
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Post by RedEye »

Alternator whine (if proper grounding isn't the problem) is usually due to a failing or bad zenor diode in the alternator itself, allowing a/c cuurent feedback. If it gets really bad, it can be the mysterious cause for a battery draining down in the car. A quick (and non scientific) test is to place a metal screwdriver (WITH THE ENGINE AND KEY OFF) near the rear bearing housing on the alternator. If a magnetic force pulls the screwdriver to the alternator, it has a bad diode allowing the stator to stay powered. The reason is the diodes are allowing power to flow backwards from the output cable on the alternator back to the stator.

You can also isolate the output cable from the cars wiring harness. Many car makers don't run the output cable from the alternator directly to the battery, instead it goes to a junction point where the car elctrical circuit is attached. By removing the factory output cable and making a direct connection to the battery will also eliminate alt whine. Be sure to use a heavy gauge wire!
rrtddaa64
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CB Engine Noise

Post by rrtddaa64 »

Make sure you got the Risistor type Spark Plugs. That's what use to help me.
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