Inverter causing noise

[bigwoody]

This is going to be long winded, please stick with me. I recently changed trucks. The only difference is that my old truck was a single cab and my new one is extended cab. On my old truck I have a inverter behind the seat with power coming from the battery, and the neg grounding on the tranny. With that setup I didn't have any problems with my Cobra 29, and it was picking up its power and ground from the power supplying the inverter.

In my new truck I ran the power the same way and grounded my neg to the frame. I started noticing that when the inverter was turned on I would receive a lot of noise like if the squelch was turned all the way down and the meter was pegged. I thought that the inverter might have been generating noise when it was turned. I moved the power for my radio to the other battery and terminated the pos and neg straight to the battery isolating the radio and inverters power supply, but I am still getting the noise when I turn on the inverter. Can I install some kind of filter to kill this noise? What options do I have. The only way I can kill the distortion is to turn back the RF gain about 75%.

[bigwoody]

Sorry,
I forgot to add that now I have a Cobra 200 and a Galaxy 95t2 on the way. I don't want to damage the 95t2, and I would like to get full receive if possible from the radio.

[Falkon MX-5]

So, the inverter is not for the radio right? That wouldn't make much since since those mobiles run on battery. The inverter powers other things but causes noise? I had a similar issue. I had an inverter powering a laptop that would play music in the car, but the noise was terrible. Try running a wire from the case of the inverter to the truck chassis, and a wire from the chassis of the radio to the car body. It can't hurt anything.

[bigwoody]

Thanks for your input. The inverter is for my laptop. I am going to try some more grounding today.

[bigwoody]

I have grounded everything, and I still have the noise when I turn on my power inverter. I removed the coax from my radio and turn on the inverter the noise goes away. I moved the coax to the opposite side of the truck and reconnect it to the radio and turn on the inverter and the noise comes back. What do I do??

[Falkon MX-5]

It sounds like either the noise is getting picked up by the coax or it's getting picked up where the antenna mount grounds to the chassis. I don't know why inverters are so noisy.

[bigwoody]

should I try another coax, or ground the antenna somewhere Else? This is on a ford f350 with a service bed on it.

[Falkon MX-5]

Something it could be is the inverter throwing noise back on the power wires. The only way you can really fix that is with some big common mode chokes on the power lines. You can get ones that clip on like you see on cables to your computer monitor and mouse. Does the noise whine when you accelerate?

Also, is the noise only there when the inverter is on?

[bigwoody]

It isn't a whine, and it doesn't change when I accelerate. when the inverter is on the the meter jumps to the right and the noise sounds like the static noise when the squelch is turn all the way down. If I turn the RF gain down to about 25% is goes away when the inverter is on. If I turn the inverter off it goes away completely.

[Phaze91460]

Radio Active can probibly tell you in more detail than I can but here goes.

A power inverter uses a spicific wave form to change to 12v to 110v AC and that wave form causes noise in audio circuits.

I have had the same problem with my laptop. I have a alpine head unit that has 2 aux inputs. I use one for my laptop so I can watch movies etc. Problem was that I couldnt have the inverter powering up the laptop or there was a hell of a noise. I actualy fried my first head unit because of that. I ended up just using the laptop batters and all was well till the battery died. Now I use a laptop power supply that plugges into the cig lighter for power and no problem.

I cannot use my power inverter at all with the CB on or there is a high ammount of background noise and sometimes a steady surging. My power supply is a 1000 watt unit.

I have all the grounding in the world and have changed locations etc. to no effect. Finaly some friends in the electronics field told me about the wave form problem used.

All I can say is that if it worked in one truck and not in the other, be glad it worked in the first one !

[Falkon MX-5]

that's pretty much what I've gathered. They assume you're going to use the thing for powering a device where noise doesn't matter

[jessejamesdallas]

I also have a power inverter in my work van. Its a 3000amp inverter, and when it's on, there is no way to use the radio, without hearing tons of noise. (least when its running something. if just turned on, but not powering anything at the time, then its OK)

There are some inverters that use a different wave of current, but their expenceive. I think however, just about all those things are going to cause some noise in CB...Just some more than others...

[bigwoody]

Has any one tried shielding the inverter with foil to stop the RF noise? Mine creates feed back when I turn it on without a load. I tried a 75w cigarette plug style and the noise wasn't as bad but I still picked up a little when the inverter would cycle. I also came across as accelerator noise. on the little inverter, but not the big one. 1750 watts on the big inverter.