Need a CB guru

[Knightinraggedarmor]

So I got my new CB hooked up, a galaxy DX929 but I'm having an issue with interference/static. I can't turn the rf gain up much before the blaring static comes in and I'm getting a whine that matches engine rpms. Rpm whine is coming from coaxial and not the power side because it goes away when the coax is unplugged. Radio is peaked and tuned pushing about 30 watts, 18 ft of rg8x coax run through plastic cap in cab floor through bed drain to antenna mounted to toolbox. Antenna is a 4 ft firestik tuned to about 1.6 swr across the board. Where should I start looking for my problem with the rpm whine?

 

[MidwestJ]

WAG here but what about a noise blanker?


That was one of the study exam questions for my technician level amateur radio license.

 

[AFMoulton]

That’s the only way to eliminate the noise. Been hooking up Amateur radios in my vehicles for 15 years. Easy cheap way to make it smooth.

For 12-Volt Noise Audio Filter Kills Hum Engine Sound Wine Remover 12V Dc Car Use https://www.amazon.com/dp/B00XKV114K/ref=cm_sw_r_cp_api_O6lGBbW1PE5NJ


2018 2500 6.4 4x4 4.10 Amsoil SS 0w-40, Softopper
Black Rhino Armory 18x9 +12mm
Cooper Stt MAXX LT295/70R18

2016 Durango 5.7 AWD 3.07 Amsoil SS 5W-30
1996 Nissan Altima 2.4 Amsoil SS 5W-30

 

[17CrewCab1500]

Is your coax crossing itself, coiled up anywhere or crossing or parallel to any power cables?

 

[Knightinraggedarmor]

Excess coax is coiled up under my seat

 

[Knightinraggedarmor]

My main question is the 5.7 motor notorious for generating RFI? And if so what's the best way to deal with it?

 

[retep]

Knightinraggedarmor

I had an amateur radio in a different car with a similar problem. A quick fix would be to take some wire, the same size as your power wire or bigger (14 AWG) and wrap it neatly around a 3 or 4 inch nail (try it with 10 - 20 ft). Tape it so it doesn't unravel. Put it in line to the 12v + wire. It will draw more power because of the induced emf but will allow you to determine if the noise goes away. It may pop a fuse as it does draw more current. People on the receive side of your transmission will hear the noise as well.

Is your 12v coming straight off the battery and is it fused??

If that works then try getting a ferrite core like this one: (random search showed these. You may find others as well for a better price)
https://www.amazon.com/Skylety-Pack...8907&sr=1-2-spons&keywords=ferrite+core&psc=1.

or this style

https://www.amazon.com/eBoot-Pieces...pID=51PRPk10wiL&preST=_SX342_QL70_&dpSrc=srch

you can add more than one if you need to. Put them on the 12v+ line or both doesn't matter

Also should ensure you have a good ground.

That should clear up your noise. If you have access to a oscilloscope you can watch the 12v line and see if the noise gets better or worse with things you try.