Tuning is NOT the issue. You need to cure the problem at the source, and that source is NOT inside the radio. The reason you hear it more on 11m is simply because the radio's receiving circuits are peaked in that range and sensitivity is better.
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Engine noise
- Thread starter nfsus
- Start date
Tuning is NOT the issue. You need to cure the problem at the source, and that source is NOT inside the radio. The reason you hear it more on 11m is simply because the radio's receiving circuits are peaked in that range and sensitivity is better.
Yeah CK is right about that. Also be advised RFI Radio Frequency Interference has frequencies that are louder than other frequencies. So some frequencies will have louder stronger noise levels, and some frequencies little or no interference levels. Measuring the local vehicle area as compared to frequency bands with portable all band receiver will indicate this.
Jay in the grate Mojave Desert
Jay in the grate Mojave Desert
id bond doors,body,hood,trunk,muffler? yes muffler to chassis then to battery ground point. id make sure your getting direct current on the + side not using the wiring harness in your vehicle. and USE BRAIDED COPPER WIRE
Yes thats also a good call grounding all the body parts. One the best things I did in my Ford truck was to connect the fire wall to the hood and front fenders. Then ground the exhaust pipes in two different locations on the pipes to the frame and body.
Jay in the Grate Mojave Desert
Jay in the Grate Mojave Desert
Yall gonna love this. I changed everything. Coax, antenna, mount, location and radio. Changed to a kenwood 120s mobile Hf rig. Tried beads on the coax assuming common mode currents, helped some maybe. The radio is ssb and cw only. In ssb mode it shows full key wattage like a carrier. It works fine in the house. With a screwdriver antenna, when resonance is reached it kills the truck engine. So somewhere im getting rf I assume. I'm telling you I'm gonna pull out my nose hairs.
Update.
Kenwood 120s radio shutting off truck resolved.
Service bulletin from 1980 shows how a failure would key the pa at full power throwing standing wave on the radio. Was shooting 160w over the shield to the frame of the truck. It only did it on 21mhz and up. Corrected that issue, carrier on ssb is now gone, audio cleared up, rf on the truck is gone. Still have engine noise so I'm still hunting that.
So theres that
Kenwood 120s radio shutting off truck resolved.
Service bulletin from 1980 shows how a failure would key the pa at full power throwing standing wave on the radio. Was shooting 160w over the shield to the frame of the truck. It only did it on 21mhz and up. Corrected that issue, carrier on ssb is now gone, audio cleared up, rf on the truck is gone. Still have engine noise so I'm still hunting that.
So theres that
Normally I would avoid long distance trouble shooting but you are describing a tough problem where you have done all the stuff.
Is the length of anything resonant including the ground strap? My suggestion would be a choke balun, like the beads that you tried, at the antenna.
All About the 1:1 Current/Choke Balun
How a 1:1 Guanella-Balun (Current-Balun) Operates By Jerry Sodus, KM3K In the spirit of the hobby, I pass along what I have learned and don’t profess to know all the answers. 1. The primary reason for this work is to explain how a particular Transmission-Line-Transformer (TLT) known as a 1:1...
Its hard to help out when your not there. But as said before the noise source is the place to start. I take it you have ignition noise. Are the spark plugs, wires, rotor cap, and rotor old and wore out, needing replacement????? I have seen old spark wires arc all over the place as the insulation cracks open, at the dark of night.
Jay in the Grate Mojave Desert
Jay in the Grate Mojave Desert
I had a Ford Explore 1994. I had a constant whine. I had a local mechanic put the caps on the fuel pump power wires and that was the fix, as the fuel pump was the source.. Just want to mention , in case not tried yet
I had a 2010 Ranger that required putting chokes on the fuel pump wires at the fuel tank to stop noise.
They were famous for that.
73
Jeff
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