Ham Radio Frequency Interference

For my Ham Radio Operators out there. K5ZED here, looking for help with an issue that has plagued me for a few years.

Issue:

I have a 2meter/70cm D-Star radio (Icom ID-5100A) with a Comet CA-2X4SR Mobile VHF/UHF Vertical Antennas CA-2X4SRNMO. I have mounted the antenna on both the driver and passenger side of the Jeep in the front on the hood using a Comet RS-720 Mobile Antenna Adjustable Lip Mounts RS-720NMO. I am having some terrible interference on certain frequencies; notably the local repeater I am on daily, 146.7900 and others. I used to have a lower quality antenna and thought that the issue was that...hence the reason for the upgrade. I have upgraded everything, the antenna, radio, feedline, mounting equipment and I am pretty sure its due to some rogue wireless sensor on the Jeep. I know this now, because I took my hand held radio with a rubber ducky, inside the jeep with the exact same issues.

Questions:

Has anyone else run into an issue like this?
Does anyone know what sensors or devices in the Jeep that could be causing the interference?
I have turned off the TPMS via Superchips Traildash hoping that was the cause, but that didn't no anything.

2012 Jeep JK Wrangler 4 Door

Following this one. I also have a 5100 that I plan to install in my Jeep.

A few suggestions and questions:
1) how are you powering the radio? Directly from the battery and with what cable gage?
2) where/how are you routing the power and antenna cables?
3) how's the overall grounding? Are all doors/hood/gate properly grounded?
4) is the radio causing the interference or suffering the interference? It was not very clear to me.

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And 73 de KE7GON!

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I haven't installed a ham in my rig. when I installed the CB, I ran the cabling to close to the main harness and got a lot of interference , when the jeep was running.


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Sahara_Maverick said:

Following this one. I also have a 5100 that I plan to install in my Jeep.

A few suggestions and questions:
1) how are you powering the radio? Directly from the battery and with what cable gage?
2) where/how are you routing the power and antenna cables?
3) how's the overall grounding? Are all doors/hood/gate properly grounded?
4) is the radio causing the interference or suffering the interference? It was not very clear to me.

Sent from my SAMSUNG-SM-G891A using WAYALIFE mobile app

Click to expand...

1. I have a power brick for both the positive and negative terminals that I ran for other accessories. Not sure of the gage off hand but probably 4 or 6 gage because of what it is used for.
2. Running through the firewall on different sides of the vehicle
3. I don't have any actual grounding for the antenna. The antenna is on a mounting bracket but its not grounded too anything. I'm not an expert with antennas, but I thought I didn't need to ground it to anything. Additionally, the old antenna I did have was grounded to the Jeep. I tested continuity everywhere with good results. This new antenna and mount doesn't have any of that grounding. (see pictures in original post)

4. Sorry if I wasn't clear. The radio is not causing the interference but rather something in and around the Jeep is causing the interference. When I take my handy talky with a rubber ducky and sit in the driver seat and move the radio around the inside of the vehicle, while turned to 146.7900, I'm experiencing the same interference that my mobile rig is having. When I get out of the Jeep and walk away from it a very short distance (couple of feet), the interference dies out. Also, if I wait in the Jeep, after a short time (usually about a minute) all of the electronics in the Jeep shut off and the interference goes away. That right there convinces me there is something in the Jeep causing this.

Additionally, the interference is only on the incoming. I do not get any reports of transmitting issues and in fact on 25 watts I'm hitting the repeater quite well. When someone else transmits, it comes through very clear. It only seems to be when the radio is idle and listening. I have had to crank my squelch to max and even that sometimes doesn't work.

Lastly, I did test having the feed line not run by anything (hooked up to my handy talky) away from the jeep but the antenna mounted on the Jeep and same bad results. I am convinced that the issue lies in some electronic sensor or device inside the Jeep. With the several different configurations I have tried, the common denominator remains that.


About the 5100A

I like the radio; the menus are great and its easy to work for the most part. My one and only gripe right now is at night it is too dang bright. Even with the display lights set as dim as it goes. In the Jeep I am limited on mounting so its on the window to the left of me, right in my eye sight. I still own an Icom ID-880h and I always used the amber shade which was way easier on the eyes. I'm thinking of keeping the 5100 in my Ham shack and buying the upgraded version of the 880h which is the ID-4100A. It has a very similar menu structure as the 5100A but it has the shade color options.

What I have found to be the biggest cause of white noise on my rig was the fuel pump. Prob cuz everything is plastic. Tried a couple of ferrite chokes, a lot of trouble with very little help


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ChuckMRN said:

What I have found to be the biggest cause of white noise on my rig was the fuel pump. Prob cuz everything is plastic. Tried a couple of ferrite chokes, a lot of trouble with very little help


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Click to expand...

Any chokes you recommend. The ones I'm using I think are pretty cheap and not working very well. Then again, I may not be doing it right. If you have a picture of your set up, could you post that?


Edit: I added a length of cable and two chokes with several wraps on the feedline close to the radio end and no change at all. It might have made it worse even. I'm at a loss at what to do.

I used the 1" rings and wrapped all the way around with one on both Pos and Neg wires. Then used some heat shrink to cover it and taped it up. Did all this with the tank dropped when I welded in the long arm mounts. No way to really take a Pic now. The chokes are most effective when closest to the noise source. So they say. I still have some noise, but not as bad as it was on my 2011 with out this mess.

Cheers, KK6TBX

zeddjb said:

Any chokes you recommend. The ones I'm using I think are pretty cheap and not working very well. Then again, I may not be doing it right. If you have a picture of your set up, could you post that?


Edit: I added a length of cable and two chokes with several wraps on the feedline close to the radio end and no change at all. It might have made it worse even. I'm at a loss at what to do.

Click to expand...

Did you ever get this issue resolved?

I just installed a Yaesu Ftm-100dr in my 2015 JKU and I am having the same problem on the exact same frequency as you. I have ran the power lines and antenna different directions and still have the problem.

Randy B
K3RAB