Radio Frequency Interference (RFI) fix needed

[Sailing Santa]

I’ve got some crazy radio interference happening while the accelerator pedal is being pressed on my ‘16 Cummins. The radio is a high dollar rig (Icom IC7100) and I’ve installed it using filters ferrites on both antenna coax and power input, yet the RFI persists. I’m quite sure that it’s not an isolated problem and am wondering if RAM has a kit to take care of it. Many other manufacturers have kits to prevent/reduce RFI for law enforcement or fire department radios. Does Ram?

 

[Mister Luck]

I’ve got some crazy radio interference happening while the accelerator pedal is being pressed on my ‘16 Cummins. The radio is a high dollar rig (Icom IC7100) and I’ve installed it using filters ferrites on both antenna coax and power input, yet the RFI persists. I’m quite sure that it’s not an isolated problem and am wondering if RAM has a kit to take care of it. Many other manufacturers have kits to prevent/reduce RFI for law enforcement or fire department radios. Does Ram?

I do not know if a RAM parts department would have a kit. I believe most of the electronics for mobile use are installed by specialists.
Here is a link to a forum that addresses RFI in mobile electronics installations

Suppressing RFI without the use of a ferrite choke?

I'm in the middle of a mobile VHF/UHF install and I want to take a few extra steps to help eliminate/reduce transmitted and received RFI. I've...

forums.qrz.com

Here is a link to products for possible solutions

Portable and Mobile Radio RFI Solutions - Mobile Station RFI Kits - Palomar Engineers®

Portable operation is fun but also brings challenges to the radio operator concerning receiver “noise” levels, RF interference from adjacent sources including close by transmitting stations, and RFI from portable generators. A typical scenario and some suggested Palomar product solutions are...

palomar-engineers.com

 

[BossHogg]

Can you be more descriptive on the type of interference? Is the transmitter causing vehicle issues or is the vehicle causing receiver issues? What band, what mode, where did you locate the antenna(s).

I've got a 2015 3500 Cummins with hams radios installed, no issues I've detected.

 

[Sailing Santa]

I’ve got the 7100 led to a lil’ Tarheel 2 on the bedrail using a grounded Breedlove mount. I’ve also got a 5100 installed as well going to a 5/8th wave on the other bedrail also on a Breedlove mount. Overkill, but it works well for me. 20 meters seems to be the most affected with the static but it’s there on all bands. Really killing copying any DX. Scratching my head. I’ve got the body panels bonded to frame and engine. It sounds most powerful when the acceleration pedal is pressed. So - is it the injector pump or that computer controlled pedal?
When I worked installing Motorola for the police departments, there were notices on how to deal with RFI. Granted, these were Crown Vics and Broncos but there has to be something figured out somewhere. I’ve got ferrite everywhere and a common mode choke too. Only thing I have not tried is wrapping foil around in the engine compartment.

 

[Sailing Santa]

I do not know if a RAM parts department would have a kit. I believe most of the electronics for mobile use are installed by specialists.
Here is a link to a forum that addresses RFI in mobile electronics installations

Suppressing RFI without the use of a ferrite choke?

I'm in the middle of a mobile VHF/UHF install and I want to take a few extra steps to help eliminate/reduce transmitted and received RFI. I've...

forums.qrz.com

Here is a link to products for possible solutions

Portable and Mobile Radio RFI Solutions - Mobile Station RFI Kits - Palomar Engineers®

Portable operation is fun but also brings challenges to the radio operator concerning receiver “noise” levels, RF interference from adjacent sources including close by transmitting stations, and RFI from portable generators. A typical scenario and some suggested Palomar product solutions are...

palomar-engineers.com

I’m already way past doing this stuff.

 

[Sailing Santa]

Can you be more descriptive on the type of interference? Is the transmitter causing vehicle issues or is the vehicle causing receiver issues? What band, what mode, where did you locate the antenna(s).

I've got a 2015 3500 Cummins with hams radios installed, no issues I've detected.

Oh. Should have said. This is almost like an ignition static, but being the Cummins it can’t be ignition.

 

[Mister Luck]

Have you tried using a spectrum analyzer to hunt down the RFI without turning on the radio.?

It would probably be helpful if you could tell us ( all ) the things you think it can’t be.

 

[BossHogg]

Oh. Should have said. This is almost like an ignition static, but being the Cummins it can’t be ignition.

You just are not providing enough information for anything more than a general answer.

You get the interference when depressing the accelerator pedal and it sounds like ignition static which can not come from the engine. If it sounds like static then it can not be a harmonic from any of the computers. Again, mode, band, and is the static noise on all bands, some bands or just one band?

 

[Mister Luck]

You just are not providing enough information for anything more than a general answer.

You get the interference when depressing the accelerator pedal and it sounds like ignition static which can not come from the engine. If it sounds like static then it can not be a harmonic from any of the computers. Again, mode, band, and is the static noise on all bands, some bands or just one band?

It could be the radio itself, It could be the alternator stator, Basics are looking for the interference with a hand held device.

I’ve been studying for my tech license in HAM since just before the pandemic, most of the FD’s provided license testing sites but now you need to make an appointment and if there are enough people hopefully by the end of the month maybe next month…

 

[Sailing Santa]

Good luck on the test. Glad to have another brother in radio.

 

[Mister Luck]

Good luck on the test. Glad to have another brother in radio.

Its spring time isn’t this the time of year for the radio anomalies .. ?I mean in general not your radio problem

 

[BossHogg]

Its spring time isn’t this the time of year for the radio anomalies .. ?I mean in general not your radio problem

The noise floor comes and goes and I don't know what causes it for me. I live very rurally so man-made typically isn't the source. Most of the time my noise floor is in the weeds but I've seen it as high as s5 on 80 meters and S3 on 20 meters.

Spring and more so summer bring atmospheric ducting, enjoyable on 50 meters and up. The sun brings skip and we are in what looks like the beginning of a good sunspot cycle.

Do a search in your area for ham radio clubs. They typically offer VE testing. COVID didn't slow that down in my area (SE Michigan). If that doesn't pan out, get to the ARRL.org site, you will find testing site information there. Good luck, n8zcc

 

[BossHogg]

I’ve got the 7100 led to a lil’ Tarheel 2 on the bedrail using a grounded Breedlove mount. I’ve also got a 5100 installed as well going to a 5/8th wave on the other bedrail also on a Breedlove mount. Overkill, but it works well for me. 20 meters seems to be the most affected with the static but it’s there on all bands. Really killing copying any DX. Scratching my head. I’ve got the body panels bonded to frame and engine. It sounds most powerful when the acceleration pedal is pressed. So - is it the injector pump or that computer controlled pedal?
When I worked installing Motorola for the police departments, there were notices on how to deal with RFI. Granted, these were Crown Vics and Broncos but there has to be something figured out somewhere. I’ve got ferrite everywhere and a common mode choke too. Only thing I have not tried is wrapping foil around in the engine compartment.

My first guess is the interference is air-born. I had an issue like this on a 2003 Tahoe. What I did was bond everything with 1" flat brad (if you need some I have a fair amount). When I say everything, I mean everything was strapped including the exhaust system and the antenna base. I won. I later, and by accident, discovered the noise was coming from my aftermarket HID ballasts. Did you happen to add any aftermarket accessories to your truck?

I'm thinking it may be the injectors. There are, if memory serves me right, up to 6 injection events per compression stroke. I can't think of anything else that would cause the noise. My 2015 Cummins doesn't have this issue. I run 2 meter/70cm FM and sideband using a roof-mounted dual-band (yep, I drilled a hole for an NMO mount, the hardest thing I ever did) and HF on a Yaesu FT991 with an ATSA120 mounted on my goose ball mount (home built) well-grounded to the vehicle. Both radios and the ATAS120 are bonded to the truck and power for both radios comes directly off the passenger side battery.

I've never seen anything from RAM regarding RFI but I've never looked either. Search the internet for "2016 ram body builder", you will find RAM publications targeting the builders that add such things as towing, flat beds, and even ambulances to the HD chassis.

 

[Mister Luck]

Here’s one on grounds

http://www.rambodybuilder.com/2010/docs/wd/dr/8w91connectorgroundsplicelocation.pdf

 

[Sailing Santa]

Update:
The chassis/engine grounding appears functional at all points. Now I’m wondering about the acceleration pedal circuit, and wondering if I’m seeing (hearing) PWM noise. (Pulse width modulation). I’ve got some time coming up this weekend with a spectrum analyzer, probes, small shielded loops and a large coffee pot.

 

[Mister Luck]

if you have an oscilloscope or any scope

Electronic Throttle Control (Drive By Wire) - Picoauto Library

The throttle cable has almost become redundant on today’s motor vehicle. The drive-by-wire system is by no means a new concept as it was introduced by BMW on

www.picoauto.com

 

[BossHogg]

Update:
The chassis/engine grounding appears functional at all points. Now I’m wondering about the acceleration pedal circuit, and wondering if I’m seeing (hearing) PWM noise. (Pulse width modulation). I’ve got some time coming up this weekend with a spectrum analyzer, probes, small shielded loops and a large coffee pot.

I don't believe the accelerator pedal provides a PWM signal. The accelerator provides two voltage levels in opposition of 0 to 5 volts to the ECM.

 

[Mister Luck]

As with all radio and extra electronic stuff an auxiliary battery or capacitor is going to be introduced.
Probably the isolator relay, what brand of BIM manager ?

 

[WY7CH]

I am having same issue on 2009 Dodge gas. Running a yaesu 891. tried hooking to stand alone power still have RFI. If park under base antenna will pickup RFI in home. Tried ferrite choke on radio side and antenna side. if You come up with solution let me know. I will do th3 same

 

[Mister Luck]

Carbon black (as graphite)
pigment added to most rubberized products (vacuum hoses, tires, radiator hoses, rubber door seals) are able to conduct ( a surprisingly sufficient amount of ) electrical current.

Late model wheel bearing races are installed as one piece with wheel speed sensors attached and sensor leads that are shielded.

Wheel bearings themselves are not magnetized but eventually become magnetized through static energy of tire and brake component rotation and friction.

Some suggestion has been made that tires act as grounding points for a vehicles chassis and grounding straps that attach to the vehicle frame which are then allowed to touch the road surface while in motion are not necessary.