RADIO NOISE? High pitch whine!!!

[Hurricane145]

Sounds like classic alternator whine to me.

 

[Shadetree Mechanic]

Proper dc ground and RF ground are two different things. RF does some funny things and it can be hard to imagine what it is doing when you are used to thinking about dc or even conventional ac power. I wonder if some ferrite rings on the injector power supply wires would help. This will usually clean up a noisy wall wart in the house. Definitely do the RF bonding as was suggested. I think that's your best bet as it has fixed the problem for another member.
Chris

 

[Mark Malcomb]

Welcome to my world of PWM, Awesome technology, Its everywhere in our lives. I manipulate pulse width through a signal generator in my work to do many things like
dimming fluorescent lights, motor speed control etc. I have noticed terrible noise from my PWM pool pump. The great guys on this sight had a cure. A 44 mag filter through its center. In reality I'm waiting for a good filter technique, if it exists. I'll stay tuned for a solution. Feel your pain.....MM

 

[Handy Andy]

PWM is a good ay to look at this...

Square wave - and turns into a spurries with tons of smaller sine waves "Ringing" thru anything metal that can accept and re-radiate the noise - propagating thru a harness onto the rest of the vehicle and if possible - even into the vehicles parked, waiting at the light - next to you...

All you need is to get the lowest inductive path for RF to locate ground and a simple copper braid strap mounted from an upper bolt on that mount past the shock rubber mount into the Frame member bolt underneath or alongside is about the best you can do - aside from rerouting onto re-braiding a harness just to equalize the currents from the signals the injector pulse generates - like they do with CATV and Hi-Speed cable and telephone systems to offset their losses in long runs.

It's never easy...

This effort so you know, will not remove the noise, just lessen it. You still have to address the injector onto the harness ground points for those injectors or even the cam to injection timing system that exists to make sure the injection occurs at the right moment - those things are like a tiny reluctors on the camshaft and not always properly shielded. All it does is help the engine do a best guess amongst all the other sensors for engine loading and acceleration.

Using the diesel as a platform, they're now going into GDI - direct inject into cylinders for even Gas powered vehicles and their associated headaches so as you work with this - I've seen something similar in the passenger car injector systems begin to move over into cylinder injection versus the manifold injector types...

 

[Buzzard78945]

Those braided ground straps that always get in the way. Those are bonding straps. You may need to add more.

"
Basics

A vehicle is not a ground plane, but rather acts like a capacitor between the antenna and the surface under the vehicle which acts as the ground plane. Since the surface in question is a poor conductor of RF, ground losses occur. If we wish to maximize the system efficiency (the mobile station as a whole), we need to maximize the RF continuity of the vehicle, hence proper bonding. Obviously, proper antenna mounting, and placement are important too. Remember, it is the metal mass directly under the antenna, not what's along side, that counts. And a ground strap is not a replacement for proper mounting!

Bonding also minimizes the leakage of RFI into (ingress) and out of (egress) the various bolted on parts of the vehicle. The exhaust and tail pipes are good examples of RFI egress. Bonding horizontal surfaces (trunk lid, hood, etc.) will have a greater effect than bonding vertical ones like doors, and hatches. It is not uncommon to see a 20 to 30 dB drop in received noise levels once they're properly grounded. Bonding is especially important for body-on-framevehicles, like pickup trucks. In these cases, the bed and cabin should be bonded to the main frame as well as between the bed and the cabin to prevent ground loops.

Remember that RF must return to its source. Low mounting forces a larger portion of this return current to flow through the lossy surface under the vehicle, rather than through the (less lossy) vehicle's superstructure. Therefore, it is easy to see why proper mounting, and proper bondingare requirements to maximize radiation efficiency.

There are a few pundits who are under the misguided belief, that running a braided bonding strap along the frame of a body-on-frame vehicle, bonded every few inches, will drastically improve the less than perfect ground plane a vehicle represents. It won't!

There is one important item to keep in mind about bonding specifically, and noise abatement in general; you can't always tell there has been an improvement by just listening! The reason centers around the AGC circuitry. That issue is covered in the high-lighted article.

From this link....
http://www.k0bg.com/bonding.html

The main link is this.....
http://www.k0bg.com

got it thanks!

 

[Buzzard78945]

I’m going to add a ground strap to the frame from bed at lunch!

 

[OldTech03]

I understand completely where you are going with the ground situation I’ve chased my tail many of times with ground issues... I did run a jumper from battery negative (where radio is grounded at on the battery terminals ) to the antenna mount.. same issue... I also know for a fact the engine ground (block) to battery is good, and the bed to frame ground is good and the frame ground to battery is good

DEFINE GOOD grounds IN EXPLICIT TERMS. In another words how many places is it grounded? what kind of wire is used to affect the grounding? from what point to what point are the grounds being run? How long are the ground straps? The antenna needs a ground but not a wire run to the battery that may cause more issues than it solves.
I would be interested in knowing what noise the radio has with no antenna attached if the noise goes completely away with the RF gain wide open and the volume all the way up then you have an issue of a different magnitude.
Just some food for thought it's really hard to recommend any course to take unless we have established beyond a shadow of a dought that the injectors are the only culprit.

 

[Buzzard78945]

DEFINE GOOD grounds IN EXPLICIT TERMS. In another words how many places is it grounded? what kind of wire is used to affect the grounding? from what point to what point are the grounds being run? How long are the ground straps? The antenna needs a ground but not a wire run to the battery that may cause more issues than it solves.
I would be interested in knowing what noise the radio has with no antenna attached if the noise goes completely away with the RF gain wide open and the volume all the way up then you have an issue of a different magnitude.
Just some food for thought it's really hard to recommend any course to take unless we have established beyond a shadow of a dought that the injectors are the only culprit.

noise is only when truck is running engine off noise gone... I’m going to add ground strap from bed to frame tonight didn’t get a chance to at lunch

antenna is grounded to bed showed good resistance to battery... big ass cm flat bed should have good ground plane????

Like I said I killed half the engine ran it off of 3 cylinders (not running off of all 6) and the noise changed. Only thing I Can do to chance noise in radio I can post a video of the noise if you would like

 

[Buzzard78945]

So, the noise is a high whine while the engine is running, & only when the engine is running? Not a clicking/ buzzing??
I wonder if it is the alternator, have you pulled the belt & started the truck to see if the noise is still there? I drive something similar, & have no issues myself... had a Toyota that had a nasty alternator whine. The ONLY thing that did anything to remedy that was a VERY large capacitor inline from the battery. Nothing else helped.

I have not pulled the bet it’s a bitch to get to... I have to pull air cleaner box and such I may try tonight along with adding ground strap to bed

 

[Buzzard78945]

Proper dc ground and RF ground are two different things. RF does some funny things and it can be hard to imagine what it is doing when you are used to thinking about dc or even conventional ac power. I wonder if some ferrite rings on the injector power supply wires would help. This will usually clean up a noisy wall wart in the house. Definitely do the RF bonding as was suggested. I think that's your best bet as it has fixed the problem for another member.
Chris

I’m at the point of trying that thanks I just need to order some

 

[OldTech03]

noise is only when truck is running engine off noise gone... I’m going to add ground strap from bed to frame tonight didn’t get a chance to at lunch

antenna is grounded to bed showed good resistance to battery... big ass cm flat bed should have good ground plane????

Like I said I killed half the engine ran it off of 3 cylinders (not running off of all 6) and the noise changed. Only thing I Can do to chance noise in radio I can post a video of the noise if you would like

You didn't read my post quite right. Do you have the noise with the antenna not connected and the volume wide open and the rf gain full on and no squelch? there I think I covered everything. I didn't say with the engine off.

 

[Dmans]

BONDING STRAPS = THE SHORTER THE BETTER!!!!!!!!!!!!

(And what OldTech03 said)

Good Luck

73
David

 

[Slowmover]

I have an ‘04 CTD.

ALLEN APPLEGATE is the mobile radio guru if for no other reason the ENORMOUS amount of time it took to set up his Guide.

www.K0BG.com

The section on Bonding is comprehensive.

I started on my truck a short while ago. A few of us with CTDs on this site recently joking we are spending time/money the truck needs elsewhere.
But, priorities.

Last week I ordered about 50’ or 100’ of 3/4” flat-braided tinned woven copper. Plus internal/external tooth washers to work with 1/2” #10 screws. Then 6-AWG tinned copper lugs. Loaded up on some Dremel brushes.

A whole lotta 6” & 9” straps is envisioned till I crawl back underneath and make notes. I’ve seen, bonds short as possible, not to exceed 10”.

A variety of copper braid widths appears to be the best direction. But I had to start somewhere (ordered more than I’ll use on this project, have others).

The horizontal surfaces get first attention. Bed-to-cab both sides, all four bed corners. Hood. Cab to frame. Exhaust — the big antenna — will have four straps. Have seen 1.75” batt cable used for this with big worm-drive clamps.

The factory DC grounds I’ve already cleaned up (second time last ten years in Texas). Some should be improved. That’s another phase.

Alternator mount bolts?

In-tank fuel pump DC wiring?

Auto trans trucks (Mommy trucks) have a few more controls than
the Man trans trucks. APPS or something.

There’s a whole history of mobile Amateur Radio you’ll come across that’s fascinating. No one found it easy, not the US Army with their needs or General Motors with in-car AM/FM. Everyone had to learn.
.

 

[Buzzard78945]

I can’t upload video or audio file to this thread from my phone may try it on the computer in a bit... BUTT IM ABOUT TO PUT GROUND STRAP ON BED SEE HOW THAT WORKS OUT FOR ME

 

[Buzzard78945]

You didn't read my post quite right. Do you have the noise with the antenna not connected and the volume wide open and the rf gain full on and no squelch? there I think I covered everything. I didn't say with the engine off.

Oh I got you hold on let me try antenna disconnected GOOD CALL! ...

no noise when antenna disconnected must be a ground plane issue!!! I’m a firm believer in diagnostics via process of elimination... let me ground strap bed real quick