RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Commercial, Professional Radio and Personal Radio > CB Radio Forum


CB Radio Forum - Discussions regarding Citizens Band Radio (CB)

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 08-24-2017, 10:58 AM
Member
   
Join Date: Aug 2017
Posts: 6
Smile Noob with engine noise on CB. Yes, I searched. :o)

Hi,

Been looking around this forum searching for solutions to an engine noise problem. No joy yet.
I am hearing engine noise, especially while accelerating, that is making the radio almost unusable while the vehicle is in motion. Not so bad sitting idle, but it is still present.

Here is my setup:
Vehicle: 2000 Ford 350 7.3 Diesel Crew Cab Long Bed
CB: Cobra LX 29 BT (received as gift)
Antenna: Firestik 5 foot fiberglass tune-able tip

CB Power is straight to battery with inline fuse as suggested in these forums.
CB Ground, also with inline fuse, is to body under hood where a factory ground bolt was located, on that same bolt is a ground from somewhere else attached to it, but I do not know from where/what.
CB chassis ground using heavy stranded battery cable about 12 inches long to bolt on floor of cab.
Antenna is mounted center of crew cab roof using a dome mount.
Antenna cable does not run parallel to any power for long distance.
Antenna cable does not have a big loop of extra cable anywhere.
Antenna cable 2.5 feet extra was tied up loosely, not circular, in the middle of the bundle and tucked away neatly.

SWR from meter shows ~1.2
SWR on radio shows ~ 1.1

NB/ANL On or Off makes little difference while the vehicle is in motion.
NB/ANL On does help while vehicle is at idle.

RF Gain knob on CB, with engine on, turned up just past half way makes it better. Turning the knob up further makes it worse. Turning it down, makes it quieter on my end of course, but then I do not hear much coming in, relatively speaking. (not much action on CB around here to begin with)

Delta tune knob set in middle and no touchy.

A magnet mount antenna nets the same results, if not somewhat worse.

I have no other CB radio nor do I know anyone with a CB radio.

I have a Pro-97 scanner to verify transmit, but that does not prove much as I have to set the scanner close enough for me to hear it while keying up the CB.

I have driven to a parking lot across the road from a truck stop and asked about how my cb transmission sounds, as well as while driving on the highway nearby. So far the response is, "Sounds good"

Interestingly, the only response I get from drivers are those that are about 8 to 10 miles away. I ask them where they are and which direction and then I check the map for distance. On one occasion, the driver said he would keep talking to me and let me know where he was when I started to fade out. That was about 14 miles. I thought these distances were outstanding according to my limited knowledge of CB.

Any ideas? I'm all out.

Thank you,

e
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 08-24-2017, 2:11 PM
Member
   
Join Date: Mar 2002
Location: New Orleans region
Posts: 2,416
Default

Quote:
Originally Posted by emzungu View Post
Hi,

Been looking around this forum searching for solutions to an engine noise problem.

Here is my setup:
Vehicle: 2000 Ford 350 7.3 Diesel Crew Cab Long Bed
CB: Cobra LX 29 BT (received as gift)
Antenna: Firestik 5 foot fiberglass tune-able tip
e
First of all using a diesel, you should not have any engine noise. But I will say that you could be hearing noise from your alternator. This will sound like a whine as you change engine speed.

So I will ask a couple of loaded questions. Just how old is the batteries in the truck. You should have 2 of them. These act as a filter of sorts when they are new. As the batteries age, the internal resistance goes down and the filtering they can supply also goes down.

Generally the auto batteries are only good for about 3 years max. After that they are at end of life and you should start seeing issues like the engine cranks slow, the dash radio might start having issues with the time going crazy when you start the engine.

If you have a digital volt meter, pull it out and wipe the dust off of it. Before you start the truck up in the morning, measure the battery terminal voltage. Depending on the age of the batteries, you might see something between 11 volts and as high as 13 volts. The higher voltage is a better battery.

Next, put your voltmeter into the AC volt mode and again put the probes on the battery terminals. What your looking for now is a very low AC voltage with the engine running. Something in the order of 150 millivolts or less. This is checking to see if the diodes in the alternator are all working and are in good order.

The next few steps will make use of the volt meter back in the DC mode. Use a sheet of paper to record your meter readings. What your looking for is the point where the battery DC voltage starts to drop. These measurements are all done with the engine just sitting there at an idle.

First measurement is done with nothing turned on in the vehicle. Make sure you have the fan and the Air Conditioner shut off. Write down the reading.

Now turn on your headlights on low beam and write down the battery voltage.

Now put your headlights on high beam and write down the battery voltage.

Next, turn on your windshield whippers and record the battery voltage.

Next add the fan on say the second speed setting and record the battery voltage.

Next add the air conditioner with the fan set on the second speed selection and record the battery voltage.

Someplace along these test steps you should have found a point where the battery voltage went down as you made a change in the electrical load.

Just where the battery voltage started to drop will depend on how good your batteries are, how large your alternator rating is and if your idle is set to the factory setting for engine speed.

Only you can tell us where the battery voltage started to drop. I can't tell from afar where this took place. It also would depend on how large the alternator was in the truck. Most diesel trucks have a good sized alternator that more than likely will be in the range of 120 amps or larger. This, under normal operating conditions should hold the electrical load of the truck. BUT, if the alternator is not putting out enough current at an idle, then you will find this out with what we just did above for testing.

What I am trying to say, is that you should see some where in the order of 13.2 to 14 volts under normal loads. If you go below this, then you need to investigate why the voltage is not maintained.

Now that you have dug into the electrical charging system, I have sort of skirted the original question you came to us with. But the alternator is generally the first source of noise. You sort of gave the first indication of this in the way you stated the noise problem.

You can try a second test for noise. Most of the newer trucks have an electric fuel pump. This can be another source of radio noise. But it really won't change with engine speed. To look at noise from the fuel pump, set your radio on a weak station. Do this with the truck engine not running. Turn the truck off and wait about 10 minutes. Now turn the ignition on, but leave it in the accessory position and don't start the engine. If it is the fuel pump, it should shut off after it builds up the fuel pressure. This will only be about 10 to 30 seconds. If the noise goes away, you could have the fuel pump noise causing some of the noise problem you have.

Now start the engine and see of the noise gets worse with the engine running and the alternator trying to charge the batteries.

Don't forget that the fan motor for the air conditioning system and the windshield whippers can also generate noise.

Anyway, that's about the simple way of trying to point the finger to noise that can be generated with the vehicle standing still. There are other areas that can come into the picture with the vehicle moving, but I won't go there now.
__________________
Jim
Reply With Quote
  #3 (permalink)  
Old 08-24-2017, 2:27 PM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Sep 2006
Location: Davenport,Fl.- home to me and the gators and the skeeters.
Posts: 1,384
Default

Jim, where you post about the test for voltage when turning on the headlights, then windshield wipers, etc., should he leave these on as he continues on down the list?
__________________
Freedom, a beautiful way of life.
Pro-107, Pro-44, Pro-94, Pro-2006, DX-440
YAESU FT-2900R, YAESU FT-101EE, RS HTX-202, ICOM IC-2AT, RS BTX-121, BAOFENG UV-5R
Reply With Quote
  #4 (permalink)  
Old 08-24-2017, 2:43 PM
MCore25's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jun 2013
Location: Lone Star Republic
Posts: 2,399
Default

Quote:
Originally Posted by jim202 View Post
First of all using a diesel, you should not have any engine noise.
Unfortunately not true for Ford Powerstrokes. The 7.3, 6.0 and 6.4 sing over the spectrum. They commonly resonate at around 2000 rpm on 146.520 MHz. Generally however, it's not something the driver ever notices (but those vehicles within about 50 feet). It varies with engine speed so it could be the injection system or the alternator but the high pressure oil-based injection system of the 7.3 was phased out for a common rail based system with 6.0 and newer engines. Haven't noticed it with the 6.7 though.
__________________
If a repeater IDs and no one is on frequency to hear it, does it even make a sound? Yes, because KC5MVZ is monitoring you
Reply With Quote
  #5 (permalink)  
Old 08-24-2017, 3:12 PM
DJ11DLN's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Mar 2013
Location: Mudhole, IN
Posts: 1,232
Default

Quote:
Originally Posted by jim202 View Post
First of all using a diesel, you should not have any engine noise...
Incorrect. The Powerstroke series is a HEUI, or Hydraulic Electric Unit Injector, engine. The ones I've been around make anywhere from moderate to a you-know-what ton of RF noise, thanks to the electronics associated with this type of engine. It's -- usually -- not much of a problem on VHF & up FM but I can see where they'd make trying to run a CB, or an HF Ham rig for that matter, a real pain. The later versions seem to be a bit cleaner...they just like to self-destruct, where the old 7.3 was a Maytag.

The rest of your post is spot-on.
__________________
If it looks stupid but it works...it ain't stupid.
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 08-24-2017, 3:14 PM
KK4JUG's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2014
Location: Columbus, GA
Posts: 829
Default

How 'bout something as simple as a filter in the power line?
Reply With Quote
  #7 (permalink)  
Old 08-24-2017, 3:17 PM
KK4JUG's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2014
Location: Columbus, GA
Posts: 829
Smile

Quote:
Originally Posted by MCore25 View Post
Unfortunately not true for Ford Powerstrokes. The 7.3, 6.0 and 6.4 sing over the spectrum. They commonly resonate at around 2000 rpm on 146.520 MHz.
Do you have to get a ham license to drive the truck?
Reply With Quote
  #8 (permalink)  
Old 08-24-2017, 4:54 PM
Member
   
Join Date: Aug 2017
Posts: 6
Thumbs up

--> KK4JUG Good thing I am currently studying for the tech ham ticket so I will be able to legally drive the truck instead of just monitoring it. ) It has over 302,000 miles of monitoring and still pulls strong. Like a Maytag <--DJ11DLN


Firstly, thank you all for the quick responses. Much appreciated.

I went through the task list provided by jim202. Thanks jim202.
Below are my findings:

The nose is a buzzing with a slight wine? Hard to describe. I took the following measurements today. I began with the truck not having been started for ~ 24 hours. After the measurements, I went for a short drive out to the nearest asphalt road to verify noise once more. Under acceleration, it is still there as expected.

jim202's task list:

Both batteries were replaced 4-4-15 (Wal-Mart EverStart Maxx)
Alternator was replaced 6-15-14 (Motorcraft 110 amp iirc)

No issues observed regarding clock or slow cranking.

Ran the voltmeter through the dish washer prior to use to get the dust off. )

Batteries Cold - Engine Off:
Right Battery 12.59 Left Battery 12.60
Left Battery = CB power (does it make a difference which battery it is hooked to?)
Left Battery to CB ground = 12.60

Meter in AC Volt mode - Engine On (at idle)
Right Battery = 0.017 Left Battery = 0.012

Meter in DC mode - Engine On (at idle)
Nothing turned on: Right = 14.47 Left = 14.47
Headlights Low Beam: Right = 14.49 Left = 14.49
Headlights High Beam: Right = 14.49 Left = 14.49
Wipers On: Right = 14.46 Left = 14.46
Fan on Speed 2: Right = 14.48 Left = 14.48
A/C on and fan at speed 2: Right = 14.49 Left = 14.49

The above measurements were done one at a time, not cumulative. Meaning, Headlights were turned off before moving on to the Wipers, etc.

--> KC4RAF I then went back and left each thing on while going to the next. Meaning, Headlights left on then moving on to the Wipers and left them on, etc. The measurements were the same or very, very close.

Fuel Pump: Did not notice anything while performing those tests.

--> KK4JUG I did some searching in other forums regarding power line noise filters. Also read some reviews of a couple of the products offered. Seems like mixed results and happiness levels.

The more I read, the more it seems that the 7.3 diesel is prone to give fits in this way. For CB's and ham's. That is not encouraging. Love the truck, but it does have it's quirks so I may have to add this one to the list. That kind of changes my plans though. Once I get my ham ticket I may not be putting a mobile unit in the truck after finding this out.

--> MCore25 may be on to something. There is talk about it in the tuck forums I found. Some of the stories/symptoms are crazy.


Thanks ALL for the input. I really do appreciate the time and suggestions and jokes.

e
Reply With Quote
  #9 (permalink)  
Old 08-25-2017, 2:05 AM
madrabbitt's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Apr 2004
Location: NM
Posts: 499
Default

Quote:
Originally Posted by KK4JUG View Post
How 'bout something as simple as a filter in the power line?
Seriously though.

Just get a pair of clip on RF chokes and put them on the power and ground and see if that does anything.

I mean, they're less then a couple bucks each.
Reply With Quote
  #10 (permalink)  
Old 08-25-2017, 7:43 AM
MCore25's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jun 2013
Location: Lone Star Republic
Posts: 2,399
Default

Quote:
Originally Posted by emzungu View Post
Both batteries were replaced 4-4-15 (Wal-Mart EverStart Maxx)
That's just about service life.

I've got an EverStart Maxx sitting in the back of my pickup (I have a small core collection back there right now) that I put on my Trailblazer in April of 2013. It would no longer hold a charge as of February 2015. So yes, it's still under warranty until April but I won't take it back to Walmart (since it's the warranty replacement of a warranty replacement's warranty replacement).
__________________
If a repeater IDs and no one is on frequency to hear it, does it even make a sound? Yes, because KC5MVZ is monitoring you
Reply With Quote
  #11 (permalink)  
Old 08-25-2017, 8:15 AM
jonwienke's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jul 2014
Posts: 4,136
Default

https://www.amazon.com/Magnum-XLF-20...dp/B01IC27LHW/
__________________
Uniden scanner internal GPS installations--making mobile scanning work the way it always should have.
Reply With Quote
  #12 (permalink)  
Old 08-25-2017, 12:19 PM
Member
   
Join Date: Aug 2017
Posts: 6
Default

Thanks again for the suggestions!

I will look into the RF chokes. Seems I saw one or two laying around here somewhere. If that's a no go, I may look into the powered noise filter version.

Thanks!!

e
Reply With Quote
  #13 (permalink)  
Old 08-25-2017, 6:23 PM
RFI-EMI-GUY's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2013
Posts: 1,572
Default

Get a length of RG58 (or better) coax with two PL259 connectors long enough to reach from the radio and to the engine compartment.

On the far end wire up a jumper using a foot or two of wire from the center conductor to shield. An SO239 and some solder would be best way to connect.

Coil that jumper into a small coil about 3 inches diameter. Use it to test around the various electrical components under hood.

My guess is that the electronic injectors are "singing". The fix will be ferrite chokes and aluminum tape to ground.
__________________
"Have Spectrum Analyzer, - Will travel" "Going Green"
Reply With Quote
  #14 (permalink)  
Old 08-25-2017, 6:32 PM
RFI-EMI-GUY's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2013
Posts: 1,572
Default

here you go! this guy went to a lot of effort. I would look for the source first.

Common rail diesel* Interference suppression
__________________
"Have Spectrum Analyzer, - Will travel" "Going Green"
Reply With Quote
  #15 (permalink)  
Old 08-25-2017, 7:19 PM
Member
   
Join Date: Aug 2017
Posts: 6
Default

Looked all over. No one has ferrite chokes around here. Was ordering a Baofeng from Amazon and threw in some ferrite chokes as well. Will try this in a couple of days after they arrive.

RFI EMI GUY - ain't no way I am going to that length as the dude with the Trooper. Nope. I will just have to suck it up. Good read though.
Thanks.

e
Reply With Quote
  #16 (permalink)  
Old 08-25-2017, 8:01 PM
RFI-EMI-GUY's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2013
Posts: 1,572
Default

Quote:
Originally Posted by emzungu View Post
Looked all over. No one has ferrite chokes around here. Was ordering a Baofeng from Amazon and threw in some ferrite chokes as well. Will try this in a couple of days after they arrive.

RFI EMI GUY - ain't no way I am going to that length as the dude with the Trooper. Nope. I will just have to suck it up. Good read though.
Thanks.

e
I think the guy with the trooper tried to bond everything in sight before he traced it back to the injection system. You might check with Ford to see if they already have an RF suppression kit for that engine. I would use those clamp on ferrites as well as aluminum tape on the offending wiring.
__________________
"Have Spectrum Analyzer, - Will travel" "Going Green"
Reply With Quote
  #17 (permalink)  
Old 08-25-2017, 8:39 PM
Member
   
Join Date: Mar 2002
Location: New Orleans region
Posts: 2,416
Default

Quote:
Originally Posted by KC4RAF View Post
Jim, where you post about the test for voltage when turning on the headlights, then windshield wipers, etc., should he leave these on as he continues on down the list?
Yes, you want to keep adding to the load on the electrical system as you progress. In most vehicles, you will hit a point where the voltage will start to drop. This is what your looking for. Need to find out if your alternator has enough guts to hold the normal load.

Most people will not be using the Air conditioner set on the high fan speed with the whippers going and the high beam lights on at an idle.

I have to agree that in some diesels, the electrical noise is bad. I happen to own a 2004 with the 6.0 and don't have the noise problem.

The ferrite cores come in a number of options for their ability to suppress noise based on frequency. So be a little selective as to the ones you get. Make sure they cover the frequency range your concerned with.

Good luck trying to eliminate or reduce the noise to a usable level.
__________________
Jim
Reply With Quote
  #18 (permalink)  
Old 08-26-2017, 4:31 AM
Member
   
Join Date: Dec 2007
Location: Mojave Ca
Posts: 632
Default

Hello emzungu: I didn't see anyone say to remove the antenna coax connector from the radio and see if the noise goes away. This will allow you to trouble shoot and isolate if the noise is coming in from the antenna or power wires. Most likely the noise is being radiated into the antenna and being picked up by the radio, based on experience.

EMI Guy had a great suggestion to use a length of coax plugged into the radio, with a few turns of wire ( not critical I use 2 turns on a one inch diameter ) from the center to the shield, this allows the radio to now become a noise sniffer. Do not transmit with the jumper. This is now a receive only sniffer will allow you "probe the field" and find the RFI source. Using the radios RF Gain to adjust the radios sensitivity will allow you, or should allow you to isolate the noise source in the truck. You can probe around the truck with the radios volume up so that you can hear the noise when to get close to it. Be advised that you may hear different noises that you aren't hearing in the radio with the antenna connected, just ignore these.

Measuring the trucks voltage will just run you in circles, not isolating the RFI noise source.

If it is the injector wiring it can be shielded and ferrite cores can be placed over the wiring to reduce the RFI radiation into the air. As already said. Ford should have some type of fix for this again as said.

RFI (Radio Frequency Interference) is not the easiest thing to fix as there are many things to consider. And I am sure there are Ford Diesel Injector noise fixes on the net some were, just got to keep pounding the key board. See:
HF RF Noise mobile Powerstroke Diesel Ford

Good luck please let us know what the fix is.

Jay in the Great Mojave Desert.
Reply With Quote
  #19 (permalink)  
Old 08-26-2017, 5:47 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Sep 2006
Location: Davenport,Fl.- home to me and the gators and the skeeters.
Posts: 1,384
Default

Thanks Jim for the note on additive load on the electrical system. Thought that it would be that way, just wanted to make sure. Thanks again sir, much appreciated.
__________________
Freedom, a beautiful way of life.
Pro-107, Pro-44, Pro-94, Pro-2006, DX-440
YAESU FT-2900R, YAESU FT-101EE, RS HTX-202, ICOM IC-2AT, RS BTX-121, BAOFENG UV-5R
Reply With Quote
  #20 (permalink)  
Old 08-26-2017, 8:57 AM
Member
   
Join Date: Aug 2017
Posts: 6
Default

Regarding the coax coil: I will see if I can get someone to assist me on that. These 7.3 diesels are loud and there is no way that I would be able to hear anything on the radio with the engine running and hood up.

Thanks again for everyone's suggestions. Very much appreciated.

e
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 7:42 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2015 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions