60 ARB CB Help Needed

[MJM]

Problem Fixed only 1 year later it was the spark plugs. Make sure you have real resistor plugs




I have an 83 FJ60 with a Uniden CB mounted wired straight to the battery. I do have an noise filter installed on the incoming power. 4’ Firestick tuned to below 1.5 SWR. The problem I have is lots of noise with the truck off it works (I think) once the truck is started I get a buzz and an a sound that follows the RPM levels making it not work. The cable is 10’ long and runs up the passenger side near the coil the power wires are tucked into the fender. What can I do to help!
I have an event in 3 days and want it to work.

THansk
MJM

 

[MJM]

Any one

Could it be a ground issue with the firstick? How does that ground to the bumper?

 

[Miescha]

wow - there are so many potetial problems that I'm not sure where to start. Here is my best shot though.

I do have an noise filter installed on the incoming power.

More details please on this 'noise filter' on the power feeds.

4’ Firestick tuned to below 1.5 SWR.

Which 4' Firestick are you using? Where is the antenna mounted and how? What coax is used? Is the 1.5 SWR across the spectrum or at a given freq - what freq?

The problem I have is lots of noise with the truck off it works (I think) once the truck is started I get a buzz and an a sound that follows the RPM levels making it not work.

Can you be more specific on when the noise occurs? Is it only when the engine is running? Is it only when you transmit or one receive also? Can it be adjusted out with the schelch at any level?

The cable is 10’ long and runs up the passenger side near the coil the power wires are tucked into the fender.

Are you referrig to the coax antenna cable or the power cable? If coax, how did you get a 10' cable as they are usually sold in 9' or 18' lengths. What did you do with the excess cable (if any) as coiling it can create an RF choke.

We first need to identify the noise so we know if it is RFI, EMP or AFI and whether it is induced, inducted or received. My very uneducated guess at this early point would be igition noise coupled with some electronic motor noise and possibly alternator whine. Again, being very specific as to when the noise occurs (truck on/off, all other electronic stuff such as stereo, A/C, etc. . . on/off) and whether it occurs with transmit or receive or both and whether it can be schelched).

Also, depending on the antenna being used and how it is mounted, you may also have a ground loop problem leading to alternator whine. Again, these are just common problems and require much more info to diagose.

I'll wait for more info - good luck until then!

 

[MJM]

Thanks for the help

wow - there are so many potetial problems that I'm not sure where to start. Here is my best shot though.



More details please on this 'noise filter' on the power feeds.

PLF10C - Power Line Filter and Cord (Most Common)

Above is the powerstick

Which 4' Firestick are you using? Where is the antenna mounted and how? What coax is used? Is the 1.5 SWR across the spectrum or at a given freq - what freq?
FS Series Fiberglass Antenna # 5/8 Wave # Tuneable Tip # 650 Watt Power Rating
UNIDEN PRO538W 40-Channel

All SWR is less than 1.5 across the spectrum


Can you be more specific on when the noise occurs? Is it only when the engine is running? Is it only when you transmit or one receive also? Can it be adjusted out with the schelch at any level?

Noise is only when truck is running, it will whine with RPMs it can not be adjusted out with schelch the RF knob will change it from a static to a whine


Are you referrig to the coax antenna cable or the power cable? If coax, how did you get a 10' cable as they are usually sold in 9' or 18' lengths. What did you do with the excess cable (if any) as coiling it can create an RF choke.

The cable could have been 9' it was from Radio Shack there is no extra cable to coil up.

We first need to identify the noise so we know if it is RFI, EMP or AFI and whether it is induced, inducted or received. My very uneducated guess at this early point would be igition noise coupled with some electronic motor noise and possibly alternator whine. Again, being very specific as to when the noise occurs (truck on/off, all other electronic stuff such as stereo, A/C, etc. . . on/off) and whether it occurs with transmit or receive or both and whether it can be schelched).

No A/C in use, see above.

Also, depending on the antenna being used and how it is mounted, you may also have a ground loop problem leading to alternator whine. Again, these are just common problems and require much more info to diagose.

Antenna is mounted to front ARB bumper on the upper tab with a stud mount, there is new thick powdercoat on bumper if that means anything.


I'll wait for more info - good luck until then!

I have read a few past post and want to thank you for your help long time cruiser fan here but a true novice with CBs.

 

[Miescha]

First, don't sweat the novice status. I think most of the radio (CB or VHF/UHF or HF) stuff is pretty complex. I'm always looking for an easy 'plug it in and slap it on the truck and start using it' solution and it just doesn't exist unless you get real lucky. So again, don't sweat it - the stuff can be a lot more complicated than it should be.

All that aside, I've got one more question (sorry to be such a hassle). If you have the truck off, it sounds like you can transmit just fine - so you can talk to someone and hear them just fine. Can you confirm that you've made contact with the truck off and all is fine?

Next, turn the truck on and confirm that the noise is there when not transmitting. Then, disconnect the antenna coax from the radio and see if the noise is still there or if it goes away. This will help determine if the noise is from the power supply (if it is still there then it is the power supply), or the antenna (if it goes away, it is coming through the antenna coax).

BE VERY CAREFUL TO NOT TRANSMIT WITH THE ANTENNA DISCONNECTED - this can fry your radio - so just listen.

My guess is the noise will disappear and that means you have interferrence in the antenna coax. The easiest first step (though it requires spending some money) is to buy some better quality coax - I'd suggest the Firestick Firering system since you already have their antenna, but given your time cotraints it may not be possible.

Next, you need to check your coax for a ground short. This could cause your antenna to ground through the the coax back to the radio, thereby giving a good SWR reading even though you really don't have a ground (and you will not get much in the way of transmit quality either).

That brings us to your mount. The ARB front bumper is a very difficult mounting point as you do not have a DC ground and you have a relatively poor image (ground) plane. You can solve the lack of DC ground by using a ground strap - this will help a lot. The image plane will also be helped by bonding the ARB with the truck frame - but it is a compromise regardless and your signal image will be distorted regardless. All that said, I use a Firestick Firefly mounted to my front ARB bumper in the exact same location as you and I get great range on both transmit and receive with absolutely no noise problems. But I spent a lot of time bonding the ARB to my frame to achieve this, and I spent a lot of time bonding all the doors, hood, hatch, and exhaust system in order to achieve a better image (ground) plane.

So, check the noise without the antenna connected, if it goes away, test the coax for a ground short or, if you can get better coax and don't mind spending the money, buy better coax (though you'll still need to check for ground short after the install to make sure you put the connector on correctly).

Let me know what you find and we'll attack the problem accordingly.

Good luck.

 

[MJM]

Ground Strap

How do I make or install a ground strap?

 

[Miescha]

Sorry for the delay - I'm having a tough time finding a picture and I'm connecting from my mobile phone so I'm a bit limited without my computer and files.

Basically, you're looking for a wide flat braided wire. The reason for the wide flat rather than typical round wire is that RF flows on the surface of the wire rather than through the wire and a wide flat wire provides more surface area.

For the purpose of DC grounding only, any large round wire will do and you are simply connecting it from the ARB to your vehicle frame. You will likely find that to get a good ground, you need to remove some of the powder coating both at the point of the ground strap and at the point the antenna is mounted. This can be tested using a simple continuity meter to check for continuity between the antenna mount and the vehicle frame or battery negative connection (which is also grounded to your vehicle frame).

But for RF grounding and better image (ground) plane and therefore better antenna performance, a wide flat strap is better.

But before we get too far into the discussion of how to best bond your vehicle, lets get back to the basics.

What happens when you start the truck (to produce the noise) and then disconnect the antenna from the CB radio? Does the noise remain or does it disappear?

Next, what are the results of the continuity check on the antenna? If there is a ground short in the coax, then that needs to be resolved first to avoid damage to your radio.

And finally, here is the only pix I can find of a ground strap. Again, any round large gauge wire will do in a pinch, but a wide flat wire is best to carry RF in addition to DC ground. Ignore the clamp in the foreground of the picture, the strap is behind it. Also in a pinch, the shielding from coax can be flattened and used as a ground strap - just be careful when cutting the outer insulation that you don't cut the shielding also. You'll need to crimp AND solder a ring terminal to the end of the strap. Again, don't get too far into this until we figure out the other issues above and isolate the problem(s).

 

[MJM]

More info

Sorry for the delay - I'm having a tough time finding a picture and I'm connecting from my mobile phone so I'm a bit limited without my computer and files.

Basically, you're looking for a wide flat braided wire. The reason for the wide flat rather than typical round wire is that RF flows on the surface of the wire rather than through the wire and a wide flat wire provides more surface area.

For the purpose of DC grounding only, any large round wire will do and you are simply connecting it from the ARB to your vehicle frame. You will likely find that to get a good ground, you need to remove some of the powder coating both at the point of the ground strap and at the point the antenna is mounted. This can be tested using a simple continuity meter to check for continuity between the antenna mount and the vehicle frame or battery negative connection (which is also grounded to your vehicle frame).

But for RF grounding and better image (ground) plane and therefore better antenna performance, a wide flat strap is better.

But before we get too far into the discussion of how to best bond your vehicle, lets get back to the basics.

What happens when you start the truck (to produce the noise) and then disconnect the antenna from the CB radio? Does the noise remain or does it disappear?

Next, what are the results of the continuity check on the antenna? If there is a ground short in the coax, then that needs to be resolved first to avoid damage to your radio.

And finally, here is the only pix I can find of a ground strap. Again, any round large gauge wire will do in a pinch, but a wide flat wire is best to carry RF in addition to DC ground. Ignore the clamp in the foreground of the picture, the strap is behind it. Also in a pinch, the shielding from coax can be flattened and used as a ground strap - just be careful when cutting the outer insulation that you don't cut the shielding also. You'll need to crimp AND solder a ring terminal to the end of the strap. Again, don't get too far into this until we figure out the other issues above and isolate the problem(s).

When I went to test I could hear the carb cooling fan running in CB with the truck turned off. No antenna hooked up I could not hear the noise at all. With the antenna hooked up I could hear everything. I attached the ground strap to the base of the antenna and then to a hole on the body under the hood. The SWR reading did change a little but the noise was still there. I then connected the ground to the battery neg. terminal and the radio was dead I could not even get the RF/Squelch to make it create some noise. I then hooked the ground back to the body and could hear some trucker’s way off in the distance. With the truck started I could still hear the whine that followed the RPMs I can not confirm that the radio even works now.
Could I have ruined the radio? I have never transmitted with no antenna.

How do I test the antenna or what should my next step be.

Great thread and thanks

 

[Miescha]

When I went to test I could hear the carb cooling fan running in CB with the truck turned off. No antenna hooked up I could not hear the noise at all. With the antenna hooked up I could hear everything.

Lets start here. It seems clear that the source of your noise is via the coax antenna cable and not the power supply. It may not seem like much, but this has narrowed the source of the problem considerably. If there is any way for you to get some quality coax (not the stuff you found at Radio Shack), this would probably be the quickest and easiest way to solve the noise problem. All the other procedures for DC and RF grounding are still very useful and helpful, but you may be able to cut out most of the noise with quality shielded coax. Of course, it still requires that you properly attach the connector at the end and that requires some soldering skill - though not much. When/if you do run new coax, be VERY careful to make certain you do not nick or otherwise damage the outer insulation - this will create an easy source for noise to enter your system. If you keep the old coax, check for nicks or cuts in the insulation.

At the very least, we now know that the source of your noise is via the antenna side - either the coax, the mount, or the antenna itself. Given that the antenna is new and of reliable quality, I suggest we focus on the mount and coax.

I'll continue on the assumption that you will NOT be changing the coax - b/c all these items are still good to do even with new higher quality coax.

I attached the ground strap to the base of the antenna and then to a hole on the body under the hood. The SWR reading did change a little but the noise was still there.

Actually, you need to connect the ground strap to the frame - not the body. Basically, look for an attachment point on one or both of the two forward frame rails (where your ARB mounts). But for the high quality ARB powder coating on your bumper, it would already have an excellent DC and RF ground. You will almost certainly need to remove some of the powder coating to get a good ground. You can attack this later, for now, lets focus on the coax as that is likely the bigger problem.

I then connected the ground to the battery neg. terminal and the radio was dead I could not even get the RF/Squelch to make it create some noise. I then hooked the ground back to the body and could hear some trucker’s way off in the distance. With the truck started I could still hear the whine that followed the RPMs I can not confirm that the radio even works now.
Could I have ruined the radio? I have never transmitted with no antenna.

Lets get this out of the way also. Making the connection to the body or the battery is really the same thing (remember, your battery negative post is connected to the trucks frame - follow the wires if you have any doubts or read the many posts on dual battery systems). If you were later able to hear trucker's way off in the distance, your radio is still working - don't panic.

How do I test the antenna or what should my next step be.

Lets start with a clear plan of attack.

1. Visually check your coax for any damage done during the install (most commonly when routing it through the firewall or other bare metal surfaces). Even a deep scrap can create problems. If you find damage, you will almost certainly need to replace the coax (and I recommend this anyway so you can move to better quality coax, but I'll stop beating that dead horse ).
2. Once you know the coax is not damaged (and be sure to check it even if you do replace it), you'll want to check for ground short as a further way to test for unseen damage, but mostly to test that your attachment of the end connector was done properly (whether soldered or crimped). Rather than reinvent the wheel, I'll simply attach the following link to the Firestick site that explains how to test. Testing Continuity -- 1996 Firestik&#174 Antenna Company Of course, you'll need an ohm meter or multi-meter to perform the continuity tests and you'll need to know the basics of how to perform the test. If you don't have a meter or don't know how to use one, you'll be stuck here until you do. Post up your location and maybe someone local can help you out with a meter or even how to test your system.
3. Post up once you have tested and confirmed proper continuity of the coax/antenna system and quality/integrity of the coax. If all this tests properly, then the only thing left is to continue with bonding.

While you are at the Firestick site, it may be helpful to read through their FAQ section - most of the stuff is pretty basic and will help you understand the challenges involved with getting your system setup correctly.

In particular for your problems, look at this section on how to attach the common connector. Coax Cable Processing with Firestik® Connectors
Presumably, you are using some form of 259 connector which requires care in folding back the braided shield (this is key to good grounding) and requires proper soldering of the center pin.

Here is some more info on why you need to carefully check the coax you used and, preferably, replace it with quality coax (I know I said I would stop beating this horse, but I'm pretty sure this is the most likely source of your trouble). Coax number flaw

I'll wait to hear back on the results of testing and then we can proceed from there.

Hang in there!

 

[MJM]

Time is running out

I think my best bet would be to stop at a truck stop on my way out of town buy a new cable and stud mount and do the install in the parking lot.

Back to the ground,
If I run the ground strap from the bumper to the frame I can assume the stud mount will ground it to the bumper?

 

[Miescha]

I think my best bet would be to stop at a truck stop on my way out of town buy a new cable and stud mount and do the install in the parking lot.

I certainly understand the lack of time issue. However, if you just buy a new coax (not sure you even need a new stud mount) you can't be assured of finding quality at a truck stop (you might, I just don't know). I guess all you can do is read the links above and try to find something that matches the higher quality stuff Firestick mentions.

The bigger issue is that a parking lot install will still need to be checked for ground short/continuity issues. So you'll need a meter and the knowledge of what to do and how. Also, you'll be soldering in the parking lot (so you'll need a soldering gun and a transformer to power it from your truck).

If you have checked your current installed coax and find no nicks or cuts, maybe just keep it in place for now given the tight time constraints and plan on changing it later.

Use the time now to check the installation of your connectors (can you post pics of the installed connectors?). If the end connectors at the antenna and radio are not installed correctly, you will have many problems resulting in everything from noise to power reception to poor transmission.

Back to the ground,
If I run the ground strap from the bumper to the frame I can assume the stud mount will ground it to the bumper?

No - the bigger issue is removing the paint at the point the antenna is mounted. In my installation on my '96 FJ80 I also used the upper mounting tabs of my front ARB bumper. Initially, I had no DC ground at all according to my meter and that was causing SWR greater than 3 across the spectrum that I could not correct. I initially used a 10g stranded wire to the antenna mount to confirm that this would correct the problem - it did. I then removed my ARB (this was not easy) with the plan of removing all the powder coating at the point where the ARB mounts to the front frame rails. I found that there was not all that much coating on the inner side of the mounts, but I wire brushed it all anyway and reinstalled the ARB. I then removed the powder coating on the top of the mounting tab where my antenna would go (I removed as little as I could and still have the antenna mount on bare metal). I then confirmed with my test meter that I had DC ground continuity between the mounting tab and the truck frame rails and also the truck battery negative terminal. I then mounted the antenna and checked the SWR and found it at 1.3 mid-spectrum before any tuning. With tuning, I was able to get to 1.1:1 mid spectrum and 1.3 at the ends.

I did install two 1" wide ground straps from the ARB - one to each of the front frame rails. My thinking was these would help with RF grounding as I wasn't sure RF would flow across the surface of the ARB given the powder coating. I don't think this is necessary so I plan to remove them and check for any negative results.

So . . . my advice to you (in the interest of saving you time) is that you remove a small amount of paint on the mounting tab where your antenna will be mounted (mark the antenna stud before removing it and then carefully remove the paint at that location). Depending on the setup you have, you may need to remove paint on both the top and bottom of the mounting tab. Again, remove only the amount necessary to get a good ground in order to minimize future surface rusting. I added some dielectric grease to help improve the connection while hoping to prevent rust - but I have no idea if this will help and I've only had it mounted for about one year so no rust yet.

Then, test for continuity from the newly bared metal on the tab to the truck frame rails and also to the battery negative terminal. If there is continuity, then you can assume (at least for now) that your ARB has enough bare metal at the attachment point that you are getting DC grounding and probably RF grounding also.

If you have continuity, then reinstall the antenna mount and antenna and check your SWR. Hopefully, you'll have low enough SWR and less noise.

Either way, you need to check continuity / ground shorts in your coax (per the Firestick links above). Given the noise you've been having, I still recommend that at a minimum you remove your end connectors and double check that you have the shielding properly peeled back and that the center wire is properly exposed (again, see the Firestick links above). Then reinstall the connectors per the links and make sure the center wire is properly soldered per the links above.

I use the pre-packaged Firestick Fire Ring coax so I only have to worry about this at the radio end.

 

[MJM]

Fixed Problem

Holy revised thread but I wanted to let everyone know that the problem is now fixed. It turned out that the spark plugs I put in last year were non-resistor. Even though the parts guy said they were. This year I replaced the plugs with OEM resistor plugs and there is no interference and I was able to remove the extra grounding strips.
Make sure your spark plugs are in fact the resistor type do not trust the NAPA guy.
MJM