cobra 75 messing with my electronics
JK Enthusiast
Joined: Oct 2012
Posts: 158
Likes: 0
From: Tustin, CA
You will see a couple off cars with cb antennas outside(employees). You can see it from the street, and they have a sign outside saying "cb shop" or something similar.
Good guys, good service.
Besides selling, equipment they do repairs, upgrades, installs and tune up's
JK Enthusiast
Joined: Sep 2011
Posts: 315
Likes: 0
From: Pomona, Ca
Yes, it's off Milliken. In the industrial buildings next to the truck stop.
You will see a couple off cars with cb antennas outside(employees). You can see it from the street, and they have a sign outside saying "cb shop" or something similar.
Good guys, good service.
Besides selling, equipment they do repairs, upgrades, installs and tune up's
Yup! Found it and we fixed it! Thanks for the heads up..
JK Enthusiast
Joined: Sep 2011
Posts: 315
Likes: 0
From: Pomona, Ca
Yes, it's off Milliken. In the industrial buildings next to the truck stop.
You will see a couple off cars with cb antennas outside(employees). You can see it from the street, and they have a sign outside saying "cb shop" or something similar.
Good guys, good service.
Besides selling, equipment they do repairs, upgrades, installs and tune up's
I actually bought the mount at the truck stop not the cb shop.. Didn't know there was one down the st. Good thing I found it!
JK Newbie
Joined: Jun 2012
Posts: 89
Likes: 0
From: Cotton Valley, St Croix, USVI
Ok this has officially been taken to a whole new level. I was driving tonight on a pretty empty highway and when I went to pass an 18 wheeler, BOOM! I lost my dash, fogs turned off, radio gone, wiper on, you get the idea... My cb was off! What signal did Chrysler send out to tell our jeeps to reject any mods possible?! It's bad enough we can't tune 2011+ but please let us enjoy our rigs! I'm bonding everything tomorrow an crossing my fingers otherwise starting price for my whole cb set up is 100 bucks..
Think about it - your antenna system is supposed to be an efficient way for RF to get IN as well as OUT of your vehicle (which by itself is a fairly efficient Faraday cage). If you've got a faulty antenna system, there's going to be RF charging about on the INSIDE of your Faraday cage - where all of Jeep's sensitive electronics are.
The suggestions about ferrites are good ones. You may need quite a few, as someone else noted. If you're going to make a choke out of a coil of coax, you can't just coil it up any old way; it has to be coiled, like on a spool or form. That takes up space, but it's effective and less expensive than lots of ferrite. Do remember that such chokes must be AT THE ANTENNA FEEDPOINT, not a couple of feet away. That means if you're going to install one, it has to be OUTSIDE the vehicle right at the antenna connector. It's also a good idea to have one at the radio end of the feedline.
Investigate the route your feedline takes from antenna to radio. If it is routed parallel to vehicle wiring, EMI is likely. RF feedlines should always pass vehicle wiring looms at 90-degree angles, i.e., perpendicular to the direction of the loom. Yes, it takes more feedline. But it helps.
Get better coax. Those seperate-mic-and-box CBs are convenient, but if all of the RF-generating circuitry is in the head/mic (and it might not be; I have no idea), and the manufacturer used crappy, poorly-shielded coax for that coiled cord, you're simply going to be in for problems. I have no advice to help you. However, if you're not using one of those but instead a traditional shiny-box radio, consider buying coax that's worth a damn. The stuff you get at the truck stop, Radio Shack and CB shops (online and brick-and-mortar) is 9 times out of 10 utter crap. Cheap coax is poorly-shielded, which lets RF get in and out of the feedline. So replace it.
Now that you've replaced your feedline you can make your own vehicle bonding straps. Just strip off the braid from the old coax.
Here's what you do: Go to DX Engineering and buy some good RG-8X coax. (If you don't want to use my link, look for Belden or JSC coax with the solid-core - NOT foam-core - dialectric.) Remove the crap coax that came with your CB, cut off the connectors and pull the braid off the coax. Recycle the other stuff. Cut the braid in lengths you need. Poke a hole in each end with a philips-head screwdriver. Tin those ends (this is a far superior method, physically and electrically, than crimping on rings). Boom. Ground straps. Now install your new, high-quality coax, properly install good silver-teflon PL-259 connectors with the correct reducers for your cable. See here for a good tutorial on properly installing connectors.
In sum, I suspect the problem is in your feedline before the bonding. Do definitely inspect and improve your vehicle bonding, but first replace your feedline with quality coax while paying attention to the path the coax takes through the vehicle. Install enough feedline to make common-mode chokes at the radio and antenna ends of the installation. Properly ground your radio with a DC ground (to the battery). Properly bond your vehicle together with braided straps. That should solve the problem.
JK Super Freak
Joined: Nov 2010
Posts: 1,307
Likes: 0
From: Alb., NM
This is a classic case of RF overload. I suspect the trucker was using an illegal amplifier. As you went to pass him, he keyed up with 500 watts or something, and it got into your onboard electronics. That's not really your fault, beyond you installed an antenna.
Think about it - your antenna system is supposed to be an efficient way for RF to get IN as well as OUT of your vehicle (which by itself is a fairly efficient Faraday cage). If you've got a faulty antenna system, there's going to be RF charging about on the INSIDE of your Faraday cage - where all of Jeep's sensitive electronics are.
The suggestions about ferrites are good ones. You may need quite a few, as someone else noted. If you're going to make a choke out of a coil of coax, you can't just coil it up any old way; it has to be coiled, like on a spool or form. That takes up space, but it's effective and less expensive than lots of ferrite. Do remember that such chokes must be AT THE ANTENNA FEEDPOINT, not a couple of feet away. That means if you're going to install one, it has to be OUTSIDE the vehicle right at the antenna connector. It's also a good idea to have one at the radio end of the feedline.
Investigate the route your feedline takes from antenna to radio. If it is routed parallel to vehicle wiring, EMI is likely. RF feedlines should always pass vehicle wiring looms at 90-degree angles, i.e., perpendicular to the direction of the loom. Yes, it takes more feedline. But it helps.
Get better coax. Those seperate-mic-and-box CBs are convenient, but if all of the RF-generating circuitry is in the head/mic (and it might not be; I have no idea), and the manufacturer used crappy, poorly-shielded coax for that coiled cord, you're simply going to be in for problems. I have no advice to help you. However, if you're not using one of those but instead a traditional shiny-box radio, consider buying coax that's worth a damn. The stuff you get at the truck stop, Radio Shack and CB shops (online and brick-and-mortar) is 9 times out of 10 utter crap. Cheap coax is poorly-shielded, which lets RF get in and out of the feedline. So replace it.
Now that you've replaced your feedline you can make your own vehicle bonding straps. Just strip off the braid from the old coax. Here's what you do: Go to DX Engineering and buy some good RG-8X coax. (If you don't want to use my link, look for Belden or JSC coax with the solid-core - NOT foam-core - dialectric.) Remove the crap coax that came with your CB, cut off the connectors and pull the braid off the coax. Recycle the other stuff. Cut the braid in lengths you need. Poke a hole in each end with a philips-head screwdriver. Tin those ends (this is a far superior method, physically and electrically, than crimping on rings). Boom. Ground straps.
Now install your new, high-quality coax, properly install good silver-teflon PL-259 connectors with the correct reducers for your cable. See here for a good tutorial on properly installing connectors.
In sum, I suspect the problem is in your feedline before the bonding. Do definitely inspect and improve your vehicle bonding, but first replace your feedline with quality coax while paying attention to the path the coax takes through the vehicle. Install enough feedline to make common-mode chokes at the radio and antenna ends of the installation. Properly ground your radio with a DC ground (to the battery). Properly bond your vehicle together with braided straps. That should solve the problem.
Think about it - your antenna system is supposed to be an efficient way for RF to get IN as well as OUT of your vehicle (which by itself is a fairly efficient Faraday cage). If you've got a faulty antenna system, there's going to be RF charging about on the INSIDE of your Faraday cage - where all of Jeep's sensitive electronics are.
The suggestions about ferrites are good ones. You may need quite a few, as someone else noted. If you're going to make a choke out of a coil of coax, you can't just coil it up any old way; it has to be coiled, like on a spool or form. That takes up space, but it's effective and less expensive than lots of ferrite. Do remember that such chokes must be AT THE ANTENNA FEEDPOINT, not a couple of feet away. That means if you're going to install one, it has to be OUTSIDE the vehicle right at the antenna connector. It's also a good idea to have one at the radio end of the feedline.
Investigate the route your feedline takes from antenna to radio. If it is routed parallel to vehicle wiring, EMI is likely. RF feedlines should always pass vehicle wiring looms at 90-degree angles, i.e., perpendicular to the direction of the loom. Yes, it takes more feedline. But it helps.
Get better coax. Those seperate-mic-and-box CBs are convenient, but if all of the RF-generating circuitry is in the head/mic (and it might not be; I have no idea), and the manufacturer used crappy, poorly-shielded coax for that coiled cord, you're simply going to be in for problems. I have no advice to help you. However, if you're not using one of those but instead a traditional shiny-box radio, consider buying coax that's worth a damn. The stuff you get at the truck stop, Radio Shack and CB shops (online and brick-and-mortar) is 9 times out of 10 utter crap. Cheap coax is poorly-shielded, which lets RF get in and out of the feedline. So replace it.
Now that you've replaced your feedline you can make your own vehicle bonding straps. Just strip off the braid from the old coax.
Here's what you do: Go to DX Engineering and buy some good RG-8X coax. (If you don't want to use my link, look for Belden or JSC coax with the solid-core - NOT foam-core - dialectric.) Remove the crap coax that came with your CB, cut off the connectors and pull the braid off the coax. Recycle the other stuff. Cut the braid in lengths you need. Poke a hole in each end with a philips-head screwdriver. Tin those ends (this is a far superior method, physically and electrically, than crimping on rings). Boom. Ground straps. Now install your new, high-quality coax, properly install good silver-teflon PL-259 connectors with the correct reducers for your cable. See here for a good tutorial on properly installing connectors.
In sum, I suspect the problem is in your feedline before the bonding. Do definitely inspect and improve your vehicle bonding, but first replace your feedline with quality coax while paying attention to the path the coax takes through the vehicle. Install enough feedline to make common-mode chokes at the radio and antenna ends of the installation. Properly ground your radio with a DC ground (to the battery). Properly bond your vehicle together with braided straps. That should solve the problem.
suspect they will have to do several of this items (good coax, bonding, RF chokes -mix 31 beads) to solve the RFI monsters.
usually isn't solved by one item... but your starting point with good Coax is a good one.
here's hoping the RF monsters lose the war.
Thread Starter
JK Super Freak
Joined: Oct 2011
Posts: 1,384
Likes: 0
From: North Jersey
Update
update: so after rerouting the coax away from all other wiring and cleaning up all connections with no luck, I finally figured it out tonight. the trick is that I need to run my rear defroster in order for the cb to transmit without any ill affects. go figure.. so the defroster has been interfering with the transmissions when it was off, but when on its fine. i don't get it but at this point, i don't care.. I'm just happy i can use my cb again. oh and it also works when i disconnect the defroster completely but its winter and i use it daily so that isn't an option right now.
Thread Starter
JK Super Freak
Joined: Oct 2011
Posts: 1,384
Likes: 0
From: North Jersey
Definitely will do. Just wanted it to be tolerable for interstate driving in the mean time. I bet once I get my soft top back on in April, ill be fine. But yes, I do want it done the right way via troubleshooting.