J&M Cb radio

  • Thread starter EarnhardtSports
  • Start date

EarnhardtSports

I installed this and the Firestick II antennae. SWR is correct. Itouch plays tunes well and intercom works well. Transmit range is less than 1/2 mile. Lots of engine noise so the people tell me during my transmissions has lots of static. Using a good headset and can hear well. I have heard some get real good range from these but I have a problem somewhere. antennae mount is grounded also. What am I missing here?
Thanks
Eddie
 
the power to the main unit must be grounded on the frame, not the battery nor a fuse box that is connected to the battery.
 
Are the wires routed inside the frame as much as possible (ie, away from the spark plug coils)?
 
Main unit is frame grounded but wires are to the OUTSIDE of frame. I figured after I heard it the wires need to be re-routed.Thanks
 
Are you using the NGP Firestik ?

Transmit range isn't going to be great, just the way it is... 1/2 mile is not terrible if you're using it for bike-to-bike comms. You still have a much better receive range typically. So much depends on outside influences you can't control. There shouldn't be static all the time, maybe sometimes. I have mine on the outside of the frame and just never took the time to reroute the antenna.
 
Mellow,
I bought this rig used and it came off another ST and the Firestick II came with it? What should I be using?
 
EarnhardtSports said:
Mellow,
I bought this rig used and it came off another ST and the Firestick II came with it? What should I be using?
Click to expand...

Well, if it's a NGP (no ground plane) antenna, there should be a yellow band around the base. A specific cable needs to be used and it has to be a specific length. NGP cable setups do not work well if the excess cable is coiled.. Also, make sure the cable doesn't have any nicks/cuts in it.

A regular antenna, will need more material - steel - to produce optimum results, some add metal plates in top boxes to attach to.
 
No yellow band around the bottom and I am going to add a bigger ground strap for the mount. I know these radios will not talk like my wing's cb but I expected more than this. Pete at bikemp3.com is supposed to be having a cruiser type cb out soon. I will re-route the wires as soon as I am comfortable removing the tupperware. Wings are no problem as I have worked on them for years but no ST in the area.
 
The J&m cb is a good cb and capable of some good range. Unfortunatly our bikes are not the best platform for cb operation. You must take special care in your setup to get good performance. Routing of wires between air box and frame helps. I used electrical loops on the screws for the airbox to hold them in place. I routed the antenna wire over the triple tree with the connector in a clip so I can test the swr without lifting the tank. Antenna wire on right side of airbox and come around the back to the left side of the bike. Make sure all grounds from your radio and any other device are at the same point. I used the seat mount bolt then a ground strap to the the negative side on the battery. Do not ground anywhere on the alum frame or near the engine. I asume you have the j&m inline noise filter on your power..

Now here is something different I learned on this forum. At the antenna base I isolated the ground and added a 9ft 12ga twisted strand wire from the ground of the antenna and routed it under the seat up and down the right and left side of the bike. I did not ground this wire. This gave me a really good swr on most channels centering on 20. Make sure with your ohm meter that your antenna wire is not shorted out in any location. and that the banjo setup on the antenna end is not reversed.

Others may have a different approach but this worked for me.
 
Roadriderg
Thanks for the info as this is what I am looking for and will try this setup...
 
Any thing is worth a try.

I just want to add to what Mellow has stated... you do not want to coil up your antenna wire. This acts as a choke and will effect performance. If you have to coil it do it in a butterly fashion not a loop.
 
Gary
I reworked some of my wireing and ran a 12 gauge 9 foot piece from antennae mount down right side of back and around left side of tank and it ended under the seat. I also ran a BIGGER ground from mount to seat hardware and then routed other wires inside of frame rails next to tank. One of the 2 grounds (I think the 9 foot wire) really lowered my SWR's so they are almost non existent. I also hooked up my POWERLET between the bars for iTouch, iPhone4S, and Garmin GPS. Thanks to your info I think I am getting close. I may try a Firestick Firefly instead of the Firestick II I now run. John Lazzaroni at J&M suggested picking up my power from the rear lights?
Thanks Man,
Eddie
 
I use the firefly 3 ft and it works great. Note; my 9 ft wire is ungrounded on the open end and grounded on the antenna ground. The antenna ground is not grounded to the frame of the bike. I get a very low swr with this setup. One of the cb gurus here came up with that setup (but I forget who, but it will come to me latter.).

I do not suggest getting your power from the brake light circuit. I used a relay triggered by a switched circuit then direct to the battery.
 
Gary,
My 9 foot wire is attached to antennae mount and the other end is OPEN. I picked up my HOT (SWITCHED) via a Tulsa Fuse box with relay coming off the red with green stripe in fuse box. So far so good but haven't talked to anyone with it yet. Will keep ya posted...
 
Gary,
What length cb coax are you running? I am running a 9 foot on the Firestick II but seems the firefly calls for 18 feet?
Thanks
Eddie
 
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