CB installation *Tune your antenna!*

[garyft]

Well, I just got (finally) finished getting my CB install done. I recently bought and installed this kit from Sierra: http://www.sierra-mc.com/proddetail.asp?...BRA-IMCKIT

I have to say I'm happy with the performance, but I ran into some issues along the way and thought I'd pass some information along. First and foremost, I learned that a CB antenna is NOT a plug-and-play installation. The handheld CB came with a little 8 inch rubber antenna, but I thought that since I already had a CB antenna on the bike I'd just hook it up to that and be able to get a little better reception/transmission distance. I added a splitter from Sierra as well: http://www.sierra-mc.com/proddetail.asp?prod=SIE-CP-27 as well as an adapter to connect a standard PL-259 CB antenna connector to the BNC connector on the CB. This adapter is available from Cobra: http://www.cobra.com/products/handheld-c...ndheld-cbs.

I got everything installed and took off that weekend with a buddy for a 1,000 mile round trip camping trip. He was on his GL1800 with factory CB. At our first stop, he said that he could just barely hear me when were within 100 yards and outside that he couldn't hear me at all. Well, I had brought little rubber antenna that came with the radio with me and put that on. Instant difference, he said it was like night and day. However, I know the range on this antenna is limited to 1-2 miles.

After we got back, I started checking and learned a lot that I didn't know. If you have never dealt with tuning a CB antenna and don't know what SWR stands for (like me) I STRONGLY suggest that you head over to Firestik Antenna's web site and read their tech help section.

http://www.firestik.com/Tech_Docs.htm

They have a great deal of information and I quickly learned that I could have easily burned out the transmitter on my new radio with the way I had it set up.

I went and got an SWR meter and hooked it up with my stock antenna and found that none of the RF signal being generated by the CB was actually getting put out through the antenna.

I got to work on the antenna and found that there was no continuity between the center conductor of the coax cable and the antenna base. Well, being too cheap (and broke) to go buy a new antenna, I pulled the base apart after a great deal of trouble and found a broken solder connection in the antenna base. I got that fixed, hooked everything back up and checked the SWR again, still no signal getting out. The SWR was off the scale. I read a little more and found that the recommendation is to tune the antenna without the splitter in place first, so I hooked that up. Even sitting in my garage I now had an SWR below 2. Next, I looked to the splitter and found that in all my assembling/disassembling I had broken an internal connector in the splitter. Got that fixed and took the bike out to an open area and checked it with the meter and it looked great, less than 1.3 SWR across the board. Put the splitter in and used it's internal tuner to get it matched to the antenna setup and radio, now everything works great.

What I learned:

TUNE YOUR ANTENNA! Unless you like replacing CB's.

Make sure the antenna base is well grounded. Not the actual antenna, but the mount. If necessary, run a ground wire to the chassis (I did just to make sure).

[admin]

I had to cut off about 6" of the upper section of my CB antenna before I got a decent SWR (standing wave ratio) Seems contradictory but it's a fact that the CB worked better with a shorter antenna than a long one.

[garyft]

It's all about the radio and wiring and every installation is different. A lot of people don't realize that there is a huge difference between an antenna only used to receive a signal and one that is used to transmit.

[SIR tricky]

I had to cut off about 6" of the upper section of my CB antenna before I got a decent SWR (standing wave ratio) Seems contradictory but it's a fact that the CB worked better with a shorter antenna than a long one.

I dont need to transmit more than 1/2 a mile, if the person I am talking to is any further than that then he isnt riding with me. besides if I cut any off the antenna then it wont match the one on the other side.
One has to keep up appearances :roll:

[admin]

I bet you wouldn't be saying that if your bike quit 3/4 of a mile away from the group you're riding with.

[garyft]

Vic, that's exactly why I worked so hard on mine. Someone else made that comment to me, that I shouldn't need more range. But what if we get separated at a light and someone misses a turn, or a breakdown, etc. I like the peace of mind that I should be able to reach out 5+ miles or further.

[SIR tricky]

If one is riding in a group then one must learn the group riding rules, what did we do prior to bike to bike communication?
Always keep the person behind you in sight, even if it means stopping at a corner or a light, for them to catch up.
Many is the time I have turned off the CB because of incessant chatter amongst a group.

A CB also isnt going to be of any use if I am riding solo and I break down.

[SIR tricky]

But what if we get separated at a light and someone misses a turn,

If your that far away maybe they are trying to tell you something

[admin]

That's funny Tricky. You know I'm still amazed at the range I had when communicating with your CB. All conditions must have been right on that day but to be able to hear you and speak to you perfectly clearly at 7 kilometers was simply impressive. I'm even trying to perfect my CB a little more by installing a filter that kills all ignition and alternator noise. The unit is expensive but garanteed to work. This unit is used on border customs cars and police cars and it is a proven fact that it makes a difference in radio noise.

[detdrbuzzard]

your swr ratio should never be over 1.5:1, 1:1 is best. over 1.5:1 causes heat buildup in the tranceiver and will burnup you radio.you can either tune the coax or the antenna

[admin]

If my memory serves me correctly I believe that my SWR was 1.26 which is supposed to be darn good.

[garyft]

Vic,

Where did you get your filter and what brand/type is it?

[admin]

I got my Kenwood KLF-2 filter at Kelcom Communications but I will be returning it as I no longer need because I fixed the noise problem by repairing a bad ground.

[garyft]

Vic, you just reminded something else everyone needs to keep in mind. It is imperative that the antenna base have a good, solid ground. even though it's bolted to all metal parts, you may want to run an auxiliary ground strap to the frame. Was yours an antenna ground problem or power ground?

[admin]

It was a power ground in my case.