| Author | Message | ||
     Blake Luse (Muddyrover) Senior Member Username: Muddyrover Post Number: 932 Registered: 02-2002 |
I went to my local cb shop and asked him to check my swr. The generic antenna that I had was reading off the graph and so did every other antenna that he put on except the no ground antenna that is on there. The antenna is on an ARB bumper in the upper passenger cb mount. What kind of antenna's have yall been able to use? This one works but I don't know how storng it is and I'd like a good one up there. | ||
| Paul D. Morgan (V22guy) Dweb Lounge Member Username: V22guy Post Number: 1774 Registered: 02-2002 |
Blake, It might not be the antenna, but rather the mounting. From the K40 antenna FAQ: What are some common reasons for high SWR? #1Insufficient ground plane #2Coax problems - Improper type, incorrect length, low quality, or damage #3Poor installation location #4Antenna not tuned properly to the vehicle I bring this because I had a dead short in my coax and the proper location of that plastic washer is critical for a proper ground. Check out: http://www.k40.com/Technical/antennafaq-2.html and while you are at it, check out: http://www.firestik.com/Tech_Docs.htm FWIW Blake, I have a 4' K40 on the Pig. Good Luck. | ||
| Blake Luse (Muddyrover) Senior Member Username: Muddyrover Post Number: 933 Registered: 02-2002 |
The guy put on about 4 different antennas including a wilson "silver load?? something" and he said that all of them were acting as if they had no ground. I've seen K40's on disco's with arb bumpers and was looking for the K40 actually. The thing that confused me was that I thought you had to remove the top cover and adjust the tip to change swr. He didn't remove it and do anything up there. My cb works fine, and I've been talking to some truckers that say it sounds good. I'm just thinking that since I don't have a big named antenna and a "no ground" antenna at that, that I'm losing performance and especially distance. Thanks Paul for the websites I'm gonna read up. | ||
| Jay Hobbs (Jayxd) Member Username: Jayxd Post Number: 162 Registered: 03-2002 |
Surely the guy at the CB shop knows how to use his SWR meter. I bought one from Radio Shack and plugged it all in, didn't read the directions very well, and spent about 20 minutes getting very frustrated. Then I figured out I needed to calibrate the SWR meter, once that was done the adjustments I made actually worked. I too thought the only way to adjust the antenna was to make it longer, or shorter, as needed at the tip. | ||
| Joey (Joey4420) Member Username: Joey4420 Post Number: 127 Registered: 04-2003 |
SWR can also be drastically effected by having your coax (X) crossing over itself. You say that you have the anntena mounted to the ARB bumper, do you have good ground on the bumper and at the mounting point? Easily checked via a multimeter. If yes, check coax. If no, you need to run a good known ground up to the mounting point. | ||
| Reed Cotton (Reedcotton) Senior Member Username: Reedcotton Post Number: 262 Registered: 01-2003 |
As been said before, check the coax, then check ALL the grounds between the antenna and the radio. Dirty or loose connections are also bad. You may want to add some additional grounds also (can't hurt). Then get an SWR meter at Radio Shack, per Jay, read the instructions, and you should be able to sort it out. -Reed | ||
| Greg (Gparrish) Senior Member Username: Gparrish Post Number: 1318 Registered: 04-2002 |
Check the plastic washer in your antenna stud to make sure it's in the proper location. Check the coax and connections for proper continuity. Using your multi meter, maker sure the wire is not broken, or a connector loose. Check for ground on the bumper. Should be grounded to the frame, but you never know. Check for dirt/paint/debris under/around the mounting stud. Should make ground, but sometimes paint can prevent it. You may have to add a grounding strap. Most of the tunable fiberglass antennas have an adjusting tip at the top. If it's a steel whip, you have to trim the whip itself to adjust. Some of the cheaper fiberglass antennas have to be trimmed under the rubber cap to adjust them. Buy the SWR meter at radio shack for $25. It's a good investment. I've used mine numerous times. Also, make sure your radio is working properly. An SWR meter isn't going to read properly if the radio is not sending a proper signal through it. Good luck. | ||
| Greg (Gparrish) Senior Member Username: Gparrish Post Number: 1319 Registered: 04-2002 |
Oh yes, double check your coax length. Too short or too long can make a difference on SWR. I had a 3' K-40 on a rear door antenna bracket and couldn't get it below a 2 on the SWR reading. Ended up switching to a 4' Wilson Flex antenna and dropped down to a bracket on the spare tire. Trimmed 2' out of my antenna wire, and ended up with an SWR reading just a hair above zero now. | ||
| Will Cupp (W_cupp) New Member Username: W_cupp Post Number: 12 Registered: 07-2003 |
I have a Galaxy CB radio with the hi and Low bands aswell as the AM and FM Freq. I had a Wilson 1000 ant., but I change to a fiberglass because I did not like the whip. Ever since the FM band has not worked. Does the FM band not work with fiberglass or is something not working? | ||
| Al Oliveira (Offroaddisco) Senior Member Username: Offroaddisco Post Number: 1436 Registered: 04-2002 |
Everyone here already gave good things to check for a bad SWR reading. But an NGP (1/2 wave) antenna isn't all that bad. If it's giving you a low SWR then you're okay. You can get good (low) SWR on a bumper but it's not an ideal location to mount your antenna. But then in our application it's okay given the options. Will, When you say you have both AM and FM on your CB are you in the US or AU? The US only has AM CB. If you're in AU then your FM CB I think is like our GMRS and that's a different animal since it's in the 462mhz range. While (US) CB is a longer frequency. Either way fiberglass or wire shouldn't make a difference. But since you're talking Galaxy I'm thinking you're talking about SSB (USB/LSB)? In that case that's still pre 70's era AM technology. Unless Glalaxy makes UHF radios for other markets. Here they're only CB (27mhz). |
