| Author |
Message |
    
KField4742
| | Posted on Thursday, September 27, 2001 - 1:17 pm: | 
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I have a Galaxy 949 installed in an aluminum trailer. I have a Wilson 200watt 4' silver loaded antenna, with a 20' coax to the antenna.
the CB is mounted to a wooden cabinet, not grounded, and the ground wire on the Wilson antenna is not connected either.
I don't seem to be transmitting very far.
Do I need to ground this CB to the chassis?
Will connecting the antenna ground do the job?
Do I need to ground everything to the chassis?
Ken |
Harpoonman
| | Posted on Monday, October 01, 2001 - 10:37 am: |
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Ken,
Here is my input, for what it may be worth(!)
First, make sure that your coax is working properly and that it has no short in it. If you get a very high SWR (like 3.0:1 or more), you may have a problem with the coax. This would cause you to "get out" poorly and also to receive poorly.
Second, unless your antenna is specifically designed to work without a ground, it needs to have a good earth ground which the wooden cabinet is not likely to supply. Use at least a medium gage copper wire from the mounting bracket of the antenna and run it outside to a copper rod is at least 3-4 feet long (8-9 feet would be best, I think), and drive the rod into the ground. Then connect the other end of the copper wire. In a pinch, you could also run the copper wire to a COLD WATER PIPE!
Third, be sure to properly tune the antenna by connecting an SWR meter between the radio and antenna. You want to tune for the lowest standing wave ratio (SWR) that you can for a given frequency (tune while keying the mic). If you use all 40 of the regular CB channels, tune on channel 20. If you're like me and talk on channel 36 and up (SSB) tune around channel 40.
Try to get a ratio of 2.0:1 or less, although I am not happy unless my SWR is no more than 1.5:1. Don't tune the antenna until you have it well grounded.
Finally, and this may be the most important factor, it sounds like you are using your antenna INSIDE your trailer. The metal of the trailer itself may be severely reducing your ability to transmit and receive effectively. After you are sure that the coax and its connections is good, that the antenna is properly grounded and that it is tuned for the lowest SWR you can achieve, try moving the antenna outside somewhere on top of your trailer, if you can.
In fact, if this is possible, I suggest getting one of the simple vertical base antennas like the Solarcon A99 or IMAX 2000 (I'm assuming that the Wilson antenna you describe is a mobile antenna), and mounting it on a sturdy support pole outside the trailer with the base of the antenna at least 18 feet above the surrounding ground. If you get much higher than this you may want to use some guy wires for additonal support of the antenna.
Hope this helps,
Harpoonman |
Taz
| | Posted on Tuesday, October 23, 2001 - 3:14 pm: |
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swr does not affect your recive, just transmit but your coax can affect your recive |
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