CB radios
#1
10-22-2007, 06:41 PM
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CB radios
Hello all,
I recently got 2 older cb radios from ebay, and am wondering where, in preferebly Red Deer or Calgary as I am in Olds, where they can help set them up. I bought 3 foot antennaes while in Ontario so I could use them on the drive back but could never get them to work.
I am wondering if there is an easy way to see if they are any good, or if they just need to be "tweaked"
Thank you all for any info.
Craig
I recently got 2 older cb radios from ebay, and am wondering where, in preferebly Red Deer or Calgary as I am in Olds, where they can help set them up. I bought 3 foot antennaes while in Ontario so I could use them on the drive back but could never get them to work.
I am wondering if there is an easy way to see if they are any good, or if they just need to be "tweaked"
Thank you all for any info.
Craig
#3
10-22-2007, 11:46 PM
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#4
10-23-2007, 04:39 PM
Normally when one buys CB antennas the matching length coax is included in the. package
Ie:Bottom load trunk mount coax is 18' 6" long
Twin mirror Top load antennas require about 2 lengths (co-phased) of coax about 18' long.
About the length: This is a testy subject with many engineering types. They have argued with us on many occasions regarding this matter. They say that if your system is set-up properly that the length of the coax is irrelevant. We agree! However, mobile installations have so many variables that a perfect set-up is the exception, not the rule. One guy has a pick-up and another has a fiberglass motorhome. One wants the antenna on the bumper, another on the hood and a third on the roof. Few people want to drill holes in their vehicle so quality grounds are always a consideration. Because of the imperfect world, we almost always recommend 18' (5.5m) when our products are used. We do so with good reason too! At 18' the voltage curve has dropped back to the zero voltage point where the cable meets the antenna which reduces the reactance within the cable itself (a null cable if you would). It has been our experience that if the antenna location makes it somewhat out of sync with its surroundings, cable lengths that are not multiples of our 18' suggestion adds to the problem. To that, our complaining experts say, "Then the antenna should be moved!" to which we say, "You tell the guy with the $30,000 vehicle that he must drill a hole in his roof so he can use a 9' cable". We solve problems in the best way we can given the boundaries that the customer establishes.
On that note, when you have 18' of coax going to a radio that is only 8' away, what should you do with the other 10'? We recommend that you serpentine it like a skein of yarn so that it is 10-14" long and tie it in the center with a wire tie then tuck it away. Do not roll it up in a tight circle as this can cause it to act like an RF choke, which often times will cause system problems.
Ie:Bottom load trunk mount coax is 18' 6" long
Twin mirror Top load antennas require about 2 lengths (co-phased) of coax about 18' long.
About the length: This is a testy subject with many engineering types. They have argued with us on many occasions regarding this matter. They say that if your system is set-up properly that the length of the coax is irrelevant. We agree! However, mobile installations have so many variables that a perfect set-up is the exception, not the rule. One guy has a pick-up and another has a fiberglass motorhome. One wants the antenna on the bumper, another on the hood and a third on the roof. Few people want to drill holes in their vehicle so quality grounds are always a consideration. Because of the imperfect world, we almost always recommend 18' (5.5m) when our products are used. We do so with good reason too! At 18' the voltage curve has dropped back to the zero voltage point where the cable meets the antenna which reduces the reactance within the cable itself (a null cable if you would). It has been our experience that if the antenna location makes it somewhat out of sync with its surroundings, cable lengths that are not multiples of our 18' suggestion adds to the problem. To that, our complaining experts say, "Then the antenna should be moved!" to which we say, "You tell the guy with the $30,000 vehicle that he must drill a hole in his roof so he can use a 9' cable". We solve problems in the best way we can given the boundaries that the customer establishes.
On that note, when you have 18' of coax going to a radio that is only 8' away, what should you do with the other 10'? We recommend that you serpentine it like a skein of yarn so that it is 10-14" long and tie it in the center with a wire tie then tuck it away. Do not roll it up in a tight circle as this can cause it to act like an RF choke, which often times will cause system problems.
Last edited by Mil1ion; 10-23-2007 at 04:42 PM.
#5
10-24-2007, 01:17 PM
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