Cobra 29ltd

Don't replace it yet. You will get some good replies here. 29's are great radio's

 

Can you give more info? What is or is not happening?

 

"I am having swr and reception issues"

One leads to the other. As M said provide precise specific info on your entire antenna system and pics would be very useful.

 

I have more trust ina 29 or 25 LTD Classic than any other radio, ther bomb proof, a single antenna and a good piece of coax will do a lot to help, I spent a small fortune on antennas and my local shop turned me onto what a good coax will do, really suprised me what a difference "GOOD" coax makes.

 

Have you ever had the SWR checked with a meter other than the one on the radio?If you are driving a truck with a fiberglass body and you are using the antennas they have you could get a bad match also .You would need a no ground plane antenna If your truck has a metal body and there is a lot of rust that will throw off your SWR. Your coax might not be long enough. there is a lot of things to consider but don't toss that radio Have it checked to see if it is the problem . If it isn't than its either your coax or antenna and the connectors.

 

If its a single antenna, coax length is absolutely meaningless. If its cophased, the coax should be cut to the length to match the wavelength of the antennae. If they are 1/2 antennae, it would be 14.4 feet of RG59 on both sides.

 

you are right but the length of coax needed for a single antenna is 17" which is 1/2 wave length.unless you purchase your coax with no connectors then you can cut it to whatever length you needbut remember that in order to get a perfect match you need50 ohms from the radio,50 ohms from the coax and 50 ohms from the antenna. thats how you get 1.1:1 ratio which is a perfect match.Also all connectors should be cleaned of any type of corrosion and get the SWR checked with a good meter.

 

No. Waves travel slower through coax. RG8X has a velocity factor of .80.

492 * .80 / 27.185 = 14.47 feet

 

Tune the antenna to the system, not the coax.

Also, for cophasing, you need 72 ohms in your coax.