Running one antenna with dual coaxial cables?

[LoneRanger93]

I've had dual fiberglass whips on my truck for a few years now mounted behind the cab, but since I just got a cap I couldn't use my old brackets. I'm waiting for my new mount to arrive but I am just going to use one antenna this time. I'm just wondering if the unused coax will act as an antenna and interfere with the performance.

So should I get a single coax or can I still use the split coax?

Thanks!

 

[Simple_serf]

Can you get away with using the split..probably.

However, the best thing to do is to use a single piece of coax... It won't act as an antenna...coax is shielded. My concern would be the standing wave ratio if you left the open end on there, as well as the possibility of spurious emissions which can cause interference with others (those others include those outside of the CB band (!!!))

 

[LoneRanger93]

Can you get away with using the split..probably.

However, the best thing to do is to use a single piece of coax... It won't act as an antenna...coax is shielded. My concern would be the standing wave ratio if you left the open end on there, as well as the possibility of spurious emissions which can cause interference with others (those others include those outside of the CB band (!!!))

a single coax is cheap enough, I don't have a problem snaggin one and doin it right. I just thought I could be lazy

 

[nightshift]

Try It

I just re-read your post. I missed the part about the cap (Sleep deprivation. Sorry about that).

If you're set on a single antenna, definitely get a single coax, 50 ohm, like rg58u, mini 8, or lmr240. Try to stay away from the Radio Shack cable, as it is generally of mediocre quality. Again, Firestik and others have a cable assembly for you if you're not into putting one together yourself.

You'll probably get the best performance & pattern if you mount your antenna permanently in the middle of the roof of your cab. If get the Wilson 1000, you'll get a dynamite antenna with the coax harness and everything. It's not the greatest coax, but it'll do. Whatever antenna you use, you must buy or borrow an SWR meter (they're pretty cheap) and adjust the length of your antenna for the lowest SWR. Money and effort spent on your antenna system will give you the best bang for your buck.

Have fun with it.

 

[Ozwynn]

you better put a dummy load on the unused cable or you will burn out your finals. or get some some Rg-58, any multiple of 3' works fine. 50 ohm works better that 75 ohm for your SWR on a single stick. you use Rg-59 (75 ohm) for 2 sticks. if you use twins then your sticks should be separated by atleast 7'. This why I get better range with a single 60" antenna with 18' of Rg-58 than I did with twin 102" whips that where only 6' apart.

right now I got an SWR of less than 1.2:1 on channel 19 ........ I couldn't get that with airforce equipment under labratory conditions. I can walk over people for 20 miles and receive for 22 miles with a stock cobra 29 and a 60" K40 tunable fiberglass whip


always always always always calibrate your SWR for the channel you use most of the time.