Best Setup?

[lakemarykid]

I have a 1994 F150 Extended Cab. I have a Cobra 25 LTD Classic. Right now it is hooked up to 50ft of coax and i made the mistake of rolling it up when if anything i should have zigzagged it. I have my antenna mounted to the tool box in my bed. The toolbox is held down by "J Hooks" that go under the bed rail. I have the cb hooked up to a good power source and ground. But i need to know what would be the best setup to run from the cb back. Ex: length of coax, an extra ground wire?. I am using RG58U coax now and i am sure i should shorten the amount of coax i have. I am also running a 102" Steel whip mounted on a 6inch spring and a l mount that is mounted to the box with 4 bolts and nuts.

-Curtis-

 

[Cheech]

Only run the amount of coax you need to get from the antenna to the radio. There is no magic length that will make it work better so just run what you need. Also on the isue of grounding most people will run a ground strap of wire from their radio to the nearest point of ground. the point in the ground is to bleed off any excess RF and so long as your toolbox is grounded well you should be fine there. Also I assume you have an SWR meter to check your match after everything is setup just to make sure the antenna system is working properly. Good luck and welcome to the forum! 8)

 

[BIONIC_TEXAN88]

run the coax length you need from radio to antenna. get ground straps and ground your toolbox to frame on each side of box.

 

[lakemarykid]

By ground straps do you mean a piece of wire or those thin metal straps with holes running down the middle of them? And when grounding the toolbox, just attach the ground to the toolbox with a nut and bolt then again on the frame? Sorry guys im just trying to get the best reception a nd new to it. And to adjust the SWR's on my whip i need to cut it (1/8th of an inch at a time) since it is non adjustable like a firestick right? Also would it be ok to just cut my coax to length that i have now?

PS: Thanks for the welcoming. Once i get all the kink's worked out i will start tweaking the CB first i need to get the basics worked out.

-Curtis-

 

[Captain Kilowatt]

All good info above. As said there is no "proper" length of cable other than what it takes to go from radio to antenna.As for zig-zaging cable instead of coiling it up,it makes no differance. Some will say that coiling it up causes it to act like an inductor and choke off the signal but it won't do that.The ONLY time it will do that is when RF is flowing on the OUTSIDE of the coax cable shield and a coil at the antenna base can be a good thing. I would certainly shorten the cable you have but until then do not worry about coiling it up. I have done tests up to 450 MHz with up to 100 feet of cable and coiling it up makes no differance.

 

[BOOTY MONSTER]

this is a great site (actually by King Mudduck,a forum member here) that can give you all the info and more that youll need to set up you mobile . its also broken down into many focused segments and is written so you dont have to be a tech head to get what hes saying .

http://kcscbradiowebsite.tripod.com/id11.html (thanks king Mudduck)

 

[W5LZ]

Curtis,
A ground strap is something that makes a good (meaning constant, not intermittent) electrical contact between two things. It should be strong enough to stand any mechanical flexing/vibrations, and 'large' enough to handle the typical current flow. From there it's sort of whatever you happen to have handy, or the most of, sort of. From the equipment you listed, the current handling ability isn't gonna be all that 'big', so maybe some #12 or #14 wire ought'a work just fine. If those 'J' bolts on the tool box are making electrical contact with the bed of the truck, they will probably work just fine too. (Not really, but good enough. Add a ground, won't hurt a bit.)
Corrosion, or the metal deteriorating in weather is the biggest problem. Some metals 'rot' away faster than others. Unless braided copper is 'tinned', coated with something, it just doesn't last too long. The absolute bestest grounding conductor is basically whatever you happen to have, or can get without breaking the bank, you know?
Good luck, and have fun!
- 'Doc

 

[hotrod]

ya definately cut coax till lenth ya need .in most installs 18ft
is uasually the norm.but theres no magic number.as far
as adjustyinfg swrs dont trim the whip muntil ya get the
swrs checked first.most 102 whips whith spring shouldnt
need any tuning.if swr is higher than 1.5 from ch.1-40
thats usually means theres a grounding problem.

 

[Cheech]

Yeah should have mentioned what hotrod noted there earlier, you should never have to trim a 102" whip. You may also want to try it with an without the spring to see what matches better but when it comes to matching the thing ground is a key factor in how it will match. Also as W5LZ mention weather is another isue with grounding. Also not sure if it was mentioned before but you want to keep the ground straps or wires as short as possible. I would recomend using something like 10 or 12 AWG wire and conecting to the box using ring terminals and solder the conection into the terminal so weather will not couse it to degrade over time.

 

[lakemarykid]

Sounds good guys! I really appreciate all the help. Very welcoming forum. Most of the time when you ask a simple question you get bashed but not here.

Looks like i will be taking to wires on each side of the toolbox down to the frame. Would it matter if i used braided/stranded or solid copper wire? So for right now having that extra coax really won't matter it's just useless and taking up space?

Here is some of my setup:

Here you can sort of see my mount. Im at school and don't have a better picture on my photobucket.

Here is another somewhat view.

-Curtis-

 

[Cheech]

stranded or solid wire will work just fine. Nice truck 8)

 

[bigred222]

nice truck. looks like quite the mobile.
try to get yourself some RG 8x or rg 8u its a thicker and more durable.

 

[AudioShockwav]

I would not use Solid wire, it will fail after a while from vibration, stranded would be better, and even better yet, is some copper braid that can be stripped off the outside of some old coax. Make sure you clean off the paint down to bare metal were contact is made, then protect it from rust with a little paint after it is bolted down tight.

73
Jeff

 

[BIONIC_TEXAN88]

sweet ass looking truck!! I used copper braid that I stripped off old coax as audioshockwav suggested.