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-   -   Antanna question (http://www.wranglerforum.com/f40/antanna-question-9646.html)

naterg 07-17-2007 11:00 AM

Antanna question
 
Ok, so I run a whip, my buddy runs a fiberglass firestik. He swears up and down that the fiberglass is better... I don't know a whole lot about this, I bought the whip because I snapped a fiberglass one I had on my jeep. I also like the look of a whip as well as the flexability. So what are the pros and cons to each? Which one is the best? Or is there just no significant difference?

Edit: Apparently I don't know how to spell antenna either...

skeeter 07-17-2007 04:06 PM

What kind of whip?
A 102 inch whip will out out perform a firestick. The problem is 102 inches is a little too long to be manageable.
Coil antennas vary from manufacturer to manufacturer, a good one will still out perform a firestick but will be more expensive at the same time.

naterg 07-17-2007 07:29 PM

It is a smaller whip, probably only like 48 inches... guess I should go with a fiberglass one then... damn. I lose.

kg4kpg 07-17-2007 07:38 PM

Quote:

Originally Posted by skeeter (Post 105729)
What kind of whip?
A 102 inch whip will out out perform a firestick. The problem is 102 inches is a little too long to be manageable.
Coil antennas vary from manufacturer to manufacturer, a good one will still out perform a firestick but will be more expensive at the same time.

Exactly why I use the Firestik. Mine is on a spring which works prett good. But if it does break, it's only 1 bucks to replace. As far as performance, I've never had a problem with RX/TX.

skeeter 07-17-2007 07:50 PM

Quote:

Originally Posted by naterg (Post 105781)
It is a smaller whip, probably only like 48 inches... guess I should go with a fiberglass one then... damn. I lose.

If you already have a whip then use it, there's no reason to fix what ain't broke.
If your buddy is claiming his is better, have him show you the difference. Park next to each other and start tuning through the channels till you find a weak signal and see which of you "hears" it better.

naterg 07-17-2007 08:06 PM

Well, I need to get off my lazy tail and tune the stinking thing, then I think I will be alright.

kg4kpg 07-17-2007 08:40 PM

Quote:

Originally Posted by kg4kpg (Post 105783)
Exactly why I use the Firestik. Mine is on a spring which works prett good. But if it does break, it's only 1 bucks to replace. As far as performance, I've never had a problem with RX/TX.

eerrr, I meant to say 15 bucks. But I agree. If what you have works, put the money to other mods.

JeepCrawler98 07-17-2007 11:00 PM

Relax - a quality 48" whip vs. a 48" firestik; the whip will outperform hands down.

If you look at a firestik you'll notice it's basically a fiberglass rod with some copper wire wrapped around it at spacing that varies. The higher you go up the antenna - the closer the windings get. This results in an impedance increase as you go up the antenna physically (decrease electrically as it's a top load antenna); impedance being the resistance to electrical change (in this case RF). What this means is that only a select portion of the firestik is physically used in effectively transmitting.

Why the impedance ramp? It results in easier tuning across a broad range in frequency - very usefull when you have such a short antenna for such a long wavelength (11 meters - a 5/8 or 1/2 wave antenna would be 5.5 meters or so, a 4' firestik is barely over 1) which makes tuning a challenge.

Compare this to a standard whip on top of an impedance matching coil (we'll ignore the 102" whips in this case). This system relies on the natural impedance of a metal length of wire to be adapted through a series of windings in order to match the 50 ohm load most transmitters expect to see for the peak power output. This means once this is achieved - the WHOLE length of antenna is used to radiate RF energy, instead of only a small portion of the antenna being used in a significant way. Downside? They're a bit more specific in where they are considered 'tuned' as they are tuned to a very specific frequency.

Creating impedance matching coils is no easy feat either however. IMO a cheap radioshack whip deal with a half ass coil will lose to a marginal antenna such as the Firestik, however get something decent (which there is quiet a bit out there), and you'll have a pretty significant upper hand.

I do run a firestik... why? I got it for free, and even if not it's a cheap antenna - which is important to me since I don't really care about my CB setup as long as it works on the trail [I have a ham setup for anything more demanding]. However FireStiks are a LONG throw from a quality antenna if that's what you're wondering.

MOz 08-03-2007 01:20 PM

Why couldn't my electrical engineering professor explain it that simply back in college?

I'd like to see if anyone has ever installed a moonraker beam antenna on their ride and just drag along the long wire for reception...

"W4MAC" 08-03-2007 09:11 PM

Nah, not a Moonraker. But before I switched to ham, I had a CB in a Suburban, with 3 Fightin Sticks, basicly a 3 element vertical beam. Ran 6 Leece Neville 320 alternators back then too.


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