|08-03-2007 09:11 PM|
|"W4MAC"||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.|
|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...
|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.
|07-17-2007 08:40 PM|
|07-17-2007 08:06 PM|
|naterg||Well, I need to get off my lazy tail and tune the stinking thing, then I think I will be alright.|
|07-17-2007 07:50 PM|
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.
|07-17-2007 07:38 PM|
|07-17-2007 07:29 PM|
|naterg||It is a smaller whip, probably only like 48 inches... guess I should go with a fiberglass one then... damn. I lose.|
|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.
|07-17-2007 11:00 AM|
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...