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Center load VS. Base Load?

Soldaun

Member
Aug 1, 2009
21
0
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A while back I got a CB from a garage sale for 5 bucks but it's practically from when CB's first came out so it isn't exactly the best. Well my buddy's dad is getting a new CB for his Semi and threw out his old one so I snagged it, a Cobra 29 WX NW ST soundtracker, but I'm not sure if it works as he did throw it out. Well I'm looking at antenna and want to know the difference between center load and base load, thank you.
 

Thank you for the reply, is there a specific brand that would do better than most, or even a specific model? I have heard of Wilson but I know there are other brands out there.
 
Loaded Antennas

There actually are three types of loaded antennas: base, center & top loaded. Center loaded antennas are real popular. The market is very active with these type of antennas due to there performance and broadband ability. The major players are Predator 10-K, 55's, Mr. Coily, Monkey Made, Tram, K40, Wilson, Ranger and Browning. When an operator buys a few brands then end up settling for one particular brand. Each antenna and its materials made be good for the short term but long term degrade. Aluminum and stainless sometimes seize up at their contact points. Plastic housing over the coil may develope a crack. The number one issue is moisture entering in an area where it does not need to be. You will find guys standing behind a certain antenna because they experienced the performance of what needed to reach their goals. Either you can set your goals as so-so or set the bar high and go all out. The choice is ultimately yours. It is my experience that at Cowtown Antennas, Kale Cavel offers a lifetime warranty. Now that is a plus. As far as moisture he coats the treads with a anti-seize lube. Antennas are subjected to damage and with the Predator 10-K each section can be replaced separately. Then if your needs become more custom you can also change the shaft length. For example I have a Predator 10-K with a 22" shaft. This brings the coil closer up and over the roof line of my truck. So a lot to think of.
 
The biggest differences in how an antenna is loaded amounts to being practical. What's the most efficient that you can manage.
I think you will find that the continuously loaded type antennas are the most common, followed by the base loaded ones, then the center loaded ones and then the top loaded ones. Top loaded antennas are not very common for a good reason, even if they are the most efficient. For practical purposes, this is almost the exact opposite of how they rank in usability for the average person.
The continuously loaded, helically wound antennas are the -least- efficient! Sorry, but that's a fact. That deals with the efficiency of coils in general, specifically with their 'size' and 'shape'.
Top loaded antennas are the most difficult to make practical for several reasons. I'll bet you can figure those reasons out for your self.
Center loaded antennas are probably the 'best' compromise in practicality and efficiency.
Base loaded antennas are the most common, the most 'practical' for the average person, and are not all -that- bad to start with. They can take much more 'abuse' than the other kinds of antennas.
While there definitely is a difference in efficiency between all these kinds of antennas, in general, that difference isn't going to amount to much at all.
If these different antennas are of a comparable size/length, their effectiveness is going to also be comparable (radiation pattern). So, at least for me, the deciding factor is just how practical the thing is going to be for me. How long will it 'live' in the use I put it to. That typically means a base or center loaded antenna. Does that mean I'll have the most efficient antenna possible? Nope, but then, I don't expect 'perfection' very much. 'Good enough' works!
- 'Doc
 
Just for grins ... of the types mentioned, where do the fiberglass whips land?

Most of them are continuously loaded, even if they try to advertise or fool you into thinking they're top loaded. If you see a spiral of wire starting from the bottom and going all the way to the top, it's continuously loaded.
 
Most of them are continuously loaded, even if they try to advertise or fool you into thinking they're top loaded. If you see a spiral of wire starting from the bottom and going all the way to the top, it's continuously loaded.


A lot of them have either a long slow spiral up the shaft or a straight wire and then a close wound section at the very top. You can tell those because they tend to be thicker for the last several inches at the top.
 
ive always wondered about this also.i never had the funds to buy all 3
types of antennas so i just got the most practial for me.thats a wilson 5000
mag mount.on my daily commute i drive about 25 miles 1 way .say with a stock
29 or 78 would i have even the slightest edge using a trucker wilson on a quad pad
over the baseloaded wilson 5000.i imagine the difference would be slim maybe
1/2 -1 s unit .but that would be the difference between being heard or not...right
 
ive herd/seen a station with stronger modulation take out a station showing more signal on the meter . no one thing is going to make a station top shelf , its the balance of a few things together . antennas DO NOT affect modulation , but everything in front of the antenna is compromised if a antenna isnt installed correctly or just isnt a good fit for the vehicle . the vehicle is half of your mobiles antenna system (the groundplane) and while one antenna may be the bomb on one verhicle it may not on another .

as others said , it a compromise between performance and what youre willing to allow height wise . coils cause loss where ever they are , but height is might and the 108 is still what all other antennas aspire to equal or (according to advertising) to beat .

MFJ Enterprises Inc.
 
Just for grins ... of the types mentioned, where do the fiberglass whips land?

probably a better understanding about why fiber-glass antenna is worse can be had by reading the k0bg page on antenna efficiency.
(An antenna with high Q is very efficient, but has more narrow operating bandwidth. cant have both.)
The more material within the field of the coil, the more the Q will be reduced.
Wilson 5000 and predator 10k are good antennas because their coil has high Q.
Fiberglass has poor Q coil because there is so much material around it and the wire size is too small, and it has alot of distributed capacitance. Coil Q is more important than base-load vs center-load.

Like booty said, the ground plane is half the antenna. The best antenna will be garbage if you have ground losses.
 
probably a better understanding about why fiber-glass antenna is worse can be had by reading the k0bg page on antenna efficiency.
(An antenna with high Q is very efficient, but has more narrow operating bandwidth. cant have both.)
The more material within the field of the coil, the more the Q will be reduced.
Wilson 5000 and predator 10k are good antennas because their coil has high Q.
Fiberglass has poor Q coil because there is so much material around it and the wire size is too small, and it has alot of distributed capacitance. Coil Q is more important than base-load vs center-load.

Like booty said, the ground plane is half the antenna. The best antenna will be garbage if you have ground losses.

Oh yeah!

q.jpg
 

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