antenna matcher in a mobile?

[natureboy757]

Any1 use a matcher on their mobile set up? If so what r the benifits and negatives? And what is a good matcher for a mobile that can handle 1600watts? On cophased set up would I need 2 matchers? Thanks for any help

['Doc]

Well, I was going to make a suggestion or two till I got to that power level part. Considering that, the best advice I can give you is forget it.
I have a tuner built into the radio (no, it's not a CB radio) and an all band adjustable antenna. With this particular antenna I really don't need the tuner unless I'm in a hurry to change bands. Then, I just need to get close with the antenna and the tuner takes up the 'slack'. I had the choice between having this tuner built in, or having twice the output power. I very definitely like the tuner rather than more power, it's just handier, of more use to me.
With tuners, the power handling ability directly affects it's size. Something for about 200 - 300 watts or so can be fairly small. For power levels more than that, especially for over 1000 watts, expect very nice sized tuners, as in large. That deals with the size of the components required at that power level and there's just no way around that. It also deals with just how far 'out' the antenna will be on the frequency of use.
The 'best' place for a tuner is also the hardest place to use one, at the antenna's input. When you use one at the radio end of a feed line you are making the feed line part of the antenna as far as impedance matching goes. That can certainly work, but it does put the feed line under a stress it wasn't designed to handle, which means it does have limits of use.
Dual antennas aren't impossible to use with a tuner, but use just one tuner means putting it at the junction where the two phasing lines come together, and then just a single 50 ohm feed line to the radio, typically.
The biggest 'catch' for what you want to do is that power level thingy. I only know of maybe one or two tuners that are capable of that level. Cut that power in half, and you more than double the possibilities. Get it down to under 200 watts and you start getting into the automatic tuner ranges. Of course that says nothing about cost. If it says 'high power', or 'automatic', expect a large price.
Depending on exactly what you want to do, you would probably be better off using a well tuned antenna for where ever you want to operate.
- 'Doc


Then again, I'll make you this fantastic deal on a screw driver antenna that will definitely handle 1600 watts. I also guarantee you'll have to change your britches when I give you the bill! I got a feeling that ain't gonna fly...

[Red Warrior]

Unless you plan to change bands a lot a tuner between the amp and antenna does not make sense.

Now if you have a mismatch between the radio and amp, and you don't want to modify either to improve the match, a matcher makes sense.

[natureboy757]

Thanks 4 the comebacks- this was just an idea that I was thinking of trying to do some fine tuning on my station. My swr is low but I just wanted make sure that I was getting a good match on my antennas.