Antenna Tuners

Why are there so many different Types of Antenna Matchboxes?

THE SHORT ANSWER:

  

Because we wish to use so many different kinds of antennas on many different bands.

AND

 

It is impossible for one matchbox technology to do all of this efficiently!

 

A DETAILED ANSWER:

 

WE HAVE A LONG LIST OF VERY DIFFERENT MATCHING REQUIREMENTS:

 

  • MATCH FULL SIZE ANTENNAS (i.e. DIPOLE) ON THE BAND ENDS
    • Very easy task.  Most matchboxes do this effeciently - except on 160m.
  • MATCH TRAP BEAMS (YAGI's) ON THE BAND ENDS
    • Very easy task.  Most matchboxes do this efficiently.
  • MATCH LONGWIRE ANTENNAS WITH VERY HIGH IMPEDANCE
    • Many matchboxes, especially those built into the transceivers cannot do this.
    • Many matchboxes that can do this, do so with high internal losses.
    • Some matchboxes, especially purpose-designed matchboxes (typically L-Networks and/or properly-tuned T-Networks), do this efficiently.
  • MATCH PHYSICALLY SHORT ANTENNAS ON 80m AND 160m (VERY LOW IMPEDANCE)
    • Very common task, but unfortunately most matchbox have very poor effeciency on 80m  when doing this, and many fail to find a match at all on 160m.
    • If they do manage to find a match on 160m, then it is usually with significant power loss within the matchbox.  
    • The reason for this is the physical size (and cost) of the large components that are necessary to match 160m.
      • This is the weakest point of most matchboxes.
  • MATCH ANTENNAS ON 10M.
    • The task is easy, but many matchboxes do not have a low enough minimum capacitance or minimum inductance.  As a result they have high power loss on this band.
      • The reason for this is, they also cover 160m and the components aren't effecient for 10m.
  • MATCH OPENWIRE-FED ANTENNAS
    • Most matchboxes are not very good at this.  Their matching range is simply too small to cover all of the possible impedances this antenna may present on the various bands.  Even if they do find a match, efficiency is often poor on some bands.
    • Obtaining a good match on all bands is due more to luck than to the quality of the matchbox.  Length of antenna and feedline play a significant role here.
  • AND MORE . . . 

 

TECHNICALLY, we can solve any of the problems above.

However we cannot do it all with just one matchbox technology;

we need different technologies for different tasks.

 

IN PRACTICE, IT IS IMPOSSIBLE TO DO IT ALL IN JUST ONE MATCHBOX. 

 

THE BOTTOM LINE:

 

IN ORDER TO HAVE GOOD EFFICIENCY IN YOUR MATCHBOX,

YOU HAVE TO SELECT THE RIGHT MATCHBOX TECHNOLOGY FOR THE JOB AT HAND.

 

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