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.
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.
- MATCH PHYSICALLY SHORT ANTENNAS ON 80m AND 160m (VERY LOW IMPEDANCE)
- Very common task, but unfortunately most matchbox have very poor effeciency on 80m and 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 components that are necessary to do it right.
- 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.
- MATCH OPENWIRE-FED ANTENNAS
- Most matchboxes are not very good at this.
- 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.