[Mobile-Portable] Webster Bandspanner Info

[Tom Bates]

>>Were they also needed for the higher bands or just 80 &
40m?


My first bandspanner should be arriving today, and one of the first tests will be to determine it's input Z when tuned to RESONANCE on 80M (which will be my lowest freq used).  From this point, it SHOULD be  relatively simple to determine the required matching component.  I have tried many matching schemes on many different mobile antennas, but have had the greatest overall success when using a shunt matching coil.  When I get the desired match at resonance on the lowest band I intend to use, the match is good from there up thru the higher bands where the inductor becomes more transparent as freq increases.  One of this type  coil is available comercially from  www.repdesign.us or you can very easily wind your own by wrapping just 10-15 turns of something like a 14 AWG wire around a broomstick for a form and attaching right across the antenna feedpoint.

If you're interested in seeing some of my mobile installations, see several pix on my QRZ.com bio.

Happy Mobiling,

Tom  -  AA1NZ