[Antennas] From transmission lines to tuners

[Sandy and Kees Talen]

Karl and all,

I'm interested in info on the Vectronics tapped inductor. What 
are the inductances of the taps and why is the switched inductor
gimmick "a miserable tapped inductor". Seems like a tapped 
inductor would be easy to make and very low cost ....if you 
can define the taps. I've done Q testing with a Boonton 260A 
on pill bottles, CPVC, and PVC as coil forms and find them 
to be quite acceptable relative to air wound. The bigger 
detractor is the adhesive used to hold the turns in place. The 
biggest drop in Q, of course, occurs due to capacitive coupling 
between turns (much worse on edge wound strap type coils)
so "space winding" the turns on the form is mandatory. You 
can cut a grove in the form with a lathe or wind with a "spacer 
wire/string) which is later removed.  

Have a Happy Holiday Season.

73  Kees K5BCQ