You are assuming the Varicoupler is supposed to cover say .5uH to
80uH. Which is not its usual application. It is often use to fill in the
gaps between taps on larger coils. Also, as I said in a L-Network the Q's
are low anyway. An L coupler requires continuously variable inductance and
capacitance to assure impedance matching.
While we are at it lets compare other means of changing inductance.
I have always been amazed how well roller inductors work considering the
series of connections that the current has to travel thru.
First, there are usually 2 sliding connections on each end of the roller,
then there is the connection between the slider and the roller and finally
there is the very small contact area between the roller and the coil.
Now compare that to a switched inductor like a B&W 850 with a larger
sliding contact and really huge switch contacts. Naturally everyone has
their preferences but there are applications that a varicoupler is just fine.
73
Bill wa4lav
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|