[Amps] Russian power L-coupler

[Bill Fuqua]

    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