In looking to build a tuner, I was looking at an L-network tuner, with
switched inductance. If I also add a switch to make it a
series-network (capacitance "before" or "after" inductance), what would
be the limitations of such a design? I.e. What types of antennas, or
under what conditions would it be inappropriate?

Thanks.

"marc" wrote in news:1169823069.024417.273600
@v45g2000cwv.googlegroups.com:

In looking to build a tuner, I was looking at an L-network tuner, with
switched inductance. If I also add a switch to make it a
series-network (capacitance "before" or "after" inductance), what would
be the limitations of such a design? I.e. What types of antennas, or
under what conditions would it be inappropriate?

Thanks.


Hi Marc:

TenTec has made tuners of that design for many years. I have one in my
shack and it works very well for me. The advantage of the L-network over
the more common T is in ease of tuning. The L-network has only one
correct tuning spot for each load. The T network can have several
"matching points" some of which can result in large internal losses
instead of an efficient match. The L network has slightly less loss when
matched than the common T network. The main con for the L network is the
requirement to switch the capacitor around to match loads that are
greater or smaller than the input load.
Other than the above both networks do the same thing and there is nothing
T network can do that the L network can’t and it needs one less capacitor
than a T network.
You can see I’m biased to the L, try one you will like it.

John Passaneau
W3JXP State College PA