[Elecraft] K3 Variable Xtal Filters

[Brett Howard]

I was finally going back through and looking at how the K1 filter works and
really dig the idea of using the varactor diode to get the variable filter
widths.  Why was fixed xtal bandwidths chosen over sticking with this
design?  Especially now that I hear of a possible variable filter that will
be able to plug into one of those locations?  It seems that with that filter
you'd have pretty much all the bandwidths you need (over however much range
you can get out of the C range you get).  Maybe I just answered my own
question.  Is it just that you'd not be able to get a wide enough range of
widths by using varactors?  So does that mean that when the variable filter
comes out its only going to be for use at the lower end in the CW spectrum
or am I missing the point here?