I need an LF to 30 Khz preselector (passive) for a homebrewed receiver
I'm building. I have most of the details worked out, but I am stuck on
the preselector design.

I want one band to cover 50 Khz to 500 Khz (or 1 Mhz). The second band
would be 1 Mhz to 30 Mhz. 50 ohm input with moderate Q (don't want to
have to retune it every 100 Khz. The LF unit can be very high Q,
peaking it every few Khz is ok as most of the signals in that range
are narrowband signals anyway. Input impedance is standard 50 ohms.

I'd REALLY like to have one assembly do the entire job, but it appears
to be a tall order as that's quite a wide range to cover with one
tuned circuit.

Google returns to many hits even if I narrow down the search
parameters, I tried google.

It appears I need to use some sort of permeability tuned variable
inductor in conjunction with a variable cap. Have no idea how to go
about this or where to buy permeability tuned inductors.

Any suggestions?

T