I've been looking for information on varactor-tuned front end/preselectors
and really have not found much in the way of practical/DIY implementations.

I've seen the commercial offerings from (e.g.) www.polezero.com and vague
references to others.

Can any of you here recommend a text/app notes/practical circuits that can
be studied and/or emulated? I'm interested in VHF applications that could be
uP controlled (via D/A, etc.)

Thanks,

Bill