[Elecraft] Add-on for a k3- ICOM band select voltage

[Doug Faunt N6TQS +1-510-655-8604]

On the chance that someone here can give me some hints, I'll put out a
description of a project that I'm working on.

I want to provide the ICOM bandselect voltage derived from the band
select outputs on the K3.

I can easily do it the last century way, using a 4067 CMOS mux (a 24
pin DIP package), and a bunch of resistors (and that's in progress).

But a more modern way would be to use a 8-pin PIC and an op amp to
integrate and amplify a PWM output (two 8 pin packs and a just a couple
of resistors).  I think.  But I'd like some pointers to information on
doing the latter.  Any hints?  Good sources of information?

73, doug