[sdiy] About that 4-pole filter...

[David G. Dixon]

*** This is a Public Service Announcement ***

To anyone who expressed interest in my 4-pole multimode filter/quadrature
oscillator: After extensive testing, I have discovered a couple of wee
design flaws (a missing resistor on the fourth stage, the need for some
feedback-loop caps in the gain blocks, etc) and will be updating the design
over the next few days.  Probably best not to build until you hear from me
again.