[GreenKeys] PLL TUs

[WB6BLV]

Hi Ralph,

I think you are talking about repeater control using the
567 tone decoder chip.  I am referring to the designs
that use the 565 PLL to track FSK in the 2 - 3 KHz
(or elsewhere as needed) range.  Most of the designs
consist of a 565, followed by a comparator, and at times
there is a 741 or similar band-pass filter ahead of the 565
to eliminate out-of-band tones.

John