[GreenKeys] PLL TUs

[Ralph Mowery]

----- Original Message ----- 
From: "WB6BLV" <wb6blv at inreach.com>
To: <GreenKeys at mailman.qth.net>
Sent: Wednesday, December 13, 2006 10:57 PM
Subject: [GreenKeys] PLL TUs


> 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
>

John, you are correct.  I was thinking of the 567 chips.  Like I mentioned 
it was about 25 years ago and I had forgotten the number of the chips.  I do 
remember seeing a circuit like you mentioned in an old 73 magazine.  Also 
think I remember a circuit using a pair of the 567 chips, but not too sure.