[Premium-Rx] Design Assistance Sought

[Keith Densmore]

Good Day All,

There are a lot of smart people on this list so I am going to throw out
this inquiry here first.

I have a beautiful Harris RF-550 receiver. These rigs use up down switches
for tuning  (6 switches in total, one for each decade).

I would like to add the option of rotary tuning  using an encoder.  The
radio supports external tuning, it conveniently has a 36 pin Centronics
connector on the back which is designed to bring in 22 BCD lines (4 for
each decade, but only two needed for 10 MHZ selection. It expects TTL level
positive (5 Volts). Each 4 liine BCD can encode the 0-9 needed for that
decade.

The problem is I am digitally design challenged, to say the least.  I am
open to any way of doing this from CMOS chips through a Raspberry PI, to a
dedicated laptop controlling it.  But I need someone to design it.  I'll
bet  one of you retired EE's or digital gurus could do it in your sleep. I
can build a circuit once I have the schematic.

I'd be glad to pay for the design work, maybe not at commercial rates , but
certainly at a reasonable rate. Perhaps you know of something that already
exists that could be modified to use.

If you think  you can help, have any ideas or suggestions  please email me.
Hoping to hear from you.

Keith ve3ts/ve3gem