Retrofit CAT on older QCX (serial #675) #cat

Ham Radio

Looking thru the latest QCX manual, I can not seem to find docs on the CAT pins.  What pins are RX and TX on?
Probably in the manual? Nothing on the schematic.  I assume these are TTL levels and a RS-232 to TTL converter will do the job.

I just flashed the firmware to 1.05.  Attached is a pic of my old QCX with a laser cut case that I made years ago.

Looking at the schematic,  I need to add 2 resistors, 1 diode,  and a header

Has any one done this upgrade?  A pic with the suggested placement of new parts on the older rev board  (and the new CAT header) would be great.

Thank you for reading my post.

73, Bernie, VE3FWF

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