[Elecraft] K3 'KIOB upgraded' + P3 + SPE 1.3K-FA amp CAT chain not working

[Philippe]

Hello, 

I have read previous posts from this reflector and instructions from
different sources without being able to have my K3 connected to SPE
amplifier with CAT. 

I have upgraded my K3 (S.N.#4004) with the new KIO3B so I connected my
computer (running Windows 10) with the USB cable and the P3 with the
CBLP3Y as presented on page 18 of the K3S Owner Manual. Everything is
working fine for months. 

I recently got an Expert SPE 1.3K-FA I am trying to connect to that CAT
chain. I read on this reflector I needed to connect a RS232 Y cable
plugged to the CBLP3Y, the PC DB-9 port on the P3 and the CAT port on
the SPE. This made the connection between the K3 and the P3 not
functionning, missing the green and red bars from the 2 K3 receivers on
the P3. 

Then I made another RS323 Y cable, using only TXD to RXD on the SPE
side. It was better but the USB port on the PC USB link stopped
functioning. 

On the K3, RS232 is configured as 'USB' and on the P3 the baud rate is
'38500'. I used on the SPE both 'Elecraft' and 'Kenwood' CAT settings
without any success but if I only connect the K3 and the SPE using the
CBLP3Y cable + DB adaptor on the SPE, it works.  

So does someone have experience with this configuration and can let me
know how it should be connected to have it working? 

Thank you   

73,

-- 
Philippe Givet
F5IYJ (NK2F)