Okay, well this is my first article in English here. I decided to do this, because I get lots of question from outside of Germany about my experiences with this small chinese linear amplifier. Thanks to Peter, HB9FGQ who answered on my topic on the FT-817 Facebook group, I was able to make myself a y-cable for my chinese MX-P50M amp. Now I can hit PTT for digital modes such as PSK or JT-65/9. Also the QRG-reading on the electronic logbook is now working fine, as this construction lets the CAT passes through. I went to my local electronic store (Conrad Electronic) which had the needed parts on stock. After I picked up the items I needed about 3 hours for everything.
I have a temperature regulated soldering station, and used 300°C for the very tiny connectors. I made a 1:1 Connection from Mini-DIN male to female with all 8 wires. On the male side, the one you plug into the FT-817, you need also to solder GND and TX GND out of of the package (as Peter sais "piggyback"). You see this one the photos with the 2 cables in one heathshrinking-tube. You better have some experience when you solder those Mini-DIN connectors. Some of the worst things I have ever worked on.
Total price for the 2 connectors were 6 Euro, cable (8 wires, 1:1 soldered) came out of the junkbox. The wire for the amp is an old switching-line from my old PC, also from the junkbox. Fits into the socket of the amp, like it was made for it. First QSO btw was to JA2LWA on 40m, who is 9.300km away.
Off topic (Amp came with no plug to connect to your radio):
I get lot's of emails (sometimes 5 per week) from people that order cheap chinese stuff on eBay and think that I can give free support for them. Everything was already covered in this and my other post here on my blog.
If you have no plug on your amp to connect your FT-817/8 to your amp (only 2 open black and red wires), you just have to get the 8-pin ACC ("DIN") connector and solder TX GND and GND to it. It does not matter if you change red and black, as they will be shorted anyway if you press PTT.
And if you can't find out, that you just have to solder 2 wires, I am not sure if an amp and even amateur radio is the right hobby for you.