The 8900 should have the 6 pin minidin packet port on the back of the radio.
This port is a perfect match to the TNC-X. The minimum needed is TXA, 1200 RX,
PTT and Ground. The pin numbers escape me right now.

Just make sure to get your TX audio level right and it should work fine.

Jason KE4NYV
RPC Electronics
www.rpc-electronics.com

--- In tnc-x@yahoogroups.com, "kz6oscar" <lrahnz@...> wrote:
>
> I've used my TNC-X with an FT8800 with no problems. I hooked up data in, data
out, and PTT only and run it with the squelch always open.
>
> Logan, KZ6O
>
>
>
> --- In tnc-x@yahoogroups.com, Chris Wall <chris@> wrote:
> >
> > Good afternoon,
> >
> > I'm mostly done with my TNC-X assemble, but want to be sure before I
> > wire in my tx/rx/ptt. I have a Yaesu FT-8900R, and according to the
> > manual it uses pin 1 for data in 10k ohm/40mV for 1200, pin 5 for data
> > out (10k ohm / 300mV) and 3 for PTT (ground to assert). There is also
> > pin 6 for squelch control (+5 open, 0v close).
> >
> > Are these levels that the TNC-X will "live" with if I wire straight into
> > phono plugs (1/3 into a TRS, 5 for the TS)?
> >
> > Lastly, should I have any concerns about using the squelch control?
> >
> > Thanks in advance,
> > Chris
> >
>