Yaesu Mobile TRX for D-Star

Yaesu does not built any D-Star radios until now (2009). But we have Satoshi's boards to extend these radios with D-Star capabilities:

Kit from www.funkamateur.de
DV-Platine from Satoshi http://d-star.dyndns.org/rig.html.en
Hot-Spot from Satoshi http://d-star.dyndns.org/rig.html.e (see also Update below)

All Yeasu mobile rigs (FT-7800, FT-8800 and FT-8900) have an inverted 9k6 data input. Therefore it is neccessary  to build an signal inverter for the TX data signal:

This inverter must be switched between the output of the D-Star board and the 9k6 Packet input of the Yaesu mobile transceiver:

Additionally the signal polarity of the FT-8800's 9k6 output is also inverted but ONLY in the 2m band. For 70cm this signal is normal. So we need an additional inverter for 2m operation.

With other transceivers the signal level is unknown. Therefore I have build a small circuit which allows flexible selection of signal polarity with two switches:

                   

This circuit is switched between the Node-Adapter (DV-Adapter etc.) and the transceiver.

Using the two switches you can select any polarity and adapt the TX and RX signal to almost any transceiver.

Capacitor C1 ... only needed if the 9k6 input of the transceiver has no input capacitor (most rig have one).

Resistor R7 ... required for many transceivers. It reduces the output level of the transceiver for the Node-Adapter (DV-Adapter usw.). This resistor is required for the FT-8800 and recommended for most other transceivers.

Update for the Node-Adapter:

Firmware versions 3.36 or later have an software inverter. You do not need above circuit.

You still need it for the DV adapter.