Yaesu FT1000MP Data Modes
The Yaesu FT1000MP has an abundance of ports for data with separate ports for Packet and RTTY. The problem with the Packet and RTTY ports is that the sideband is set by the mode and there is no simple way of changing them making them less than ideal for SSTV or PSK31. The DVS-2 port can be used as a general data port and unlike other ports you can set the side band and other parameters to suit your needs. The only disadvantage is that the interface is slightly more complicated in that you have to set the control pins CNTL 1 and CNTL 2 on the DVS-2 port 'high' (+5V) for it to work (figure 1). However it does have the advantage that it kills the normal mic input when goes into transmit but leaves it fully operational at other times.
The audio from the PC soundcard to the DVS-2 port is isolated by a small audio transformer such as Maplin's LT700 (LB14Q). The 3.2ohm end goes to the soundcard via a 3.5mm stereo plug with only the centre pin and screen being connected and the 1.2K ohm end to 'voice in' and 'earth' pins of the DVS-2 port. It doesn't matter which way round the end of the transformer windings go but DO NOT USE A MONO PLUG as it would short out one of the channels in your sound card. The audio into the souncard is taken directly from the FT1000MP's AF out port which is at a level to directly connect to your soundcard without further attenuation and is independent of the rigs volume control. No isolation is used on the receive side as it was found unnecessary even when using 400W.
As well as making a superb data port you can also use Mikael Larsmirk SM3WMV's Voice Keyer program or Paul O'Kane EI5DI's contest logger's voice keyer function with this port. The recording is made directly via the soundcard using a PC microphone and not via the FT1000MP's mic. You can download both programs free either from www.sm3wmv.com and or www.EI5DI.com .
Figure 1 PTT circuit Figure 2 Audio Input
Figure 3 DVS 2 Port Figure 4 Mikael Larsmirk SM3WMV's Voice Keyer program