Dear All,

Previously we have been using the ICOM IC-910H transceiver with SATPC32ISS for doppler control for our ARISS school contacts. Due to ISS has both its TX and RX frequencies in the 2M band, we had to use an extra wire between the IC-910H's ACC jack and the PC's COM port to inhibit frequency changes while the radio is transmitting.

Based on the "What's New" document of SATPC32ISS (http://www.dk1tb.de/What%27s%20New.txt), it is noted that the extra wire between IC-910H's ACC jack and the PC's COM port is no longer needed from version 12.8a onwards. However, when we did a simulation of this, we notice that should the frequency changes (due to doppler shift) while the radio is in transmit mode, the TX and RX frequency swaps (TX frequency becomes RX while RX frequency becomes TX) - as what used to happen during previous version when the ACC wire is not installed.

I wonder if there are some configurations that we need to check? Or is there something that we are doing wrong here? The IC-910H is connected via a G4ZLP ICOM CI-V cable to the PC's build in COM port.

Any pointers or suggestions will be greatly appreciated. Thank you.

73, Sion Chow Q. C., 9M2CQC, Also: WQ2C /HL1, 9V1QC, JG1XHM, ex: 9W2QC, AB3IO