First of all, I would like to thank your for your effort to bring us PowerSDR for home made rigs. I managed to build a homemade SDR based on Si570 last year and was very pleased to be able to use PSDR. It is called the Lima SDR. Now, I've also tried to use it for cw but faced the problem. I've configured PSDR to detect my paddle on a rs232 interface. I've learned that I have to disable the option “Disable PTT” so that PSDR will recognize the rs232 interfaces. For cw this works well. But when I switch to SSB, the tx is triggered immediately. I can't manage to configure an external ptt switch, as the tx is always going on air regardless of how the external interfaces are configured. I think that I have to do something with the USB driver because this happens, only if I enable the USB option in PSDR. If the USB option is disabled, the PTT remains down.
So, at the moment I always have to switch the “Disable PTT” option when changing between cw and SSB operation. A very inconvenient way to use the software. Do you have any idea why the USB driver switches my tx on air? Maybe, there is another configuration to change. It would be great to have paddles and an external ptt switch working on my sdr.