SmartSDR A3.9.4 transmit problem on FT8

Colin O'Neill

I'm running a Flex-6300 on HW version v3.1.12.51 which was working fine on SmartSDR for iOS on my iPad Pro and iPhone 11 Pro Max on FT-8; both using the latest 13.5.1 iOS.
After I installed the latest SmartSDR version on my iOS devices there has been a problem with the transmitted tones, which intermittently have a clicking or sometimes sawtooth effect on them which can be heard when monitoring, or seen on the transmission waterfall. Consequently the transmissions are not being decoded. Occasionally the problem goes away for a short time, then returns.

If I run the Windows SDR program with WSJT-X everything works. WSJT-X even works fine if I run if from my PC with SmartSDR iOS running.

I have tried slowing the FPS rate and speed on the display, connecting the iOS device directly to the radio via ethernet using an adaptor, thus cutting out the network, to no avail.

I have a pretty ancient iPad mini which still has an older version of SmartSDR on it, and I can still use the FT8 tool on that so there is something in the latest version which doesn't agree with my particular devices, or perhaps the way they are set up.

I have been in contact with Marcus, who is really helpful and has offered a lot of suggestions but none has worked. Unfortunately, he is unable to reproduce the problem on his equipment so cannot help any more at present. He has kindly offered a refund but I prefer to support him and persevere until I can get it working.

I wonder if anyone else has noticed this problem?

Thanks for any suggestions you may have.

Colin G0CGD