I just got a YR-901 a few days ago I am using it with my 902DM on CW I am getting everything to work right. But with RITY what mode do I use ???? USB-FSK. Thanks email@example.com
When in doubt the best thing with the YR-901 is to try it. Not sure if the YR-901 is capable of reverse decoding or not. If it has that feature then all you have to do is switch it and properly tune in a RTTY signal. If it doesn't have that feature then use LSB and try to tune a RTTY signal. It would be best if the signal had as little interference as possible. Check your mark and space tuning indicators for proper tuning. After all this time the YR-901 detection circuits may have drifted away from their proper mark and space tones. You may need to retune them. Getting a manual on the YR-901 is possible but you will have to pay for it. I couldn't find one on the internet for free.
Oh yeah, if you were unable to tune a RTTY signal on LSB then try USB. If neither works then it probably needs tuning.