decisions for implementation of FreeDV into the UHSDR software. More details
here: http://freedv.org/tiki-index.php?page=FreeDV+Specification
RTTY (RX & TX)
How to operate
• select digital mode "RTTY" as described above
• set AGC speed to very long (very slow) or (best) switch it off completely
• change mode to RT-L (LSB aka normal polarity, Mark is the high RF frequency) or
RT-U (USB aka reverse polarity, Mark is the lower RF frequency) according to
desired RTTY mode
• use filter bandwidth 1.4k BPF --> do not try to use a very narrow bandwidth, this
does not help the decoder, maybe it helps your ears, but the decoder needs
relatively wide bandwidth to avoid distortion decoder errors
• with button M1 change orange focus to box BD
• with encoder 1 adjust baud rate (BD)
• with button M2 change orange focus to box SFT
• with encoder 2 adjust shift (SFT)
• adjust frequency until mark and space frequencies are accurately aligned with the
vertical markers
• if vertical markers are invisible, change their color in Display Menu --> TX Carrier
Color
• enjoy RTTY being decoded and displayed as running text
Ham RTTY:
• RTTY LSB mode = RT-L
• shift 170 Hz
• 45.45 bauds
• signals at 915 and 1085 Hz
Shipping RTTY broadcast (marine weather, warnings etc.) of the Deutscher
Wetterdienst DWD:
• RTTY USB mode = RT-U
• shift 450 Hz
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