decisions for implementation of FreeDV into the UHSDR software. More details
here:
http://freedv.org/tiki-index.php?page=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
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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
