K1EL K45 CW Keyboard and Reader Manual K45B
K-45 User’s Manual - Rev B.0
3/8/2023
Page 19
GND
KEY
FSK
GND
FSK
KEY
FSK=PTT FSK=KEY
Figure 17 – RTTY Output Port Assignments
USOS (Transmit UOS) On/Off
To improve transmit integrity at the expense of extra FIGS characters, USOS mode will send two FIGs
characters whenever a figures character follows a space. This reinforces the operation of UOS at the
receiver which forces a letters transition after every space.
Reverse/Normal
This controls the sense of the FSK output. In normal mode (Not Reverse), Mark is signaled when the FSK
output is OFF, and Space is signaled when the FSK output is ON. In reverse mode FSK if on during Mark.
AUTO LF/CR On/Off
When Auto CRLF is on, the K45 counts the printable characters in a line and after 45 characters, an
automatic CR/LF sequence will be inserted after the next space. The character counter is reset after CR/LF.
This is a very valuable feature for conversational RTTY. The operator can type away and not have to worry
about running over at the end of a line.
Figure 18 – RTTY Setup Menu 2
Baud Rate
The K45 supports three operational speeds, 45.45 (60 WPM) 50 (66 WPM) and 75 Baud (100 WPM)
STOP Bit Control
There are two possible settings, 1.5 or 2.0 stop bits. This essentially sets the delay between letters sent in
Baudot mode.
Diddle Control
If Diddle is enabled, a constant stream of LTRS or blanks will fill idle transmission time as soon as a leading
bracket
[
is entered on the keyboard. It will stay active until a trailing bracket
]
is entered. A user always
starts a stream by starting with a leading bracket. They can then type at leisure knowing that diddle will fill
the empty space. Either LTRS or blanks will be sent as specified. There are three choices, Diddle Off, Diddle
with LTRS, and Diddle with Blanks). Most ops send a Baudot blank (0x00) for the diddle, but LTRS (0x1F) is
often used instead.