Specifications

6.5.3 Sending a Synchronous Idle or DIDDLE
Some RTTY users like to send an idle signal when no data is being
transmitted. To allow for this the PK-900 has the DIDDLE command.
See the Command Summary for more information.
6.5.4 Echoing Transmitted Characters As Sent (EAS)
Since Baudot RTTY at 45 baud is rather slow, some users like to know
when the characters are actually being sent. The EAS command when ON
echoes characters to the display only when they are sent over the air.
6.5.5 Sending Only Complete Words
Some RTTY users like to have their words sent out only when they are
complete. This allows the word you are currently typing to be edited
as long as you have not typed a <Space> character. Turning WORDOUT ON
activates this feature. See the Command Summary for more information.
6.5.6 Operating on the Wrong Sideband
In RTTY operation it is important to operate on the correct sideband,
otherwise other stations will not be able to copy your transmissions.
If you find another station operating on the wrong sideband, you can
reverse your receive sense with the RXREV command so you will not have
to change sidebands yourself.
Similarly, if someone tells you that you are on the wrong sideband,
you can correct your transmit signal sense with the TXREV command.
See the Command summary for more information on these commands.
6.5.7 Framing errors
Baudot and ASCII RTTY operation traditionally do not check for errors
and tend to be prone to receiving "garbage". The PK-900 has the
ability to check for framing errors on received characters which
can reduce the amount of "garbage" characters on the screen. To
reduce the amount of erroneous characters printed on the screen, turn
the command RFRAME ON (default OFF). See the Command Summary for a
complete description of the RFRAME command.
6.5.8 Unshift-On-Space (USOS)
The Unshift-On-Space (USOS Command) automatically changes the received
Baudot/Murray code characters to the LETTERS or lower case condition
after any "space" character is received.
When operating Baudot RTTY under poor conditions, a received LETTERS-
SHIFT character can be garbled, or another character can be wrongly
interpreted as a FIGURES-SHIFT character. Turning USOS ON helps
reduce reception errors under these conditions.
Some commercial, weather and utility RTTY services send groups of
numbers separated by spaces. When receiving such non-amateur signals,
USOS should be OFF to prevent displaying LETTERS-shifted characters
when the originator may have intended the data to be FIGURES-shifted.
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