Specifications

send the AAB message when another station requests your identity, and
then stop sending.
7.4.3 Operating AMTOR with Other Modem frequencies and Shifts
All Amateur (AMTOR) and commercial (SITOR) stations that we know of
use either 170 or 200 Hz shift FSK modems. Modem 2 (default) is
therefore the best choice for ARQ or FEC AMTOR use. The PK-900
allows other modems to be used in AMTOR should the need arise. The
following other modems may be selected with the MODEM command.
Radio Port 1 Modems
MODEM 1 AFSK Modem, 170 Hz shift, M 2125 Hz, S 2295 Hz, 45 bps
MODEM 2 AFSK Modem, 170 Hz shift, M 2125 Hz, S 2295 Hz, 100 bps
MODEM 3 AFSK Modem, 200 Hz shift, M 2110 Hz, S 2310 Hz, 45 bps
MODEM 4 AFSK Modem, 200 Hz shift, M 2110 Hz, S 2310 Hz, 100 bps
MODEM 5 AFSK Modem, 425 Hz shift, M 2125 Hz, S 2550 Hz, 100 bps
MODEM 6 AFSK Modem, 850 Hz shift, M 2125 Hz, S 2975 Hz, 100 bps
MODEM 7 AFSK Modem, 850 Hz shift, M 2125 Hz, S 1275 Hz, 100 bps
MODEM 10 AFSK Modem, 200 Hz shift, M 2110 Hz, S 2310 Hz, 300 bps
7.4.4 Speed Change Not Permitted
In accordance with FCC 97.69 and international regulations, AMTOR is
operated at 100 bauds. The PK-900 does not permit other speeds. For
that reason, Modems 1 and 3 are not recommended.
7.4.5 Echoing Transmitted Characters As Sent (EAS)
EAS has special significance in ARQ AMTOR. If EAS is ON, you will see
characters echoed to your screen only after your partner in the AMTOR
link, has validated the previous block. With EAS ON, the characters
appear on your screen three at a time.
o If the data scrolls across your monitor at an even rate, you can
assume that you have a good ARQ link.
o If the data hesitates or scrolls in "jerky" intermittent fashion,
that's generally a sign that the radio link is not very good.
o If the characters stop appearing on your monitor, the link is
failing or has failed. The LCD Status display will tell you this
by showing ERROR or REQUEST nearly continuously.
7.4.6 Sending Only Complete Words (WORDOUT)
Some AMTOR 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.
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