SCS PTC-IIex, Manual

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15 Basics
phase offset from the correct value for every packet, and thereby obtains a very reliable
measure of the optimum speed required.
Important: The PTC-IIex only switches to a higher speed if there is more data available
to be transmitted, than the actual speed could transmit.
15.4.4 CQ calls and broadcasts
As with PACTOR-I, a CQ call or broadcast is normally carried out with 100 Bd FSK
UNPROTO mode (see the
Unproto
command (refer to chapter 6.100 , page 84 ). Such
transmissions can be read by all PACTOR users. If, however, only those users with
Level-II systems should be addressed, then a DPSK-Unproto transmission can be chosen
(see the
Unproto
command. We recommend the Unproto-3 mode for a DPSK CQ call.
This is DBPSK with short packets, and has proved to be the most robust broadcast mode
under normal conditions.
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