PK-232 MBX – OPERATING MANUAL AMTOR AND NAVTEX OPERATION
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CHAPTER 7 – AMTOR AND NAVTEX OPERATION
7.1 Overview
The PK-232 provides AMTOR operation in accordance with FCC Part 97.69 and CCIR Re-
commendations 476-2/476-3 and 625 for Mode A (ARQ) and Mode B (FEC) modes.
AMTOR is an adaptation of the SITOR system used in high-seas ship telex, which provides
error detection and correction.
AMTOR has two basic modes of operation, Mode A (ARQ - Automatic ReQuest for Reception)
and Mode B (FEC - Forward Error Correction).
o ARQ AMTOR is a handshaking protocol that allows only two stations to communicate
in a near error free fashion. You will hear a "chirp chirp" sound when you find two
stations conversing in ARQ.
AMTOR Mode A (ARQ) is the perhaps the most error-free method of getting mes-
sages through on HF when conditions are poor.
o FEC AMTOR is similar to Baudot RTTY and is used to call CQ or to carry on "round
table" contacts.
NAVTEX is a form of FEC AMTOR that is used to send Navigational bulletins and weather in-
formation primarily to ships at sea. Recently it has been adopted by the ARRL to send bulle-
tins to amateurs.
7.2 Where to Operate AMTOR
Before you can operate AMTOR, you must first know where the activity is. Most AMTOR op-
eration occurs on the 20-meter amateur between 14.065 and 14.085 MHz. AMTOR activity
can be found on the other HF amateur bands as well and is most often located between 65
and 90 kHz up from the bottom of the band as it is on 20 meters.
7.2.1 PK-232 AMTOR Parameter Settings
AMTOR is a bit more complex than Baudot or ASCII operation. AMTOR operating modes
require SELCALL (Selective Call) codes be entered before you can operate. There are two
SELCALLs you should enter.
7.2.2 Entering Your SELective CALling Code (MYSELCAL)
This unique character sequence contains four alphabetic characters that are derived from
your call sign. The PK-232 will automatically do this for you just by entering your amateur
callsign into the MYSELCAL command. If you are using an AEA PAKRATT program, follow
the instructions in the program manual for entering the command MYSELCAL.
If you are using a terminal, then Type MYSELCAL to load your SELCALL into the PK-232 as
shown below:
cmd:MYSELCAL N7ML
The PK-232 will tell you, MYSelcal now NNML
See the MYSELCAL command in the Command Summary if you are interested in more in-
formation on the translation process.
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