PK-232 MBX Operating Manual - N3UJJ

PK-232 OPERATING MANUAL
AMTOR AND NAVTEX OPERATION
CHAPTER 7
AMTOR AND NAVTEX OPERATION
7.1 Overview
The PK-232 provides AMTOR operation in accordance with FCC Part 97.69
and CCIR Recommendations 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 messages 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 information primarily to ships at sea. Recently
it has been adopted by the ARRL to send bulletins to amateurs.
7.2 Where to Operate AMTOR
Before you can operate AMTOR, you must first know where the activity
is. Most AMTOR operation 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
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