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AMTOR Operation
With your KAM Plus, several modes of AMTOR operation are possible. Each AMTOR station is iden-
tified by a SELCAL (Selective Call) which is derived from your amateur callsign. The accepted prac-
tice in AMTOR is to use the first letter of your callsign and the last three letters of your callsign as
your AMTOR SELCAL. The KAM Plus will automatically assign your SELCAL using this method, but
you may change it by using the MYSELCAL command. In addition, the KAM Plus supports a 7-char-
acter SELCAL and generates a unique SELCAL for this mode from your callsign. The KAM Plus will
accept a link from another station calling you with either the 4-character or 7-character SELCAL.
Mode A AMTOR is called ARQ and is a connected mode allowing you to communicate with just
ONE other station at a time. The two stations send data back and forth at a rapid interval (every
450 milliseconds); therefore, this mode requires radios capable of switching from receive to trans-
mit and back to receive very rapidly. Relay-switched radios typically cannot operate Mode A AM-
TOR.
Mode B AMTOR is called FEC. This mode broadcasts continually, allowing simultaneous reception
by several stations. Since there is no back-and-forth transmission between stations, the switching
speed of the radios is not significant and all SSB radios will operate Mode B AMTOR. A subset of
Mode B AMTOR is called SELFEC – Selective FEC. In this mode, stations using the proper SELCAL
on their equipment automatically receive and you will only receive transmissions that also send the
correct SELCAL.
The third mode of AMTOR operation is a listen only mode, called LAMTOR. In this mode, you can
monitor two stations communicating with each other using Mode A AMTOR; you can even monitor
SELFEC transmissions that do not contain your SELCAL.
Mode A (ARQ) Operation
To operate Mode A AMTOR, you must first be sure you are in the Command Mode (cmd:). Type
AMTOR and press return. This places your KAM Plus in the AMTOR Standby Mode and you will see
the message <AMTOR STANDBY> on your terminal. In this mode you can monitor other stations
transmitting FEC (calling CQ), transmit FEC allowing you to call CQ, and respond to a Mode A link
request from another station. NOTE: You will not be able to monitor or transmit FEC from this
mode if ARQBBS is ON. If AUTOSTRT is ON, you will only copy SELFEC transmissions from other
stations if they contain your SELCAL in the transmission.
Calling CQ
To call CQ from this mode, type [Ctrl-C][T]. The KAM Plus keys your transmitter, the bargraph on
the KAM Plus goes dark, and the HF transmit LED (red LED at the far left of the KAM Plus) lights.
Now type your CQ message on the keyboard. A typical CQ message would be like the following:
CQ CQ CQ CQ DE WK5M WK5M (WWKM)
CQ CQ CQ CQ DE WK5M WK5M (WWKM)
CQ CQ CQ CQ DE WK5M WK5M (WWKM)
SELCAL: WWKM WWKM PSE K K K
After you've finished typing your CQ, type [Ctrl-C][E], instructing the KAM Plus to return to the AM-
TOR Standby mode. After all of the data has been transmitted, the KAM Plus will send the
<AMTOR STANDBY> message to your terminal and enter the Standby mode; the KAM Plus is now
able to respond to any station that attempts to link to you.
When a station links to you, your KAM Plus becomes the Information Receiving Station (IRS), and
the station that called you is the Information Sending Station (ISS). When the other station keys in
data, it will be transmitted to you and will appear on your screen. At some point in the conversa-
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