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Hints for G-TOR Operation
If you choose to use the FSK mode of your transceiver, you must connect the FSK output from the
KAM Plus (Pin 5) to the FSK input of your radio. The actual tones transmitted are controlled by
your radio in this mode. Most radios use a mark frequency of 2125 Hz and a space of 2295 Hz.
These are the tones used by the KAM Plus when the SHIFT command is set to 170, 425 or 850. If
you have set your radio to operate with different tones, you must set the SHIFT command to
MODEM and set the MARK and SPACE commands in the KAM Plus to match your radio selection.
When you are linked to another station and you want to break the link, you should use the
[Ctrl-C][A] directive. This directive will attempt to send the proper QRT sequence to the other sta-
tion, but if the KAM Plus receives an invalid response sequence (unrecognized CS code) it will im-
mediately return to G-TOR Standby and discard any pending data. If you attempt to break the link
with the [Ctrl-C][X] directive, then the KAM Plus will attempt the QRT sequence, but will only re-
turn to PACKET Mode after receiving the proper acknowledgment (CS code) or after GTERRS at-
tempts to break the link. This could take a long time.
When you attempt to link to a nearby station, it is possible that the transceivers (yours and the
other station) may not switch fast enough to permit a link to occur. In this case, we suggest that
both stations set the TXDTOR command to a higher value (try 7, 8, or 9). This has been proven to
allow links on very short paths with very slow radios.
If you use an external power amplifier with your HF transceiver, you may set a time delay to key
your transmitter before the audio is sent to your radio by using the PREKEY command. This will al-
low your amplifier to turn on before full transmitter power is applied. You may also set the POST-
KEY command to stop the transmit audio before releasing the PTT line to your transceiver. (Note
that PREKEY adds delay time before data begins.)
NOTE: Do not change TXDTOR, PREKEY or POSTKEY values while you are linked. This is only pos-
sible with Host mode programs, but changing these values while linked will cause the link to fail.
Binary Files and G-TOR
The G-TOR Mode provides complete data transparency, allowing binary file transfers between
G-TOR stations. The ability to send and receive binary files in this mode will depend on the termi-
nal program you are using. Since G-TOR provides complete error detection and correction, binary
files should be send in a raw data mode – that is, no error correction protocol (such as X-modem)
needs to be used from your terminal program.
Host mode programs simply include the raw binary data in the data stream, however if you are us-
ing a standard telephone communications program, it is possible to allow the KAM Plus to send
raw binary data. To do this, once you are linked to another station in G-TOR and wish to send a
raw binary file, type the [Ctrl-C][B] directive. This places the KAM Plus in a data transparent mode,
allowing ALL characters to be transmitted from the computer.
NOTE: When you have done this, there are no special characters recognized by the KAM Plus, and
there are no directives available. This means that typing [Ctrl-C][E], for instance, will NOT cause a
changeover, it will simply transmit the [Ctrl-C] character and the E to the other station. To exit this
data transparency mode, you MUST send a modem break signal. Most telephone communications
programs support this feature. (Procomm Plus, for instance, sends a modem break when you press
[ALT-B]). If your communications program does not support the modem break, you will NOT be
able to leave the data transparency mode.
The KAM Plus will automatically exit data transparency if the other station disconnects from you, or
at any time your KAM Plus leaves the linked state (due to errors or retries).
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