SCS PTC-IIex, Manual

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5 PTC-Firmware
transparency in combination with PR programs allows the usage of binary transfer
protocols via PACTOR.
Using the WA8DED hostmode the PTC-IIex sends and receives data in PACTOR
absolutely binary data transparent. The data transparency certainly includes all characters
being attached to special functions in the terminal mode. The consequence is:
Using the hostmode the CHANGEOVER character or the BREAKIN character does not
cause any change of direction at the PACTOR connection anymore. (Keyboard macros,
e.g. in
GP , which generate these special characters are ineffective!). In the hostmode for
changeovers the commands
%O
or
%I
have to be used.
5.13 Audio Functions
For special processing and filtering of Audio signals (Audio from the Transceiver) the
PTC-IIex presents its own submenu - the so called Audio-Denoiser menu,
aud:-
menu.
The PTC-IIex is thus also suitable for SSB operation (automatic notch filter) and for CW
listening (Automatic peak-filter, CW-filter) and has very useful options. The Audio is
presented to the PTC as usual via PIN 4 of the 8 PIN HF radio connector, so that no
changes compared with normal RTTY/PACTOR operation are required. The processed or
filtered signal is presented at PIN 1 of the HF radio connector. The maximum level of this
output AF signal is 500 mVpp. For the first test, a 600
Ω
earphone can be connected
directly to the AF signal from the PTC-IIex. Usually, however, a small AF amplifier with
volume control should be used, which enables comfortable loudspeaker operation. The
very high computing capacity of the PTC-IIex is shown to be very advantageous for the
Audio processing algorithm. In comparison to the usual simpler and cheaper Audio
Denoiser units, several times as much computing power can be used to optimize the
result.
All functions of the
aud:-
menu that process the AF input signal use a 4-stage signal level
matching (22 dB adapting range) for the 16-Bit A/D converter in order to keep the
quantization effect low and to provide a large effective dynamic range. The PTC-IIex
therefore adjusts itself in stages automatically to the average signal level delivered from
the transceiver. A complete description of the
AUdio
commands set is given in section
Audio (refer to chapter 7 , page 91 ).
5.14 The hostmode
The PTC-IIex supports the WA8DED hostmode and an
SCS
specific extension, the CRC
Hostmode. For detailed information about the hostmode and the hostmode commands
refer to chapter
5.14 , page 35 . Pay attention to the explanations concerning the
TNC
command (refer to chapter 6.95 , page 81 ).
Here you find some important details for the hostmode and PACTOR cooperation.
To make PACTOR accessable from the hostmode, one of the hostmode channels can be
reserved for PACTOR operation. On this reserved channel a connect or disconnect
command of the hostmode program is effective on the short wave port of the PTC-IIex
and establishes a PACTOR connection or terminates it. If the PACTOR listen mode is
activated, incoming text will also be displayed in this channel and not in the monitor-
screen of the hostmode program.
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