SCS PTC-IIex, Руководство пользователя

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6 Commands
If
AP
is set to 200, the PTC-IIex will never set the PSK output level below 200 mV. That
means that with a PSKA value of 140 (setting of the maximum PSK amplitude value,
refer to the
PSKAmpl
command, chapter 6.73 , page 69 ) and an
AP
of 200 the power
never will be reduced.
If the
PSKA
value is 140 and the
AP
is 70, e.g. the amplitude of the
PSKA
output signal of
the PTC-IIex will at a maximum be reduced by the factor 2 (maximum power reduction
by the factor 4).
The setting of the minimum amplitude allows a limitation of the auto power adjustment
range. This is sometimes obvious and necessary: Some transceiver only operate proper in
a limited power range. This can also increase the average throughput in rapidly
fluctuating channels.
In most of all cases the auto power can be switched on with
APower
1.
6.5 AQrg
Default setting: 1
Parameter: 0 Automatic carrier frequency compensation switched off.
1 Automatic carrier frequency compensation for PTC-IIex switched on.
The PTC-IIex uses two totally separate compensation methods for frequency error during
DPSK operation. The phase error on receive caused by frequency offset is always
relatively quickly compensated, switching off this function, which is essential for PSK
operation, is not possible.
AQrg
1 activates the second, additional compensation method:
The PTC-IIex pulls the two carrier frequencies of the modems (DSP) slowly towards the
set value. This, in contrast to the pure error phase compensation, also influences the
focussing indicator (The QRG-Display LED, which slides slowly back to the center
position). To prevent completely drifting away from the chosen frequency, the PTC-IIex
uses Master/Slave tracking. This means that the Slave station ( Called by the master
station) only adjusts its receive frequency, but the Master station (initiating the contact)
adjusts synchronously both the RX and TX frequencies (relative to the measured offset of
the RX frequency to the set value). Depending on the cycle length and actual signal ratio,
as well as on the size of the QRG error variegates the frequency adjustment speed. On
average it tends to be around 15 Hz per minute.
6.6 ARX
Default setting: 1
Parameter: 0 AMTOR phasing disabled.
1 AMTOR phasing enabled.
With
ARX
0 it is not possible to obtain an AMTOR connect in the standby mode. Also
the reception of AMTOR FEC and NAVTEX is disabled.
With
ARX
1, the
SCS
-PTC reacts on an AMTOR connect attempt in the standby mode.
Reception of AMTOR FEC and NAVTEX is enabled, provided that the
BC
parameter is
set to 1.
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