[OZAPRS] HF APRS

[Jack Chomley]

Ray,

The below feature is very useful too.

73  Jack  VK4JRC



Excerpt from SCS DSP Tracker Manual

Automatic TX-frequency correction at 300 Bd (A)FSK
%T (TX frequency tracking)
Default: 1
Possible parameters: 0, 1
Enables (1) or disables (0) the automatic 
frequency correction at 300 Bd FSK when transmitting.
Background: The very large tracking range of the 
FSK-demodulator (300 Bd FSK) provides
the possibility of easy and reliable receiving, 
but when transmitting, it can lead to not properly
hitting the receiving frequency of the distant 
station. (As the DSPTNC does not have a tuning
display, a quick and exact adjustment of the 
frequency at the transceiver is difficult.)
With activated automatic frequency tracking, the 
DSPTNC now checks a list of the 32 last
received callsigns in 300 Bd FSK mode (old 
“HF-Packet“). This list also contains the measured
frequency offsets of these stations. If the 
DSPTNC now sends a packet to one of these
callsigns from the list, the actual frequency 
offset will be considered, which means that the
receiving frequency of the distant station will 
exactly be hit – without the need to adjust the
transceiver respectively.
The maximum remaining frequency offset is +-12.5 Hz.

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