On 04/12/2018 22:11, David Fisher wrote:
I see “DT” values that range from about 0.0 to about 0.5 in my
system. Does this mean that, on average, my system clock is a little
slow, or a little fast?
I’ve searched the documentation. It explains that the column of
numbers show the difference between the signal and the system’s time,
but it doesn’t explain if the calculation is “signal – system” or
“system – signal”.
FWIW, my guess is that the value is “system – signal” and that the 200
or 300ms delta is due to signal processing delays in the radio. In my
case, 2 to 300 ms processing delays could be considered about right,
given the DSP filtering.
Thanks.
Dave / NX6D
The DT figure is the measured difference between your PC clock and the
sync of a decoded signal. A positive DT implies that the signal clock is
behind yours. Positive components of the DT are the sender's clock being
slow, and propagation delay. Also contributing are latencies including
audio buffering and other processing delay which can be at either of
both ends of the link and like propagation delay can only increase the
DT, net clock difference can contribute a negative or a positive DT
component.
73
Bill
G4WJS.
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