Jim,
Just sitting there - It always happens and only once, after that
everything is stable. My DDS has the heat sink (ECO-ed) so I still
suspect it is just an unusual behavior of my oscillator.
Kurt KC9FOL
Jim Lux wrote:
At 10:00 AM 1/29/2006, Kurt Vangsness wrote:
John,
I see similar behavior. From a cold start I'm off freq by hundreds of HZ
and after something like 2 to 3 minutes there is a sudden shift and
everthing is on freq and relatively stable. I've always been surprised
that it is such a sudden shift and not a gradual shift as the osc.
warms up.
A sudden shift?
Are you commanding anything, or is it just sitting there?
On my radios, sudden shifts were almost always due to the the
temperature of the DDS. If it gets too hot, it stops responding to
the commands correctly. Doesn't outright fail, but seems that some
bits don't get through. My radios are the older heatsink-less
varieties, and even a small air flow (from one of those tiny 1U high
40mm fans) entirely fixes the problem.
Jim, W6RMK
