[time-nuts] Question on HP5359 Time Synthesizer
phk at phk.freebsd.dk
Mon Jun 23 04:01:36 EDT 2008
In message <A51FC2EBC4EC4E2EA0FD6FA84BC1630A at athlon>, "Ulrich Bangert" writes:
>There is however one annoying fact: If I use the instrument in
>"frequency" or "period" mode,
>[...] the frequency of the repetitive waveform will change and
>drift by an amount of some 100 Hz up to a few kHz so that my counter may
>read 996 kHz after a few minutes with the drift getting smaller over
>time as the device warms up.
You need to remember that in period/frequency mode the 5953 acts
like two independent one-shots biting each others tails, so the
frequncy you get depends not only on the precision of the pulses
they emit, but also on their trigger circuits getting it right.
In addition there is an analogue ramp based vernier delay generator
in each channel which in my experience is very temperature sensitive.
So if you want precision: let it warm up, and be very careful about
PS: I'd love a manual copy in PDF, the manual I have is a mess of
photocopies an wrong order etc.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
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