On 3/18/2012 4:32 PM, Antonio I0JX wrote:


"Jim Yanik" ha scritto nel messaggio
4...

"Antonio I0JX" wrote in
:

The frequency stability of my HP3312A function generator is poor, very
annoying for any practical use. I am trying to determine whether that
behavior is fairly normal for function generators, or my particular
unit has got a problem.

What is your experience on function generators frequency stability?

Thanks & 73

Tony
Rome, Italy



it depends on the clock source;
some generators use better,ovenized crystal timebases.
The HP synthesizers had an option for high stability timebases,ISTR.
or you can feed in an external timebase.
At TEK,I used to feed a HP3336 with the output from my WWVB receiver.


Statements like "frequency stability is bad or poor will get you nowhere.
What are your requirements for stability?
Under what conditions? Temperature variability, time variability,
noise??? At what frequency?
What is the stability you are MEASURING?
What is the stability spec of the generator?
Stability is a NUMBER, not a vague statement of dissatisfaction.

HP equipment of that vintage was typically near the better end of
performance for equipment of that vintage. But even HP equipment breaks.
Performance is usually better near the top end of the dial.
Just 'cause you can get 1000:1 range on the knob doesn't mean
you should.

OK, I looked up the spec. I can't find any reference in the spec
to frequency stability, other than it takes an hour for the frequency
to get within 5% of the dial setting.
That oughta tell you something.

In general, if your requirements contain the word "stability",
a function generator is a poor choice.