Hi,
Agree. If you steer so you keep to be "off frequency" so you have plenty
of sawtooth you get better resolution. I've been pondering about maybe
write an article to illustrate the effect.
Cheers,
Magnus
On 04/03/14 23:45, Bob Camp wrote:
Hi
Be careful of what you wish for.
One way to “eliminate” the hanging bridge is to have the oscillator exactly on
frequency. That sounds fine. The problem is that you are always in the middle
of a bridge. The other way is to put the oscillator well off frequency. That
way you have lots of sawtooth action. There are lots of ways to get an
oscillator off frequency ….
Bob
On Mar 4, 2014, at 12:00 PM, Didier Juges <[email protected]> wrote:
What would be more interesting would be to adjust the temperature of the GPS
receiver's oscillator to eliminate the hanging bridges altogether, kind of like
Trimble does with the Thunderbolt, except that they do it directly instead of
indirectly. That may require to characterize the crystal oscillator to find out
if it has an appropriate control range over temperature.
Didier KO4BB
On March 3, 2014 6:51:54 PM CST, Charles Steinmetz <[email protected]>
wrote:
Chris wrote:
If do have an external frequency reference then the crystal itself
makes a good thermometer. So why not use THAT thermometer to
control the heat added by the resister. Such a system would respond
to changes in ambient temperature by adjusting the power in the
resister. We don't even have to care if the crystal's temp-co is
nonlinear because we are using a very small temperature range, so
small it looks linear.
I'll build it. Can you or anyone else subject a simple XCO
schematic? Hopefully SIMPLE. What I need is a design that can be
pulled down a few PPM so that I can raise it back with a bit of
heat. I will have to be kept at a temperer above the hottest it
will ever get inside the house, maybe 100F.
See below or attached (hopefully). L and C are chosen to resonate at
the crystal frequency with XC and XL in the general vicinity of 100
ohms to 1k ohms.
What you are proposing is a disciplined oscillator using the oven
setpoint as the control input.
Best regards,
Charles
------------------------------------------------------------------------
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other
things.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
