Thank you for all the hints.
I did several experiments, but was not able to get reliable injection
locking, several times the crystal jumped some 10-20Hz down, and
stayed there.
Think I have decided to just remove the 10MHz crystal and drive the
oscillator from a external source.
BR.
Thomas.
Den
In this case, it appears what you want is choice of two 10 MHz reference
sources, and not any frequency conversion. Instead of injection locking,
why not just switch between one or the other? It's quite simple to
externally drive the built-in oscillator in most ICs. You can make the
circuits
and a few
bi-polar transistors and seems to be a great solution instead of noisy odd-ball
dividers. Check it out.Bob, KE6F
-Original Message-
From: Bill Byrom
To: time-nuts
Sent: Sat, Mar 2, 2019 5:00 am
Subject: Re: [time-nuts] injection locking crystal oscillator
In the June 1946 issue
Am 02.03.19 um 17:02 schrieb jimlux:
Also, since injection locking is a case of coupled oscillators.. you
might be interested in this (freely downloadable):
Ulrich has a discussion of n promiscously coupled oscillators in [1].
In real life probably a debugging nightmare.
I'd like to
Hi
Where it gets nasty is when you realize that Q is just an approximation for the
phase slope of the
oscillator at the operating point…….
The Q of a crystal does not change as a function of frequency. The rate of
impedance change vs
frequency most definitely does. As you approach parallel
On 3/1/19 9:37 PM, Bill Byrom wrote:
In the June 1946 issue of "Proceedings of the I.R.E.", Robert Adler published "A Study of
Locking Phenomena in Oscillators*. I believe this is the first full study of injection locking. This
paper was so important that it was republished in the October 1973
In the June 1946 issue of "Proceedings of the I.R.E.", Robert Adler published
"A Study of Locking Phenomena in Oscillators*. I believe this is the first full
study of injection locking. This paper was so important that it was republished
in the October 1973 issue of "Proceedings of the IEEE".
I have five systems using injection locking. There are a few issues to
watch. If you inject at too high a level, any noise on the reference
will appear in the oscillator output. I use a 56 ohm resistor to
terminate the reference signal coax input, then a 100pF cap and a series
resistor
Hi
How close to frequency is the 10 MHz oscillator?
Is the crystal a fundamental?
The degree you can injection lock an oscillator is (as Danna notes) a bit
difficult
to predict. Your chances improve if the oscillator is low(er) Q. They also
improve
if it is tuned very close to frequency.
Hello Thomas,
What you ask is possible, but only if the native crystal oscillator
frequency is close enough to the signal from the GPSDO. You
may have to tune the oscillator yourself to get it to lock, and you
may or may not find that the result is predictable from day to day.
This would depend
Hello.
I have a device that consists of a PLL, that has as its reference a
10MHz crystal.
What I would like to do, is to inject this with 10MHz from a GPSDO,
when that is available, and to use the internal crystal when that is
not available.
Would it be feasible to just connect it to one leg of
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