I am fimilar with Colpitts, Harley, Clapps, Bulter, Piece oscillators?

Which configuration with JFET or BJT would yield the highest performance
and least jitter?

JJ

JJ wrote:
I am fimilar with Colpitts, Harley, Clapps, Bulter, Piece oscillators?

Which configuration with JFET or BJT would yield the highest performance
and least jitter?

JJ

AFAIK a well-designed Butler oscillator will have the lowest jitter, but
I doubt that you could do the "well designed" part without a lot of
bench work.

Any of the rest (considering a "Clapp" oscillator to mean a crystal
oscillator with rubbering) are good enough for communications work.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

As a generalization, I think that any circuit that excites the crystal's
series resonant mode will probably outperform a circuit that excites the
parallel resonant mode, because the series resonance is higher Q and is less
affected by external influences.

Joe
W3JDR


"Tim Wescott" wrote in message
...
JJ wrote:
I am fimilar with Colpitts, Harley, Clapps, Bulter, Piece oscillators?

Which configuration with JFET or BJT would yield the highest performance
and least jitter?

JJ

AFAIK a well-designed Butler oscillator will have the lowest jitter, but I
doubt that you could do the "well designed" part without a lot of bench
work.

Any of the rest (considering a "Clapp" oscillator to mean a crystal
oscillator with rubbering) are good enough for communications work.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

On Fri, 17 Feb 2006 10:21:19 GMT, "W3JDR" wrote:

As a generalization, I think that any circuit that excites the crystal's
series resonant mode will probably outperform a circuit that excites the
parallel resonant mode, because the series resonance is higher Q and is less
affected by external influences.

Joe, a minor issue.

Frerking,"Crystal Oscillator Design and Temperature Compensation" (and
a lot of other folks) says the Q of the crystal is: Q = Xl / R,
where Xl is the motional inductance and R is the ESR. Thus the Q of
the -crystal- is not a function of the mode of operation. Short of
drastically changing R, the crystal Q is unaffected by external
circuitry.

If we speak of overall -circuit- Q then that is a different can of
worms.



Joe
W3JDR


"Tim Wescott" wrote in message
...
JJ wrote:
I am fimilar with Colpitts, Harley, Clapps, Bulter, Piece oscillators?

Which configuration with JFET or BJT would yield the highest performance
and least jitter?

JJ

AFAIK a well-designed Butler oscillator will have the lowest jitter, but I
doubt that you could do the "well designed" part without a lot of bench
work.

Any of the rest (considering a "Clapp" oscillator to mean a crystal
oscillator with rubbering) are good enough for communications work.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

"Thus the Q of
the -crystal- is not a function of the mode of operation."
------------------------------

Wes,

If you're speaking of the Q of the crystal's inherent series resonance, then
you're right. However, most crystal oscillator circuits that we typically
see in common use operate in the parallel resonant mode, which isn't a
crystal resonance at all. It's the frequency at which the crystal's net
inductive reactance resonates the parallel combination of holder capacitance
and circuit capacitance. As such, it's quite affected by the circuit around
the crystal. When the crystal is operated in a parallel resonant mode as
described, the Q of the overall resonant circuit is much lower than the
crystal's resonant Q.

Joe
W3JDR

Tim Wescott wrote:
JJ wrote:
I am fimilar with Colpitts, Harley, Clapps, Bulter, Piece oscillators?

Which configuration with JFET or BJT would yield the highest performance
and least jitter?

JJ

AFAIK a well-designed Butler oscillator will have the lowest jitter, but
I doubt that you could do the "well designed" part without a lot of
bench work.

Any of the rest (considering a "Clapp" oscillator to mean a crystal
oscillator with rubbering) are good enough for communications work.

http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

FWIW, ADI recommends a Butler oscillator for use with their DDS chips,
for minimum jitter.

Leon

JJ wrote:

I am fimilar with Colpitts, Harley, Clapps, Bulter, Piece oscillators?

Which configuration with JFET or BJT would yield the highest performance
and least jitter?

JJ



Go get a commercial oscillator. They cost 3 to 10 US $...
Yeahhh, sure, square wave... Fixoit it and you know what you can exoect...
No more but no less!

cheers

Dan / M0DFI

....it's Colpitts, Hartley, Clapp,Butler and Pierce!
go with Butler since it has the crystal inserted between points of low
impedance, it actually boosts the Q of the crystal above the unloaded
Q. this Q is ths single most important source of jitter and attendant
phase noise.
Saandy 4Z5KS




JJ wrote:
I am fimilar with Colpitts, Harley, Clapps, Bulter, Piece oscillators?

Which configuration with JFET or BJT would yield the highest performance
and least jitter?

JJ

On 22 Feb 2006 07:31:43 -0800, "Saandy , 4Z5KS"
wrote:

[snip]

it actually boosts the Q of the crystal above the unloaded Q.

By what magic does it do this?

"Saandy , 4Z5KS" wrote in
oups.com:

...it's Colpitts, Hartley, Clapp,Butler and Pierce!
go with Butler since it has the crystal inserted between points of low
impedance, it actually boosts the Q of the crystal above the unloaded
Q. this Q is ths single most important source of jitter and attendant
phase noise.
Saandy 4Z5KS
Good grief I wrote that rather late at night.
Have you seen a simple Butler cct using JFETS? The ARRL one uses a
transformer which I rather not use.

JJ