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/

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

"Highest performance"? Is that output amplitude? Or minimum startup
time? Or startup reliability? Or lowest power requirement? Or what?

Jitter, that's a little easier to define but it's usually not the most
relevant parameter in radio. It is related to sideband and phase noise
and in fact cannot be completely decoupled from either.
tor :-)

Tim KA0BTD



Its not for a radio. I want to minimize the cycle to cycle variations in
timing and it should be simple enough to make with 1 or 2 transitors. So
not looking for NASA spec stuff, just reliable so it starts every time.

JJ

JJ wrote:
Its not for a radio. I want to minimize the cycle to cycle variations in
timing and it should be simple enough to make with 1 or 2 transitors. So
not looking for NASA spec stuff, just reliable so it starts every time.

Most reliable to start up you will find are the
crystal-oscillator-in-a-can. They also often spec some numbers with
respect to jitter.

The TCXO-in-a-can or VCTCXO-in-a-can made for telecom use are
particularly good bang-for-the-buck if you also want low jitter.

Tim.

JJ wrote:

"Highest performance"? Is that output amplitude? Or minimum startup
time? Or startup reliability? Or lowest power requirement? Or what?

Jitter, that's a little easier to define but it's usually not the most
relevant parameter in radio. It is related to sideband and phase noise
and in fact cannot be completely decoupled from either.


tor :-)


Tim KA0BTD





Its not for a radio. I want to minimize the cycle to cycle variations in
timing and it should be simple enough to make with 1 or 2 transitors. So
not looking for NASA spec stuff, just reliable so it starts every time.

JJ


Hi !

Any of those oscillators is OK if resonance circuit Q is kept high and
oscillation power in average low level.
High Q will guarantee easy and fast starting every time
Average low level keeps components cool and cycle to cycle variations
are reduced
Third important question is loading the oscillator.
High impedance FET buffer which is not galvanic ally connected to
oscillator is very good solution.
The gate of buffer FET can be provided with an "antenna" wire
collecting tiny energy from the oscillator resonance circuit.
This kind of loose coupling guarantees that effects of external
variations are minimized.

These principles also guarantee that buffer will amplify 1st order and
upper harmonics are powerfully reduced (in oscillator and in first buffer)
I have experienced superior results with these guidelines when
constructing LC oscillators

73, Risto OH2BT

Risto Tiilikainen wrote:

JJ wrote:

"Highest performance"? Is that output amplitude? Or minimum startup
time? Or startup reliability? Or lowest power requirement? Or what?

Jitter, that's a little easier to define but it's usually not the most
relevant parameter in radio. It is related to sideband and phase noise
and in fact cannot be completely decoupled from either.


tor :-)


Tim KA0BTD





Its not for a radio. I want to minimize the cycle to cycle variations
in timing and it should be simple enough to make with 1 or 2
transitors. So not looking for NASA spec stuff, just reliable so it
starts every time.

JJ


Hi !

Any of those oscillators is OK if resonance circuit Q is kept high and
oscillation power in average low level.
High Q will guarantee easy and fast starting every time
Average low level keeps components cool and cycle to cycle variations
are reduced
Third important question is loading the oscillator.
High impedance FET buffer which is not galvanic ally connected to
oscillator is very good solution.
The gate of buffer FET can be provided with an "antenna" wire
collecting tiny energy from the oscillator resonance circuit.
This kind of loose coupling guarantees that effects of external
variations are minimized.

These principles also guarantee that buffer will amplify 1st order and
upper harmonics are powerfully reduced (in oscillator and in first
buffer)
I have experienced superior results with these guidelines when
constructing LC oscillators

73, Risto OH2BT

HI !
Sorry . I read again your subject.
You were asking from crystal oscillators and I began to explain LC
oscillators
Risto

Risto Tiilikainen wrote in
:


Hi !

Any of those oscillators is OK if resonance circuit Q is kept high and
oscillation power in average low level.
High Q will guarantee easy and fast starting every time
Average low level keeps components cool and cycle to cycle variations
are reduced
Third important question is loading the oscillator.

73, Risto OH2BT
Good info thanks. What are other crystal series oscillators besides Butler
type?

JJ

If it oscillates it doesn't matter about the type of oscillator
circuit.

There's no need to worry yourself.

Performance all depends on the cut of the crystal which you have
already decided upon without giving it much thought.

Just connect it up in the most simple circuit and away you go.
----
Reg.

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