On Tue, 24 Feb 2004 16:02:23 GMT, the renowned "Harold E. Johnson"
wrote:


You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator".

Alternatively, take a look at the Butler design by John Stephensen in
November/December 1999 QEX. He explains clearly why folks ever had problems
with Butlers and better yet, how to cure them. I've used this circuit
(without the Varactor tuning) on 9th overtone oscillators using hound dog
crystals.
W4ZCB

What's a "hound dog crystal"?

How to deal with butlers:
http://etext.library.adelaide.edu.au...chapter41.html


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

What's a "hound dog crystal"?

How to deal with butlers:
http://etext.library.adelaide.edu.au...chapter41.html


Best regards,
Spehro Pefhany



Thanks Spehro. Delightful! I wondered what it had to do with things until
down the page a bit.

Sorry for the lack of definition, I was referring to crystals not
specifically treated to enhance overtone operation. When a manufacturer
makes a crystal for overtone use, he/she treats it to suppress spurious
responses close by the desired overtone so the crystal "likes" to operate
properly. An untreated crystal often will have those responses and oscillate
on one or more of them instead of the desired frequency unless the feedback
and tuned circuit are carefully managed to ignore them. The higher
impedance of Stephensens schematic make that a bit easier to do.

Regards

W4ZCB

What's a "hound dog crystal"?

How to deal with butlers:
http://etext.library.adelaide.edu.au...chapter41.html


Best regards,
Spehro Pefhany



Thanks Spehro. Delightful! I wondered what it had to do with things until
down the page a bit.

Sorry for the lack of definition, I was referring to crystals not
specifically treated to enhance overtone operation. When a manufacturer
makes a crystal for overtone use, he/she treats it to suppress spurious
responses close by the desired overtone so the crystal "likes" to operate
properly. An untreated crystal often will have those responses and oscillate
on one or more of them instead of the desired frequency unless the feedback
and tuned circuit are carefully managed to ignore them. The higher
impedance of Stephensens schematic make that a bit easier to do.

Regards

W4ZCB

On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK"
wrote:

You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator". I have seen it called other
names as well. Basically, what you do is first build an LC
(ie no xtal) Colpitts oscillator and tune it to the crystal frequency
you want to eventually use.
[snip]

Sounds like an oscillator that I've used since the '60's for my G-jobs
(you know, the ones that *have* to work, 'cause they're for me :).

See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website.

I've never been able to get any custom IC customers to use it, since
it takes three pins, but it works, period, no messy matching issues,
even handles overtone modes.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK"
wrote:

You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator". I have seen it called other
names as well. Basically, what you do is first build an LC
(ie no xtal) Colpitts oscillator and tune it to the crystal frequency
you want to eventually use.
[snip]

Sounds like an oscillator that I've used since the '60's for my G-jobs
(you know, the ones that *have* to work, 'cause they're for me :).

See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website.

I've never been able to get any custom IC customers to use it, since
it takes three pins, but it works, period, no messy matching issues,
even handles overtone modes.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Tue, 24 Feb 2004 12:26:22 -0700, Jim Thompson
wrote:

On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK"
wrote:

You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator". I have seen it called other
names as well. Basically, what you do is first build an LC
(ie no xtal) Colpitts oscillator and tune it to the crystal frequency
you want to eventually use.
[snip]

Sounds like an oscillator that I've used since the '60's for my G-jobs
(you know, the ones that *have* to work, 'cause they're for me :).

See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website.

I've never been able to get any custom IC customers to use it, since
it takes three pins, but it works, period, no messy matching issues,
even handles overtone modes.

...Jim Thompson

Aha! I just noted from Paul's post that "my" oscillator is called a
two-transistor Butler. Wonder when that was conceived? I've been
using the my direct-coupled version for 40 years.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Tue, 24 Feb 2004 12:26:22 -0700, Jim Thompson
wrote:

On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK"
wrote:

You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator". I have seen it called other
names as well. Basically, what you do is first build an LC
(ie no xtal) Colpitts oscillator and tune it to the crystal frequency
you want to eventually use.
[snip]

Sounds like an oscillator that I've used since the '60's for my G-jobs
(you know, the ones that *have* to work, 'cause they're for me :).

See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website.

I've never been able to get any custom IC customers to use it, since
it takes three pins, but it works, period, no messy matching issues,
even handles overtone modes.

...Jim Thompson

Aha! I just noted from Paul's post that "my" oscillator is called a
two-transistor Butler. Wonder when that was conceived? I've been
using the my direct-coupled version for 40 years.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Tue, 24 Feb 2004 17:45:51 GMT, "Harold E. Johnson"
wrote:

Sorry for the lack of definition, I was referring to crystals not
specifically treated to enhance overtone operation. When a manufacturer
makes a crystal for overtone use, he/she treats it to suppress spurious
responses close by the desired overtone so the crystal "likes" to operate
properly. An untreated crystal often will have those responses and oscillate
on one or more of them instead of the desired frequency unless the feedback
and tuned circuit are carefully managed to ignore them.

The following link is worth checking out as an overview....

http://www.icmfg.com/crystaloscillatordata.html
--

The BBC: Licensed at public expense to spread lies.

On Tue, 24 Feb 2004 17:45:51 GMT, "Harold E. Johnson"
wrote:

Sorry for the lack of definition, I was referring to crystals not
specifically treated to enhance overtone operation. When a manufacturer
makes a crystal for overtone use, he/she treats it to suppress spurious
responses close by the desired overtone so the crystal "likes" to operate
properly. An untreated crystal often will have those responses and oscillate
on one or more of them instead of the desired frequency unless the feedback
and tuned circuit are carefully managed to ignore them.

The following link is worth checking out as an overview....

http://www.icmfg.com/crystaloscillatordata.html
--

The BBC: Licensed at public expense to spread lies.

Jim Thompson wrote:
On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK"
wrote:


You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator". I have seen it called other
names as well. Basically, what you do is first build an LC
(ie no xtal) Colpitts oscillator and tune it to the crystal frequency
you want to eventually use.

[snip]

Sounds like an oscillator that I've used since the '60's for my G-jobs
(you know, the ones that *have* to work, 'cause they're for me :).

See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website.

I've never been able to get any custom IC customers to use it, since
it takes three pins, but it works, period, no messy matching issues,
even handles overtone modes.

...Jim Thompson

This pdf schematic looks very similar, except for the crystal and emitter
part, to a circuit described in "Experimental Methods in RF Design" (p4.13).

The circuit is described as "worth building......to observe first hand just
what a noisy oscillator will sound like in a receiver".

Earlier in the same chapter it appears in figure 4.13 as a type of negative
resistance one port oscillator.

I can only assume that the changes and crystal (in the circuit shown in the
pdf) solve the problem of the "noisy" LC only configuration.

I mention it as I built it up last night and took it into work today in order
to have a look at the output on a spectrum analyser. Output was quite low at
-27dBm. Sadly the HP kit couldn't measure phase noise directly, and I didn't
have a good crystal oscillator to check it against.

We were uncertain regarding the configuration too, but my colleague worked out
that it had severe voltage limiting features and predicted the output swing
quite accurately before it was measured on a scope.

Last night I tried it with a number of inductors from the junk box and it
oscillated quite readily from 114MHz down to 5MHz. I quite like the use of a
non tapped L and only a single C. Shame about the phase noise :-(.

regards...

--Gary