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Old July 18th 03, 02:40 AM
Michael Black
 
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Leigh W3NLB ) writes:
On Thu, 17 Jul 2003 19:11:57 +0200, "Tom" wrote:

Hello

If anyone can recommend me a good book from which i will learn to construct
oscillator that for example covers range 0-12 MHz.

Thanks in advance!
Tom


12 MHz is easy. 0 MHz is really difficult.


73 de Leigh W3NLB

The workaround is to have a variable oscillator beating against a fixed
oscillator. So you have your variable oscillator going from 30 to 42MHz
(I just picked those out of my hat), a fixed oscillator running at 30
MHz, and a mixer fed with both oscillators. The output of the mixer will
be 0 to 12MHz (plus some other things).

Michael VE2BVW


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Old July 18th 03, 02:53 AM
Harold E. Johnson
 
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I need to get one of the MAX038EVKIT oscillator evaluation kits shown at

the website
below but can't check the price nor order it without being a logged-in

member, and
don't believe that would work out for a one piece hanm radio use purchase.

Where/how
can I just order a single unit?

Dick



Maxim has an enlightened purchasing policy and will sell at a small premium,
1 or 2 of anything in their product line direct.

W4ZCB


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Old July 18th 03, 02:53 AM
Harold E. Johnson
 
Posts: n/a
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I need to get one of the MAX038EVKIT oscillator evaluation kits shown at

the website
below but can't check the price nor order it without being a logged-in

member, and
don't believe that would work out for a one piece hanm radio use purchase.

Where/how
can I just order a single unit?

Dick



Maxim has an enlightened purchasing policy and will sell at a small premium,
1 or 2 of anything in their product line direct.

W4ZCB


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Old July 18th 03, 09:38 AM
Leon Heller
 
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"Tom" wrote in message
...
Hello

If anyone can recommend me a good book from which i will learn to

construct
oscillator that for example covers range 0-12 MHz.


A DDS chip like the Analog Devices AD9850 will give you something close to
that. It won't quite go down to 0 MHz, though. You could just switch it off,
of course.

Leon
--
Leon Heller, G1HSM

http://www.geocities.com/leon_heller


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Old July 18th 03, 09:38 AM
Leon Heller
 
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"Tom" wrote in message
...
Hello

If anyone can recommend me a good book from which i will learn to

construct
oscillator that for example covers range 0-12 MHz.


A DDS chip like the Analog Devices AD9850 will give you something close to
that. It won't quite go down to 0 MHz, though. You could just switch it off,
of course.

Leon
--
Leon Heller, G1HSM

http://www.geocities.com/leon_heller




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Old July 18th 03, 03:51 PM
Michael Black
 
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W7TI ) writes:
On Fri, 18 Jul 2003 14:05:06 +0200, "Tom" wrote:

If you read my original post again or at least the topic, it says 0-12 (not
0, 12) MHz. And that would mean something in the range between 0 and 12. I
don't remember when and WHERE i said that i need 0 MHz oscilator. The only
one who talks about 0 MHz osc is you.


__________________________________________________ _______

Perhaps English is a second language for you, but when you say 0-12 that
will be taken to mean those two frequencies and everything in between.

--
Bill, W7TI

And of course, even if such a full range oscillator was not intended
by the original poster, I'd say there often is a big difference between
oscillators in the KHz range and those in the MHz range. Obviously,
the concept of an oscillator doesn't change, but the specific design
does.

You can use resistors and capacitors to set the frequency down near
the audio range, and do your best to avoid coils down there due
to their size, while once you get into radio frequencies, one tends to
use coils for the frequency control element.

Time after time, I see people asking questions about oscillators,
and often they are coming to radio frequencies from an audio background.
So they think in terms of just scaling some favorite audio oscillator
up to radio frequencies, when a simpler solution would be to use an LC
oscillator.

Somewhere in this thread, the 8038's more recent spawn was mentioned.
Obviously, it will work over that full range, but I'm suspicious about
how good it will be at radio frequencies, as I would about any RC
oscillator. It seems a stretch to expect it to work as well at 12MHz
as at 10KHz.

Michael VE2BVW

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Old July 18th 03, 03:51 PM
Michael Black
 
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W7TI ) writes:
On Fri, 18 Jul 2003 14:05:06 +0200, "Tom" wrote:

If you read my original post again or at least the topic, it says 0-12 (not
0, 12) MHz. And that would mean something in the range between 0 and 12. I
don't remember when and WHERE i said that i need 0 MHz oscilator. The only
one who talks about 0 MHz osc is you.


__________________________________________________ _______

Perhaps English is a second language for you, but when you say 0-12 that
will be taken to mean those two frequencies and everything in between.

--
Bill, W7TI

And of course, even if such a full range oscillator was not intended
by the original poster, I'd say there often is a big difference between
oscillators in the KHz range and those in the MHz range. Obviously,
the concept of an oscillator doesn't change, but the specific design
does.

You can use resistors and capacitors to set the frequency down near
the audio range, and do your best to avoid coils down there due
to their size, while once you get into radio frequencies, one tends to
use coils for the frequency control element.

Time after time, I see people asking questions about oscillators,
and often they are coming to radio frequencies from an audio background.
So they think in terms of just scaling some favorite audio oscillator
up to radio frequencies, when a simpler solution would be to use an LC
oscillator.

Somewhere in this thread, the 8038's more recent spawn was mentioned.
Obviously, it will work over that full range, but I'm suspicious about
how good it will be at radio frequencies, as I would about any RC
oscillator. It seems a stretch to expect it to work as well at 12MHz
as at 10KHz.

Michael VE2BVW

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Old July 18th 03, 04:13 PM
Tom
 
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Michael Black wrote:
Somewhere in this thread, the 8038's more recent spawn was mentioned.
Obviously, it will work over that full range, but I'm suspicious about
how good it will be at radio frequencies, as I would about any RC
oscillator. It seems a stretch to expect it to work as well at 12MHz
as at 10KHz.


I agree. But on the other hand if you controll this 8038 with another PLL
synthesizer, i think the overall performance should be ok from 10 kHz to 12
MHz. I think that is the way how most of "pro stuff" works.


  #19   Report Post  
Old July 18th 03, 04:13 PM
Tom
 
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Michael Black wrote:
Somewhere in this thread, the 8038's more recent spawn was mentioned.
Obviously, it will work over that full range, but I'm suspicious about
how good it will be at radio frequencies, as I would about any RC
oscillator. It seems a stretch to expect it to work as well at 12MHz
as at 10KHz.


I agree. But on the other hand if you controll this 8038 with another PLL
synthesizer, i think the overall performance should be ok from 10 kHz to 12
MHz. I think that is the way how most of "pro stuff" works.


  #20   Report Post  
Old July 18th 03, 06:14 PM
JJ
 
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Leigh W3NLB wrote:
On Thu, 17 Jul 2003 19:11:57 +0200, "Tom" wrote:


Hello

If anyone can recommend me a good book from which i will learn to construct
oscillator that for example covers range 0-12 MHz.

Thanks in advance!
Tom



12 MHz is easy. 0 MHz is really difficult.


Zero MHz is real easy, just throw a capacitor, transistor,
resistor, tube, or any other electronic component on the bench.
There, an oscillator that oscillators at zero MHz.

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