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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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Old July 19th 03, 08:16 AM
Rob Judd
 
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The ARRL Handbook (any edition).
The Art of Electronics.

Two of the best basic electronics books ever written

Rob


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

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Old July 19th 03, 12:42 PM
Paul Burridge
 
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On Fri, 18 Jul 2003 07:16:07 -0700, W7TI wrote:

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.


0 hz is hardly a 'frequency.'
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Old July 19th 03, 12:42 PM
Paul Burridge
 
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On Fri, 18 Jul 2003 14:05:06 +0200, "Tom" wrote:

Leigh W3NLB wrote:
12 MHz is easy. 0 MHz is really difficult.


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.

Big thanks to all other people who gave me good starting points. I was
thinking about some CMOS devices, but most of them are square output.


Feed the square output to a coil+capacitor in parallel and you'll get
a sine wave. Tune the this 'tank' circuit for harmonics of the
funamental and you can double, triple, quadruple and so on the
original square wave's frequency.
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Old July 19th 03, 04:56 PM
Tom
 
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Paul Burridge wrote:
Feed the square output to a coil+capacitor in parallel and you'll get
a sine wave. Tune the this 'tank' circuit for harmonics of the
funamental and you can double, triple, quadruple and so on the
original square wave's frequency.


Thank you Paul! This is a good hint. Can you tell me in which book did you
learn it? I would really like to get into this stuff.

Regards
Tom




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Old July 19th 03, 04:59 PM
Tom
 
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Rob Judd wrote:
The ARRL Handbook (any edition).


On its way here...

The Art of Electronics.


I have this one and im not too happy with oscillator chapter. However, this
is still one of the best books i've seen.

Regards
Tom


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Old July 19th 03, 05:20 PM
Ken Knox
 
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On Sat, 19 Jul 2003 06:47:32 -0700, W7TI wrote:

On Sat, 19 Jul 2003 12:42:02 +0100, Paul Burridge
wrote:

0 hz is hardly a 'frequency.'


__________________________________________________ _______

Of course zero Hz is a frequency. Have you ever had a checkbook balance
of zero? Is that not a balance? :-)


Frequently!!! :-)


--
Ken Knox
N1JRO


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Old July 19th 03, 08:14 PM
Roy Lewallen
 
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A perfectly symmetrical square wave doesn't contain any even harmonics.
For best results when using this technique to generate even harmonics,
the square wave needs to have a longer "on" period than "off" period or
vice-versa.

Roy Lewallen, W7EL

Paul Burridge wrote:

Feed the square output to a coil+capacitor in parallel and you'll get
a sine wave. Tune the this 'tank' circuit for harmonics of the
funamental and you can double, triple, quadruple and so on the
original square wave's frequency.


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Old July 19th 03, 08:37 PM
R J Carpenter
 
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"Tom" wrote in message
...
Paul Burridge wrote:
Feed the square output to a coil+capacitor in parallel and you'll get
a sine wave. Tune the this 'tank' circuit for harmonics of the
funamental and you can double, triple, quadruple and so on the
original square wave's frequency.


Thank you Paul! This is a good hint. Can you tell me in which book did you
learn it? I would really like to get into this stuff.


IMO you are being led astray. I don't see why the emphasis on frequency
multiplication. It is fairly simple to make an LC oscillator cover a 2 to 1
frequency range, or even 3 to 1. That could mean 4 to 12 MHz in one tuning
range and 1.3 to 4 in another. The problem is lower frequencies. These days
it is hard to find a large-enough variable capacitor for operation down in
the few-hundreds of kilohertz range, let alone lower.

I know of only two ways that will cover the whole zero to 12 MHz range
without bandswitching or switched filters.

One is the direct digital synthesizer DDS. Single chip DDS units are
available [Analog Devices Inc] fairly cheaply, but they are tiny and require
a computer or equivalent to control them. You get "perfect" frequency
accuracy and stability and a sine-wave output.

The other is a beat-frequency method with two oscillators operating
considerably above 12 MHz. One crystal controlled, the other knob
controlled tuning from the crystal frequency to 12 MHz higher. Feed them
into a double-balanced mixer (MiniCircuits) followed by a low-pass filter
that passes 0 to 12 MHz, and strongly rejects the crystal osc frequency and
all higher. One knob, no switching, no computer needed for control - but
also much poorer frequency accuracy and stability.


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Old July 19th 03, 10:01 PM
Hank Oredson
 
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"Leigh W3NLB" wrote in message
...
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.



I have a couple of those.
They put out significant power.

--

... Hank

Hank: http://horedson.home.att.net
W0RLI: http://w0rli.home.att.net


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