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Re: [time-nuts] 10 MHz Oscillator comparison part II

E
EWKehren@aol.com
Thu, Jan 13, 2011 10:17 AM

List
A while back I proposed the Austron 2110 circuit. No response. This is a
straight forward circuit with the only critical component the 5.0005 MHz
Xtal. I  am sure there is in this group enough expertise to find a source and if
enough  sign up a one time buy could bring the total assembly cost below $
50 PC board  included. With its 100 Hz output it may also turn into a simple
tool to  measure Allan Variance.
Bert Kehren

In a message dated 1/13/2011 3:54:38 A.M. Eastern Standard Time,
luciano.paramithiotti@hp.com writes:

^Well,  some time back I proposed a DMTD style front-end which mixes two
unequal  frequencies with a common oscillator into a common frequency. In a
second  ^stage it is mixed down by a second LO in more traditional DMTD  style.

^LO1 = (f1 + f2)/2
^IF1 = abs(f1 - LO1) = abs(f2 - LO2) =  abs(f1 - f2)/2
^LO2 = IF1 - IF2

^The IF1 filtering needs to filter  out the difference frequency and
supress the sum frequency. However, since  both sides of the chain will have same
^frequencies after first mixer,  correlation between the sides will create
smaller response differences unless  built very different.
^The mixer oscillator contribution for LO1 and LO2  will correlate between
the channels.

Magnus, can you write down a block  diagram?

Luciano
IZ5JHJ

Luciano P. S.  Paramithiotti

-----Original Message-----
From:  time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of  Magnus Danielson
Sent: giovedì 13 gennaio 2011 5.34
To:  time-nuts@febo.com
Subject: Re: [time-nuts] 10 MHz Oscillator comparison  part II

On 12/01/11 19:24, Bob Camp wrote:

Hi

If you have a random frequency like 7.352 MHz that neither divides or
multiplies to 10 MHz harmonic or sub harmonic, you can indeed mix the
signal to 10 MHz.

If you do so, you will need to filter the  outputs, since the mixing
spurs will mess up the input to the  multiplier.

If the generator you use for the mixing has more  noise or jitter than
the sources, that noise is likely to  de-correlate unless the chains
are absolutely identical. Since they  multiply to two different
frequencies, they really can't be  identical. Net result is your
measurement is messed up by the noise  of the generator.

Well, some time back I proposed a DMTD style  front-end which mixes two
unequal frequencies with a common oscillator into a  common frequency. In a
second stage it is mixed down by a second LO in more  traditional DMTD style.

LO1 = (f1 + f2)/2
IF1 = abs(f1 - LO1) =  abs(f2 - LO2) = abs(f1 - f2)/2
LO2 = IF1 - IF2

The IF1 filtering  needs to filter out the difference frequency and supress
the sum frequency.  However, since both sides of the chain will have same
frequencies after first  mixer, correlation between the sides will create
smaller response differences  unless built very different.
The mixer oscillator contribution for LO1 and  LO2 will correlate between
the  channels.

Cheers,
Magnus


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List A while back I proposed the Austron 2110 circuit. No response. This is a straight forward circuit with the only critical component the 5.0005 MHz Xtal. I am sure there is in this group enough expertise to find a source and if enough sign up a one time buy could bring the total assembly cost below $ 50 PC board included. With its 100 Hz output it may also turn into a simple tool to measure Allan Variance. Bert Kehren In a message dated 1/13/2011 3:54:38 A.M. Eastern Standard Time, luciano.paramithiotti@hp.com writes: ^Well, some time back I proposed a DMTD style front-end which mixes two unequal frequencies with a common oscillator into a common frequency. In a second ^stage it is mixed down by a second LO in more traditional DMTD style. ^LO1 = (f1 + f2)/2 ^IF1 = abs(f1 - LO1) = abs(f2 - LO2) = abs(f1 - f2)/2 ^LO2 = IF1 - IF2 ^The IF1 filtering needs to filter out the difference frequency and supress the sum frequency. However, since both sides of the chain will have same ^frequencies after first mixer, correlation between the sides will create smaller response differences unless built very different. ^The mixer oscillator contribution for LO1 and LO2 will correlate between the channels. Magnus, can you write down a block diagram? Luciano IZ5JHJ Luciano P. S. Paramithiotti -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Magnus Danielson Sent: giovedì 13 gennaio 2011 5.34 To: time-nuts@febo.com Subject: Re: [time-nuts] 10 MHz Oscillator comparison part II On 12/01/11 19:24, Bob Camp wrote: > Hi > > If you have a random frequency like 7.352 MHz that neither divides or > multiplies to 10 MHz harmonic or sub harmonic, you can indeed mix the > signal to 10 MHz. > > If you do so, you will need to filter the outputs, since the mixing > spurs will mess up the input to the multiplier. > > If the generator you use for the mixing has more noise or jitter than > the sources, that noise is likely to de-correlate unless the chains > are absolutely identical. Since they multiply to two different > frequencies, they really can't be identical. Net result is your > measurement is messed up by the noise of the generator. Well, some time back I proposed a DMTD style front-end which mixes two unequal frequencies with a common oscillator into a common frequency. In a second stage it is mixed down by a second LO in more traditional DMTD style. LO1 = (f1 + f2)/2 IF1 = abs(f1 - LO1) = abs(f2 - LO2) = abs(f1 - f2)/2 LO2 = IF1 - IF2 The IF1 filtering needs to filter out the difference frequency and supress the sum frequency. However, since both sides of the chain will have same frequencies after first mixer, correlation between the sides will create smaller response differences unless built very different. The mixer oscillator contribution for LO1 and LO2 will correlate between the channels. Cheers, Magnus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
E
ehydra
Thu, Jan 13, 2011 4:48 PM

Hello all!

I'm new here. What is the simplest way to make all the older messages
appear in my local email program? So I can local search for topics.

I'm using Thunderbird.

Thanks!

regards -
Henry

EWKehren@aol.com schrieb:

List
A while back I proposed the Austron 2110 circuit. No response. This is a
straight forward circuit with the only critical component the 5.0005 MHz
Xtal. I  am sure there is in this group enough expertise to find a source and if
enough  sign up a one time buy could bring the total assembly cost below $
50 PC board  included. With its 100 Hz output it may also turn into a simple
tool to  measure Allan Variance.
Bert Kehren

Hello all! I'm new here. What is the simplest way to make all the older messages appear in my local email program? So I can local search for topics. I'm using Thunderbird. Thanks! regards - Henry EWKehren@aol.com schrieb: > List > A while back I proposed the Austron 2110 circuit. No response. This is a > straight forward circuit with the only critical component the 5.0005 MHz > Xtal. I am sure there is in this group enough expertise to find a source and if > enough sign up a one time buy could bring the total assembly cost below $ > 50 PC board included. With its 100 Hz output it may also turn into a simple > tool to measure Allan Variance. > Bert Kehren