Tom Knox wrote:
Dual oscillators in Cross Correlated
measurements will also produce a 3dB theoretical reduction in a Phase
Noise measurement system.
Since when?
Its way better than that.
I routinely achieve a PN floor below -170dBc/Hz (I don't have an OCXO
with a phase noise floor below ~
and not having a -175dBc/Hz reference, how you can tell that your dual
-150dBc/Hz performs like a -170dBc/Hz?
Moreover: what is the physical principle that can explain this? Injection
locking? Average in the power summer? Taking hundreds or thousands
oscillators it seems possible to reach
Azelio Boriani wrote:
and not having a -175dBc/Hz reference, how you can tell that your dual
-150dBc/Hz performs like a -170dBc/Hz?
You can't.
Moreover: what is the physical principle that can explain this? Injection
locking?
Not injection locking just the magic of cross corrrelation.
Am 30.12.2012 06:18, schrieb Hal Murray:
,The Tuxedo Park book reported that Loomis had 3 Shortt clocks setup
in a basement lab carved out of bedrock. They would get locked unless
they were swinging 60 degrees to each other.
Rohde Co have the math for the phase noise of arbitrary many
Bruce,
The Tsc5125A and miles Timepod show a phase noise floor 3dB above the noise
floor of the two oscillators (if two are used with identical noise floors).
Your oscillators are better than you think, or your equipment is not calibrated.
Btw: that result IS what you want, why would you want
maybe if it ever gets gebraucht enough . . . :-)
happy new year to all
Don
Gerhard Hoffmann
Am 30.12.2012 06:18, schrieb Hal Murray:
,The Tuxedo Park book reported that Loomis had 3 Shortt clocks setup
in a basement lab carved out of bedrock. They would get locked unless
they were swinging 60
and not having a -175dBc/Hz reference, how you can tell that your dual
-150dBc/Hz performs like a -170dBc/Hz?
Moreover: what is the physical principle that can explain this? Injection
locking? Average in the power summer? Taking hundreds or thousands
oscillators it seems possible to reach
Bruce,
The Tsc5125A and miles Timepod show a phase noise floor 3dB above the
noise floor of the two oscillators (if two are used with identical noise
floors).
Bruce is actually talking about a semi-undocumented trick with the TimePod
that allows it to act like an E5052 or TSC 5120A-01 with
John,
If the math works out, then I guess it must work.. If one has the time to wait..
Bye,
Said
Sent From iPhone
On Dec 30, 2012, at 16:23, John Miles jmi...@pop.net wrote:
Bruce,
The Tsc5125A and miles Timepod show a phase noise floor 3dB above the
noise floor of the two oscillators
Said,
On 31/12/12 03:36, Said Jackson wrote:
John,
If the math works out, then I guess it must work.. If one has the time to wait..
It does work. Tried it with a handfull of BVAs and the graphs make sense.
Want quieter oscillators now.. :)
Cheers,
Magnus
Hi,
I've been playing around with 2 HP 5065A standards to see if averaging
them will give better stability.
Corby,
So that's an interesting experiment. I think the key is keeping them in tight
phase so that what you gain in combined performance is still better than what
you lose with the
Tom,
On 29/12/12 18:11, Tom Van Baak wrote:
Corby,
So that's an interesting experiment. I think the key is keeping them
in tight phase so that what you gain in combined performance is still
better than what you lose with the additional mixing electronics.
If you just mixup, then you do not
1) This was a topic some years back -- for internal use, hp tightly
combined multiple 10811 oscillators so that the net phase noise or
short-term performance was significantly better than any one of the
constituent oscillators.
Care to share a reference on that? It would be
-boun...@febo.com] On Behalf Of Tom Van Baak
Sent: Saturday, December 29, 2012 20:17
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] ensemble oscillators for better stability
1) This was a topic some years back -- for internal use, hp tightly
combined
another 3dB etc. Dual oscillators in Cross Correlated
measurements will also produce a 3dB theoretical reduction in a Phase
Noise measurement system.
Thomas Knox
Date: Sat, 29 Dec 2012 23:33:52 +0100
From: mag...@rubidium.dyndns.org
To: time-nuts@febo.com
Subject: Re: [time-nuts] ensemble
i...@blackmountainforge.com said:
I know that this is not germane but I keep thinking of this video:
http://www.youtube.com/watch?v=kqFc4wriBvE
32 mechanical metronomes on a moveable floor. They all sync up in a bit more
than two minutes.
Neat. Thanks.
The Tuxedo Park book reported that
Hi,
I've been playing around with 2 HP 5065A standards to see if averaging
them will give better stability.
The results so far are:
1 sec10 sec100 sec
unitA1.28-123.83-13 1.33-13
unitB9.31-133.44-13 1.18-13
combined
Hi Corby -- I've often thought of the idea of mixing two 5 MHz sources in a DBM
and using the resulting 10 MHz, so I'm really curious to see how this works
out. Seems like injection locking is the most likely problem you'd have to
deal with.
Let us know how this goes!
John
On Dec 28, 2012,
...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Ackermann N8UR
Sent: Friday, December 28, 2012 3:20 PM
To: Discussion of precise time and frequency measurement
Cc: time-nuts@febo.com
Subject: Re: [time-nuts] ensemble oscillators for better stability
Hi Corby -- I've often
and frequency measurement
Cc: time-nuts@febo.com
Subject: Re: [time-nuts] ensemble oscillators for better stability
Hi Corby -- I've often thought of the idea of mixing two 5 MHz sources in
a DBM
and using the resulting 10 MHz, so I'm really curious to see how this
works out.
Seems like
On Fri, 28 Dec 2012 15:19:43 -0500
John Ackermann N8UR j...@febo.com wrote:
Hi Corby -- I've often thought of the idea of mixing two 5 MHz
sources in a DBM and using the resulting 10 MHz, so I'm really curious
to see how this works out. Seems like injection locking is the most
likely
John,
Injection locking won't be a problem with the isolation I have in the
setup.
Azelio,
The 1 second results are referenced to a cherry picked FTS 1200 quartz
which is better than 3X10-13th at 1 second.
The 10 and 100 second results are referenced to an EFOS2 Active Hydrogen
maser.
After
Hi Corby,
On 28/12/12 20:12, cdel...@juno.com wrote:
Hi,
I've been playing around with 2 HP 5065A standards to see if averaging
them will give better stability.
The results so far are:
1 sec10 sec100 sec
unitA1.28-123.83-13 1.33-13
unitB
My first idea would be to mutually lock the oscillators. You can even do
weighted locking without much difficulty. You toss the oscillators into a
mixer, use it as a phase detector, do the usual PI control and then steer
both oscillators the same EFC but with opposite sign. One can add a
Hi
For three:
Compare A to B via a mixer and put in a PID loop.
Compare A to C via a mixer and put in a PID loop.
Sum A with B with C via a three input analog adder.
For thirteen:
A to B via PID
A to C via PID
A to D via PID ….
… sum A with B with C with …. M via a 13 input analog adder.
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