Ok. I'll leave the xtal's alone. move on to the PS in the MasterLink and clean it up a little. Then close it up.
Thx - all.... RNMarsh
Thx - all.... RNMarsh
State of the are for close in phase noise is the Oscilloquartz BVA http://www.oscilloquartz.com/files/1363164953-Br_ OCXO 8607.pdf . Don't rush to place your order. The lead time was 6-12 months and they are reputed to cost in the $10,000 range. They still have higher phase noise at higher frequencies than a Wenzel blue top ($1,500, 8 weeks if you are lucky). The possibility that either would sound better is very small but it would help justify a $100K DAC.
Richard, the simple fix would be to get the critical oscillators for your effort from Mouser or Digikey: the Crystek oscillators are more than good enough and available as individual parts. If the frequency is not a ratio of 22.5692 or 24.576 its not an audio clock. The 3rd clock in the box is likely for the USB interface and not likely to have any influence.
Richard, the simple fix would be to get the critical oscillators for your effort from Mouser or Digikey: the Crystek oscillators are more than good enough and available as individual parts. If the frequency is not a ratio of 22.5692 or 24.576 its not an audio clock. The 3rd clock in the box is likely for the USB interface and not likely to have any influence.
Elektroj, it takes time to make a complete preamplifier. Often, a small change gives a new rev. Even this rev. is NOT the final rev., or exactly what we build today. PMA, for example, found a problem or two that we had to fix, AFTER the unit was released.
John,
Is there a particular reason why you would use MOSFET follower for the output, instead of JFETs ?
And why such high values for the source resistors (R13, r14) and output resistors (R64, R67) ?
Thanks,
Patrick
Currently, the BVAs are pure unobtainium, even for us at work, and we have bought a
substantial number of them in the past. AFAIK they have sold the farm to Microsemi.
Yes, the Crysteks are quite good, especially if one considers price, size and dissipation.
For my home lab, I have bought one of those Lucent GPS disciplined sources from ebay;
they have 2 double ovens for redundancy and one GPS receiver. The price oscillates
between $150 and $200. At the moment, we are in a low price period.
The oscillators are at 5 MHz since that is a sweet spot; I have done a doubler/distributor.
< http://www.hoffmann-hochfrequenz.de/downloads/DoubDist.pdf >
Sorry, no kits from my side.
regards, Gerhard
(and no, I won't comment on using that stuff for audio.)
Yes, it doesn’t. (*)
I read that you abandoned the idea, this is the good news.
Top notch modern Cesium frequency standards offer at their 10MHz output SSB phase noise worse than most of the clocks you showed on your post #68534
Exctract from Microsemi 5071A specs
SSB Phase Noise 10 MHz :
1Hz - 100dBc
10 Hz - 130dBc
100Hz - 145dBc
1000Hz - 150dBc
10000Hz - 154dBc
100000Hz - 154dBc
Extract from an older Datum FTS 4040A specs
SSB Phase Noise 10 MHz :
1Hz - 99dBc
10 Hz - 130dBc
100Hz - 140dBc
1000Hz - 150dBc
10000Hz - 150dBc
100000Hz - 150dBc
George
(*). You were interested on a used one. HP6061 is the (only?) one ending on e-bay. I was confident though that you would have focused on the important issues.
More than a decade ago, during the investigation phase of purchasing a Caesium clock for disseminating time in a cal lab, tight budget turned us to Rubidium clock. In both cases phase noise was questioned (it would be very convenient for us if we could double the utilization of this unit as a local reference standard for frequency calibrations. We decided that we shouldn't).
But Richard may ask the seller for the phase noise of this Rubidium clock generator
10 000M Ultra Precision Low Noise RB Word Rubidium Atomic Clock Generator HiFi | eBay
and compare to some of these
High Reliability Ruggedized Oscillators | Time & Frequency References | Timing & Synchronization Systems | Products
That was the clear message in jxc post!
See Fig. 35, Fig. 36
Introduction to Quartz Frequency Standards - Oscillator Comparison and Selection
and these
http://www.endruntechnologies.com/pdf/Osc-Guide.pdf
GPS-Derived 1/5/10MHz Low-Phase-Noise Outputs
Ohm's Law, Microscopic View
I hope we will not turn back to April 2014 (all the then participants are still active and kicking, ready for a new round 😀 )
Respect !
George
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George,
As far as I am concerned my issues from last April were settled with this cite from you.
http://www.physik.uni-augsburg.de/~schwab/paps/habil.pdf
However as I recall on April 1st the subject did turn to bruuble brees or some such.
I suspect that is a fine date to do the annual update on that issue.
ES
As far as I am concerned my issues from last April were settled with this cite from you.
http://www.physik.uni-augsburg.de/~schwab/paps/habil.pdf
However as I recall on April 1st the subject did turn to bruuble brees or some such.
I suspect that is a fine date to do the annual update on that issue.
ES
I haven't seen jn for a while so I pass.🙂
I always thought charge was a property not a thing that stands by itself. I think your link will do for the wires we solder down on our circuits.
What do you think q is? Charge without a carrier is an eccentric concept.
That is the top and bottom plates of a charged capacitor.
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Thanks too, George, and to ES for bringing up this paper on the properties that I have been trying to get a deeper understanding of for the last 20 years.
For the rest of you, not so obvious, is it?
For the rest of you, not so obvious, is it?
why? are you now designing liquid He cooled MC preamps?
if you even skim the paper you will find an equation with abs temperature K^-3 dependency for an effect that is ~1-2% at 610 mK
what's 2%*500^-3 (hint: I had to change my 10 digit display calculator to engineering exponential mode)
if you even skim the paper you will find an equation with abs temperature K^-3 dependency for an effect that is ~1-2% at 610 mK
what's 2%*500^-3 (hint: I had to change my 10 digit display calculator to engineering exponential mode)
Hate to veer away from millikelvins, but has anyone read and digested this paper from 14 years ago? IEEE Xplore Abstract - Comparative low frequency noise analysis of bipolar and MOS transistors using an advanced complement...
From just the abstract it seems the conclusions are rather sweeping and invoke skepticism for me at least.
From just the abstract it seems the conclusions are rather sweeping and invoke skepticism for me at least.
You really think that charging a capacitor is not doing work on the charge carriers and storing energy in the field? Charge and electrons are used interchangeably at times, sloppy sometimes maybe.
Do you really think Fairies move charge around as you stated before?
Do you really think that Santa Claus gave you all that stuff?
Or do you just manage to mis-read just about everything?
Where do you get the idea that charging a capacitor does not involve work or anyone even hinted that?
It is clear that you confuse charge with electrons. Current is the movement of charge it is not the movement of electrons. You accuse me of being confused about electron drift.
Now George didn't want all this repeating so this will be my last post on this issue. You can have the final word from whatever ethereal plane you are floating by at the moment.
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