I don’t see any proof or disproof of the quote. Not saying it is true or false, only that I cannot see any evidence of a 5Hz or more drift in your phase noise measurements.
?? RPi PLLs the 54/27MHz clock to several GHz and generates all the required clocks via fractional dividers. The fractional division (SMASH) used for clocking the I2S interface in master mode generates huge jitter, many orders larger than any impact of the original crystal before the multiplying PLL can have.
IF the clocks on the addon board were used for slaving the I2S interface (with an I2C-controlled clock divider to generate bitclock at cost of a few dollars), it would make sense. Not this.
You should know that for an oscillator using SC-Cut crystal without the oven the frequency will drift more than 5Hz, just take a look at the inflection curve of such crystal.
However, when I measure the phase noise I disable the Frequency stability measurement in the Timepod because with the above mentioned DUT the tool shows an alert message indicating that the frequency is drifting more than 5Hz.
This was the case and it was enough obvious.
So one should try before claim.
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I believe you have not clear the difference between phase noise and frequency stability (Allan deviation), short term vs long term stability.
I don't disable the warning, I disable the "Frequency stability" measurement, that's different from phase noise since the Allan Deviation is a separate plot.
If I don't disable the "Frequency stability" measurement the phase noise does not change.
Is this clear?
Then by measurements the phase noise is not affected by the frequency stability. dot.
When someone claims "And I believe the more than 1Hz frequency shift should be shown on the phase noise plot if that change is within the measurement time." we are in the objective field of measurements.
Such claim it's not true. dot.
Subjective listening impressions are another thing of which I have never argued, although I have my subjective opinion.
It looks good but no one knows when i have i2s fifo pi q3 reclocer did have sens.Hi ! To change the clock on the rpi4 board you can refer to this circuit
??? Raspberry Pi 4B ??? ??? OCXO ???? ????-???
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No, it is not clear, and you did not prove or disprove anything, a claim is not a proof. But please don’t bother, and save yourself another rant about my knowledge on the matter.
It is exactly what I have done!
No matter it plays Native DSD or PCM, it is very good, there is no problem at all.
In addition, the software I use is moOde or piCorePlayer
If it is not clear, sorry it's your problem which demonstrates your knowledge on the matter.
We have built and measured the phase noise of the oscillator with and without the oven, so we know the results.
I'm not particularly concerned with proving anything to you. I hope you understand this sooner or later.
Then why are you replying to my messages showing an obvious lack of knowledge? Never mind, I know the answer.
You still did not prove anything. If anybody needs authoritative references regarding the frequency drift effect on the phase noise, I am willing to build a list. Andreas doesn’t need anything, he already has all the answers and a timepod on top.
You still did not prove anything. If anybody needs authoritative references regarding the frequency drift effect on the phase noise, I am willing to build a list. Andreas doesn’t need anything, he already has all the answers and a timepod on top.
You still don't understand, I don't want to prove anything to you.
You can prove this by yourself by looking at the pictures of the posts #7142 and #7144.
If you don't understand the relationship it's your problem, not mine.
You are not an authority on this matter, they have already told you this several times.
Haven't you figured it out yet?
Before going into math and advanced signal processing references, here’s a Rohde infomercial about the difficulties of measuring the close in phase noise in the presence of frequency drift. It’s at the Andreas level, so it should not be difficult for anybody interested to follow.
R&S FSV3000: Measuring phase noise of frequency drifting oscillators - YouTube
R&S FSV3000: Measuring phase noise of frequency drifting oscillators - YouTube
The problem is that it's difficult for you to follow.
Anyway the pink curve is the phase noise plot with the oven (no frequency drift) while the blue plot is the phase noise of the same oscillator without the oven (with frequency drift).
They are practically overlapped.
Now please buy the R&S FSV3000 and try to demonstrate the opposite.
Until you will succeed you are just posting rants without any proof.
As usual.
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If anything, the dilemma is whether to believe Rohde & Schwarz or John Miles / Bruce Griffiths / Microsemi.
However, the dilemma does not exist, since you have posted a link that does not explain anything about the specific case.
Anyway the main problem is that I have published measurements (proof) while, as usual, you are claiming without any proof.
Again please buy the R&S FSV3000 and try to demonstrate the opposite instead of claiming without any evidence.
Sure, since you seem to be yet another expert in the matter, have you computed the theoretical phase noise error @1Hz due to a 5Hz FM fluctuation? It’s a rather trivial calculation that I’m sure you are aware of. If in doubt, I am also sure Andreas would be more than happy to help.