[TangerineSDR] Attempt #2 to send charts describing the ADEV and Phase noise

[Scotty Cowling]

ZIP file came across fine! But I still had to approve the over-size.

I will raise the limit to 2MB, will that be enough? Or should I go to 10MB?

10MB is the maximum that my ISP will allow in an e-mail anyway, so 
greater than that won't be useful.

73,
Scotty WA2DFI

On 2019-04-24 12:17, Tom McDermott via TangerineSDR wrote:
>
> Apparently email with the in-line figures does not get processed 
> correctly.
> This is an attempt to handle them as an attachment.  The zip 
> attachment has
> three figures. 223 Kbytes.
>
> I measured the Allan Deviation of the Silicon Labs de-jitterizer / 
> synthesizer on the Silicon Labs
> evaluation board.  This part is a candidate for generating the ADC 
> clock and FPGA DDC NCO
> from a GPS receiver.
>
> Tests:
>
> 1. Allan Deviation vs. de-jitterizer bandwidth. The ADEV degrades a 
> lot for loop bandwidths
> less than 100 Hertz (as the datasheet cautions).
>
> 2. Allan Deviation vs. Synthesizer output frequency.
>
> For most frequencies, the curves lay on the same line at 10.0 MHz 
> output (see chart attached).
> I was able to find one frequency especially picked to give the 
> synthesizer a tough time, and the
> Allan Deviation of that is substantially worse (see chart).  That 
> frequency is 48.0 M * 31/149,
> or 9.986571812 MHz. rounded to the nearest milliHertz.
>
> My test setup:  Rubidium oscillator at 10.00000 MHz (undisciplined) 
> feeding both the synthesizer
> and the reference input to a TICC. TICC is thus measuring the 
> synthesizer output vs. the synthesizer input.
>
> 3. John Ackermann N8UR has measured the phase noise vs. loop 
> bandwidth, and there are some tradeoffs.
> John will have to describe his test setup, I believe it was done at 
> 144.195 MHz.
>
> -- Tom, N5EG
>
> Attachments:
>
> ADEV vs. Loop BW. The magenta line is 100 Hz loop bandwidth (default 
> value). All measurements at 10.00000000 MHz output.
> ADEV vs. 10.00000000 and 9.986571812 MHz output
> (from John Ackermann) Phase noise vs. loop BW.
>
>
>

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