[time-nuts] Re: Seems like the new version PN2060C is available for sale US$680

[Bob Camp]

Hi

One way or the other, the spurs are from an internal source in the device. If you do the math, you can’t get “heterodyne” spurs directly from the inputs when both of them are from the same source. As they mention in their little footnote, there may be issues with the internal clocking approach. 

Simply blanking them is not a good idea. There are enough of them you could easily blank out something else. Based on their very limited comment, I don’t believe they are headed in that direction. 

Any design like this is full of grubby details that need to be addressed. There is always going to be a lot of testing, finding things, working out what they are, and coming up with a fix. We tend to *assume* that will be a software fix and there’s just an update. Whatever we bought “early on” just gets new code and it works fine. With low level signal processing (which this is), that’s not always the case. Sometimes it’s the hardware than needs a fix …..

Bob

> On Oct 6, 2023, at 4:29 AM, drew wollin via time-nuts <time-nuts at lists.febo.com> wrote:
> 
> Hi
> 
> The spurs are an issue, but their cause seems a mystery to me. However, it occurred to me today that they may be odd harmonics (or "sub-harmonics" for overtone crystals over 20 MHz).
> 
> This seems a plausible explanation as there shouldn't be such high phase noise that far from the DUT frequency.
> 
> The spurs change with frequency as per the YouTube video.
> 
> I have emailed the PN2060C maker to see what he thinks.
> 
> The commercial analysers may be aware of the harmonics as spurs and have scripts to remove them.
> 
> Any thoughts?
> 
> Regards Drew VK4ZXI
> 
> https://www.youtube.com/watch?v=wKDBUkGKul8&ab_channel=heisenberg
> 
> 
> Subject: [time-nuts] Re: Seems like the new version PN2060C is
>        available for sale US$680
> To: Discussion of precise time and frequency measurement
>        <time-nuts at lists.febo.com>
> Message-ID: <618AFACD-623D-487B-916B-60DA01A1D3DE at n1k.org>
> Content-Type: text/plain;       charset=utf-8
> 
> Hi
> 
> Looking at their plot of the 10 MHz OCXO into both inputs:
> 
> There are some pretty significant spurs on that plot. From the notes below it, they seem to still be digging into the source of those spurs and ways to reduce / eliminate them. I think there still is a bit more work to be done. They imply the fix could be hardware rather than software. If so, I’d wait for the next version ….
> 
> Bob
> 
>> On Oct 3, 2023, at 2:29 AM, drew wollin via time-nuts <time-nuts at lists.febo.com> wrote:
>> 
>> Hi All
>> 
>> According to the updated PN2060c webpage, the new version is now available for sale at US$680.
>> 
>> It has an improved noise floor and less trouble with spikes. The device is a significant rework of the original PN2060A design.
>> 
>> I have the PN2060A and am very impressed by it. The new version looks better.
>> 
>> Regards Drew VK4ZXI
>> 
>> 
>> https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fqsl.net%2Fbg6khc%2Fpn2060c_phase_noise_analyzer.htm&data=05%7C01%7C%7C20523c9c8c9c4c8af7de08dbc4abd78b%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638320014592530175%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=zsmd4nUk8qfEsdfHvcwMuxxw1neqLh5lJ%2F%2FWY5uh%2BM8%3D&reserved=0<https://qsl.net/bg6khc/pn2060c_phase_noise_analyzer.htm>
>> ___
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