Hi,

On 09/18/2016 12:26 PM, David C. Partridge wrote:

Consider full-wave rectification of 50 Hz, the power consumption load on
the capacitor after the rectifier creates an inverse sawtooth wave of
100 Hz, and sawtooth waveshape have both even and odd harmonics.

While much of this is regulated out in the next step, some of it makes
it though.

Cheers,
Magnus

Even harmonics are caused by asymmetrical nonlinearities, odd harmonics by
symmetrical nonlinearities.

Peter

Am Sonntag, 18. September 2016 schrieb Magnus Danielson :

Thanks, that makes sense.  Is the PN plot much as expected, or is it "could do better"?

Thanks again
Dave
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Magnus Danielson
Sent: 18 September 2016 11:56
To: time-nuts@febo.com
Cc: magnus@rubidium.se
Subject: Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Hi,

On 09/18/2016 12:26 PM, David C. Partridge wrote:

Consider full-wave rectification of 50 Hz, the power consumption load on the capacitor after the rectifier creates an inverse sawtooth wave of
100 Hz, and sawtooth waveshape have both even and odd harmonics.

While much of this is regulated out in the next step, some of it makes it though.

Cheers,
Magnus

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Assuming a nonlinearity, a distortion or partly clipping of only one
halfwave, would result in a massive even harmonic, as the 200Hz in the
example. From this point of view "as expected", but a different distortion
could as well result in any other even harmonic.

Peter

Am Sonntag, 18. September 2016 schrieb David C. Partridge :

The PN should be considerably lower than that even with the noisy output buffer the PN floor should be considerably lower (>40db lower). The OCXO by itself should have somewhat lower PN.
Bruce

On Sunday, 18 September 2016 11:14 PM, David C. Partridge <david.partridge@perdrix.co.uk> wrote:

Thanks, that makes sense.  Is the PN plot much as expected, or is it "could do better"?

Thanks again
Dave
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Magnus Danielson
Sent: 18 September 2016 11:56
To: time-nuts@febo.com
Cc: magnus@rubidium.se
Subject: Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Hi,

On 09/18/2016 12:26 PM, David C. Partridge wrote:

Consider full-wave rectification of 50 Hz, the power consumption load on the capacitor after the rectifier creates an inverse sawtooth wave of
100 Hz, and sawtooth waveshape have both even and odd harmonics.

While much of this is regulated out in the next step, some of it makes it though.

Cheers,
Magnus

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.

Now that's interesting I just re-ran the measurement, and got a quite different result which is attached.  The spurs have GONE.

My only guess right now is that the E4406A power supply is getting quieter as it has been on for longer (I've only had it powered for short periods before now).

Dave

-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Magnus Danielson
Sent: 18 September 2016 11:56
To: time-nuts@febo.com
Cc: magnus@rubidium.se
Subject: Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Hi,

On 09/18/2016 12:26 PM, David C. Partridge wrote:

Consider full-wave rectification of 50 Hz, the power consumption load on the capacitor after the rectifier creates an inverse sawtooth wave of
100 Hz, and sawtooth waveshape have both even and odd harmonics.

While much of this is regulated out in the next step, some of it makes it though.

Cheers,
Magnus

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

The phase-noise still looks fairly high. How do you measure this?

Cheers,
Magnus

On 09/18/2016 01:27 PM, David C. Partridge wrote:

The signal level is also very low.
Brue

On Sunday, 18 September 2016 11:47 PM, Magnus Danielson <magnus@rubidium.dyndns.org> wrote:

The phase-noise still looks fairly high. How do you measure this?

Cheers,
Magnus

On 09/18/2016 01:27 PM, David C. Partridge wrote:

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Indeed, now I see it. As we expect around +10 dBm, the noise-floor might
be raised by about 20 dB.

I was more considering what is the reference noise here, is there a
single oscillator as reference? Can a quieter reference oscillator be
used? Can a cross-correlation setup be done?

Cheers,
Magnus

On 09/18/2016 01:52 PM, Bruce Griffiths wrote: