> Dave B. (G0WBX)
>
> PS: I do like the idea of setting up a camera to take a photo of the
> 'scope every hour or so! Not practical for many I guess, but it
> illustrates the point well. But the aliasing opportunity I think would
> be perhaps too great, in essence being a sampled data system by
ink would
be perhaps too great, in essence being a sampled data system by then.
Also, one then needs an accurate 1 hour timer! And so it goes on ;-)
On 28/09/18 17:00, time-nuts-requ...@lists.febo.c
In addition to nonlinear issues with output amplifiers, filters have
poor performance when improperly terminated. This can lead to harmonic
distortion and that can be a problem. You want the duty cycle to be
exactly 50%. See:https://tf.boulder.nist.gov/general/pdf/1437.pdf
--
Bill Byrom N5BB
To: Discussion of precise time and frequency measurement
Sent: Thursday, September 27, 2018 11:19 AM
Subject: Re: [time-nuts] A silly question ...
> "I think", that if for example, it takes 1 second to drift one cycle,
> that works out at 0.1 ppm. If it takes 2 second
Hi,
There is one other issue that can bite you if you fail to properly
terminate the output of a source:
Depending on the source's design, an essentially unloaded output
can have a substantially higher voltage swing than expected (by
2X if the source impedance is actually 50 ohms), possibly
On Thu, Sep 27, 2018, at 11:55 AM, Dave B via time-nuts wrote:
> Triggering a dual beam 'scope (Tek 465) from the TB on Ch1, and having> the
> output of the OCXO on Ch2, the resulting display on Ch2 of course> drifts in
> relation to the static waveform on Ch1. (Both nice
> sinusoids.)
The Tek
-Original Message-
From: time-nuts On Behalf Of Tom Van Baak
Sent: Thursday, September 27, 2018 2:18 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] A silly question ...
> "I think", that if for example, it takes 1 second to dr
> "I think", that if for example, it takes 1 second to drift one cycle,
> that works out at 0.1 ppm. If it takes 2 seconds, it's 0.05 ppm, if it
> takes 5 seconds, it's 0.02 ppm etc. Is that correct?
Yes. At 10 MHz one full cycle is 100 ns. So if the cycles are drifting by 100
ns per second
Even with a DSO, if you sync to the Thunderbolt output, you can watch the free
running osc drift relative to the Thunderbolt.
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Correct.
David N1HAC
On 9/27/18 12:55 PM, Dave B via time-nuts wrote:
> ... Because I'm sure I should be able to figure this out for myself!
>
> I have (as many of you do also) one of the venerable Trimble Thunderbolt
> devices. No problem with that. All works fine, and is run 24/7, UPS
>
... Because I'm sure I should be able to figure this out for myself!
I have (as many of you do also) one of the venerable Trimble Thunderbolt
devices. No problem with that. All works fine, and is run 24/7, UPS
backup power and all...
I also have (again, as many of you do...) a free running
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