Hi
If you do a power sweep on a crystal resonance, it’s a very predictable sort of
thing.
Essentially you “chase” the resonance up (or down) in frequency with the sweep.
At some
point, it “snaps” and drops back to the low power line. I suspect that what is
being observed
is the “snap” as the
That is a most interesting suggestion.
Suppose the filter crystal was pulled to the DUT frequency, and due
to the inertia of its very high Q, was able to show you the phase noise
variations of the DUT better than one might expect?
-Chuck Harris
Bob Camp wrote:
>.One thing you may be seeing
gt; To: Discussion of precise time and frequency measurement
> Reply To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] notch filter for close in phase noise measurement
>
>
> Hi
>
> One of the limitations of the return loss bridge approach ca
Message
From: Bob Camp
Sent: Sunday, October 2, 2016 22:09
To: Discussion of precise time and frequency measurement
Reply To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] notch filter for close in phase noise measurement
Hi
One of the limitations of the return loss
I gave up here. If the topology is of no use, this is it. For me it was
>> funy to _discover_ that simple topology doing a notch.
>>> Best,
>>> Adrian
>>>
>>> Sent from my BlackBerry 10 smartphone on the Orange network.
>>> Original Message
&
Sent from my BlackBerry 10 smartphone on the Orange network.
Original Message
From: Chuck Harris
Sent: Sunday, October 2, 2016 19:40
To: Discussion of precise time and frequency measurement
Reply To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] notch filter
Adrian,
Simple is nice, but if we cannot talk about the limitations
that come about because of the simplicity, without causing
offense, how can we ever know if simple is good enough?
-Chuck Harris
Adrian Rus wrote:
> Rick,
> Why hunt goose with the cannon? The post is about a simple(r) crystal
minuses of notch
> filer measurement methode, remain.
> >> Sooner (or later) I shall share with you (after the real life
> validation) an (again, very simple) interderometric methode.
> >> Adrian
> >>
> >> Sent from my BlackBerry 10 smartphone
ment
> Reply To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] notch filter for close in phase noise measurement
>
>
> Hi
>
> Ok, the next issue with the notch filter technique is the termination of the
> oscillator
> it’s self.
of precise time and frequency measurement
Subject: Re: [time-nuts] notch filter for close in phase noise measurement
Hi
Ok, the next issue with the notch filter technique is the termination of the
oscillator
it’s self. The notch may (or more likely not) provide a proper 50 ohm load
) Karlquist
Sent: Sunday, October 2, 2016 18:35
To: Discussion of precise time and frequency measurement
Reply To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] notch filter for close in phase noise measurement
On 10/2/2016 12:56 AM, Adrian Rus wrote:
> Hello l
r 2, 2016 17:54
> To: Discussion of precise time and frequency measurement
> Reply To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] notch filter for close in phase noise measurement
>
>
> Hi
>
> The notch is (say) 60 db deep at the carrie
On 10/2/2016 12:56 AM, Adrian Rus wrote:
Hello list,
For those of you interested in phase noise measurement without using
fancy/dedicated gear,
There is no free lunch here. The crystal has its own
intrinsic flicker of frequency noise. You cannot
measure below this noise floor. The
time and frequency measurement
Subject: Re: [time-nuts] notch filter for close in phase noise measurement
Hi
The notch is (say) 60 db deep at the carrier frequency. At 100 Hz off the
carrier frequency,
it still has some depth. It might be 50 db deep, it could be 10 db deep. A lot
depends
measurement
> Reply To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] notch filter for close in phase noise measurement
>
>
> Hi
>
> Getting close to carrier with a notch filter involves a bit of calibration of
> the notch. It’s
.
Original Message
From: Bob Camp
Sent: Sunday, October 2, 2016 17:06
To: Discussion of precise time and frequency measurement
Reply To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] notch filter for close in phase noise measurement
Hi
Getting close to carrier
Hi
Getting close to carrier with a notch filter involves a bit of calibration of
the notch. It’s not
imposible to do, but it is a needed step. The generator you use to do the
measurement has
to be pretty clean to get adequate data at low offsets.
Bob
> On Oct 2, 2016, at 3:56 AM, Adrian Rus
Hello list,
For those of you interested in phase noise measurement without using
fancy/dedicated gear, here you are the way I have got. Disclaimer: as far as I
am concerned, all phase noise measurements use a technique to get rid of
carrier: quadrature mixing, interferometric [more on that,
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