be useful.
I did not think it would raise such an issue.
Didier
Sent from my Droid Razr 4G LTE wireless tracker.
-Original Message-
From: saidj...@aol.com
To: time-nuts@febo.com
Sent: Mon, 26 Nov 2012 4:01 PM
Subject: Re: [time-nuts] pulse height
Hi Didier,
yes, if you put a 50 Ohm
Hi Didier,
yes, if you put a 50 Ohm termination at the far end all looks good, but you
are still driving a 91mA DC current through the cable during the high
times, and that will have rippling effects on the driver board by loading the
5V power supply down with a 1Hz period.
And if you for
saidj...@aol.com said:
> Nice page, but your first plot with R1 = 0 ohms and no R2 shows too much
> ringing.
It shows what I expect. I thought it was an example of what happens if you
set things up that way, not how to get the best results.
> With proper impedance matching that setup will giv
...@aol.com
To: time-nuts@febo.com
Sent: Mon, 26 Nov 2012 2:36 PM
Subject: Re: [time-nuts] pulse height
Didier,
Oh, ok that makes sense, but that is a non-standard output, so not sure
that you want to use such an output as a sample case for generic applications.
Alternatively maybe rename the
Didier,
Oh, ok that makes sense, but that is a non-standard output, so not sure
that you want to use such an output as a sample case for generic applications.
Alternatively maybe rename the page to "Trimble CMOS-output Coax Cable
Impedance Matching" to make that clear.
It would be better
of precise time and frequency measurement
Cc: Discussion of precise time and frequency measurement ,
"M. Simon"
Sent: Mon, 26 Nov 2012 10:44 AM
Subject: Re: [time-nuts] pulse height
Didier,
Nice page, but your first plot with R1 = 0 ohms and no R2 shows too much
ringing.
With proper
quot;M. Simon"
> To: "time-nuts@febo.com"
> Sent: Sun, 25 Nov 2012 3:09 PM
> Subject: [time-nuts] pulse height
>
> Depends on which end of the cable you are looking at. At the source end it is
> 2X the cable "length". At the sink end only 1 cable length.
>
2012 3:09 PM
Subject: [time-nuts] pulse height
Depends on which end of the cable you are looking at. At the source end it is
2X the cable "length". At the sink end only 1 cable length.
One to two uS should be more than enough time for all the reflections to die
out from cable lo
Thanks all for the additional comments and suggestions, re the 1pps output
voltage on my Z3805's. I did confirm that my measurement technique gives
reasonable answers with other 1 pps signals. I also was able to observe an LED
dimly flashing when connected to the 1pps output of one of my Z3805
10:03:46 -0800
From: Said Jackson
To: "M. Simon" , Discussion of precise time and
frequency measurement
Cc: "time-nuts@febo.com"
Subject: Re: [time-nuts] pulse height
Message-ID: <67f262eb-8e0b-4ac1-8bc6-56d696664...@aol.com>
Content-Type: text/plain; charset=u
Mark, Simon,
First, I can check the 1PPS on my Z3805A with a small white LED. The pulse time
is long enough to see in dark light conditions, and it verifies that the output
voltage is >2V, and the driver can supply some mA of current. Primitive but
works really well. Don't use a resistor on the
Unless your coax is unusually long it should only look like 50 ohms on the
leading and trailing edges of the pulse. A rough guide is 1nS per foot. So 10
ft of coax will look like 50 ohms for 10 nS. Of course the velocity factor of
the coax will lengthen that time by roughly 50% for most coax yo
12 matches
Mail list logo
