For the specific application of driving an FPGA clock pin (that has an
enormous input bandwidth) many things can go wrong.
All fine about the advantages and disadvantages of
the gate with resistor feedback, all I can say is that over here I it
was not the best solution
we found over many FPGA
Hi
Did you try running it at 3.3V and going into an LVDS input on the FPGA?
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of ct1dmk
Sent: Monday, July 23, 2012 7:26 AM
To: Discussion of precise time and frequency measurement
Hi Bob,
No, never tried but it looks a good idea.
Our boards all have 5v so there was never any pressure...
... for a 0.5v in the tail resistor to vcc and 0.7v of vbe
I could easily allow collectors to swing some 300mv around 1.2V...
a couple of resistors more than my single ended solution...
Hi Guys,
I have a couple of Trimble T Lassen 2 boards I bought at a Hamfest -
the guy told me they were left over from a contract he had and were
brand new. He had a load and i bought a couple for use as a precision
1 PPS output for radio stuff. They were packed in static protection.
When I apply
Do not be too quick to toss out the antennas. Some receivers need the
antenna power to be connected to a pin on the receiver connector that is
then internally routed to the antenna.
John WA4WDL
--
From: Stephen Farthing squir...@gmail.com
Sent:
...And don't forget that the PPS pulse is very narrow so you have to use a
'scope with memory, a digital 'scope or turn the brightness at max.
On Mon, Jul 23, 2012 at 6:31 PM, jmfranke jmfra...@cox.net wrote:
Do not be too quick to toss out the antennas. Some receivers need the
antenna power
The pulse from my T-Bolt is on the order of 1uS wide. I captured it on the
digital scope for posterity and future reference.
http://www.fastbobs.com/pictures/1pps.jpg
Bob
On Mon, Jul 23, 2012 at 12:58 PM, Chris Albertson albertson.ch...@gmail.com
wrote:
I wass fooled by this too. My analog
Wow, that is indeed narrow. Only 1us out of a 1 second rep rate. That is one
millionth of the rep rate. No wonder analog scopes will not catch it. I'll
have to try it some time. Regards - Mike
Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
Guys,
Thanks for all the advice. I'll let you know how it goes...
Steve
On 23 July 2012 18:06, time-nuts-requ...@febo.com wrote:
Send time-nuts mailing list submissions to
time-nuts@febo.com
To subscribe or unsubscribe via the World Wide Web, visit
squir...@gmail.com said:
While i am on, can anyone suggest a reasonably priced unit that has a 1pps
output, NMEA and a built in antenna. Because I want to use this with an 8
bit embedded system I am probably not going to be able to hack one of the
many cheap USB dongle GPS's.
Garmin GPS
And here it goes again for about the umpteenth time, how to detect the
presents of a short low rep rate pulse.
This can be done with ANY analog scope by using the normal trigger mode
and setting the trigger correctly.
An analog scope can detect the presents of any short pulse no matter how low
Hi
The nice thing about going into the LVDS inputs is that you are differential
right at the FPGA. Often that's where a *lot* of junk is running around.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of ct1dmk
Sent: Monday, July
My old '465 will trigger on the 1pps, but it's far easier to see the
trigger LED flash than finesse the brightness/sweep to make it visible -
something possible only on a 'scope with a decently bright tube.
Another cheap/easy trick to detect the 1pps pulse is simply to listen
to it with an
Set the scope sweep speed to 10 milliseconds per division and then even a
dull scope is easy to see. You are looking for trigger events from the 1PPS,
not the 1PPS itself.
John WA4WDL
--
From: C. Turner tur...@ussc.com
Sent: Monday, July 23,
That works when there is a trigger LED,
OR Just need to slow down the sweep rate to say 10ms / div or slower and
then there will be a nice clear, easy to see, can't miss, white line, across
ANY scope with each pulse when the scope is triggered by a short low rep
input pulse.
Is there a commonly accepted shorthand for a frequency, say 10MHz, generated at
the maximum accuracy of the lab generating it?
ie instead of writing 10.5MHz?
Pete
G4GJL
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
Yes, 5E-10, valid for every frequency.
On Mon, Jul 23, 2012 at 10:50 PM, g4...@btopenworld.com wrote:
Is there a commonly accepted shorthand for a frequency, say 10MHz,
generated at the maximum accuracy of the lab generating it?
ie instead of writing 10.5MHz?
Pete
G4GJL
I'm having a problem getting Lady Heather up and running with Windows 7.I
attempted to change the com port to 3 per KE5FX's web site using the command
C:\Program Files\Heather\heather.exe/2 and I get an error message that tells
me that the command is not valid. What gives?
Bud
WØLCP
Hi Bud,
the /2 should be inside the quotes as you show it. Of course the quotes are
not used in the windows environment. That should be /3 if you are wanting to
go to port 3. So your command line, used in the ICON or link, should read:
C:\Program Files\Heather\heather.exe /3
Hopefully that
I think you need a space before the /2.
C:\Program Files\Heather\heather.exe /2
But I could be wrong.
Tom
- Original Message -
From: Bud Patten bud.pat...@frontiernet.net
To: time-nuts@febo.com
Sent: Monday, July 23, 2012 6:00 PM
Subject: [time-nuts] Heather Problem..
I'm having
Hi Pete,
Yes, there are several ways to represent frequencies:
1) Absolute units of Hz. For example 60 Hz, or 32.768 kHz, or 3.579545 MHz, or
9.192631770 GHz. Note some modern texts use s⁻¹ (1/s or s-1) instead of Hz or
Hertz. Or, you can always show your age and use cps (cycles per second).
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of WB6BNQ
Sent: Monday, July 23, 2012 3:07 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Heather Problem..
Hi Bud,
the /2 should be inside
Hi John,
I stand corrected. I fooled myself because I usually load my programs in a
different directory where no spaces exists. thus I was lulled into not learning
something before. Thanks for the refresher.
BillWB6BNQ
John Miles wrote:
-Original Message-
From:
Www. KO4BB.com/Test_Equipment/Thunderbolt/PulseStretching/
It does not have to be complicated
Didier KO4BB
Mike Feher mfe...@eozinc.com wrote:
Wow, that is indeed narrow. Only 1us out of a 1 second rep rate. That
is one
millionth of the rep rate. No wonder analog scopes will not catch it.
Now that I have my new [30 year old] HP 3586 making measurements
over the GPIB bus I have a few questions.
Setting AVErage makes measurements take about three seconds.
Is there a way to control the number of samples averaged?
How difficult is it to open up the 3586 to replace the input
On 7/23/12 3:23 PM, Tom Van Baak wrote:
Hi Pete,
Yes, there are several ways to represent frequencies:
1) Absolute units of Hz. For example 60 Hz, or 32.768 kHz, or
3.579545 MHz, or 9.192631770 GHz. Note some modern texts use s⁻¹ (1/s
or s-1) instead of Hz or Hertz. Or, you can always show
26 matches
Mail list logo
