Remember * * * these DAs are designed be unity gain and to
handle approximately 1 volt p-p so be carefull of clipping if you
drive much more than that level or alternatively, pad down the input
to a 1 volt level.
Also, video DAs are designed to drive 75 ohms (the video world's
standard
If it is a really good Rb standard, consider adjusting the
standard yourself by measuring the phase over several
days once the standard has warmed up and settled down.
A GPIB counter with phase measurement is useful for this.
--
Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com
Hi Bjorn
Is yours also the cut down 2.084MHz version, or do you have a proper
8821B with a more useful GPSDO frequency and all the outputs fitted?
I think this one was originally used in a trunked radio system.
I've just checked and the fitted VP Oncore is the B8121Z116, so perhaps
the
I think that it is the time for you to look at the TimePod: the TimePod can
help you with Allan Deviation and phase noise measurement, the next step
after clocks is measuring equipment and the TimePod is a sort of all-in-one
for time-nuts, its place is right after the bench yellow multimeter.
On
In your opinion, if I build a 7404 ZCD and a hard limiter one, can I see
the jitter difference on a simple 'scope (Tek TDS220 or TDS3012) or do I
need the Wavecrest SIA3000?
On Wed, Aug 22, 2012 at 1:37 AM, Bob Camp li...@rtty.us wrote:
Hi
Since the Collins approach tunes the system for a
Edgardo,
Congrats on getting the 5065A up and operational. Make sure the A11 Board
(Temperature Controller) is all OK. Failure there can destroy the A12 RVFR
Assembly. There is a lot of 'expertise' on the list for this unit.
What is the serial number of your unit and what is the part number
Do you mean with a 7404 hex inverter? I actually did something like
this recently while adding a 75ns pre-trigger pulse to an existing
fast rise pulse generator.
The pre-trigger pulse ended up having significant pattern dependant
jitter caused by the adjacent TTL divider chain modulating the
According to
http://cp.literature.agilent.com/litweb/pdf/5989-8794EN.pdf
the real time sampling scope (like the TDS220 or TDS3012) can measure cycle
to cycle jitter directly, whereas the equivalent time sampling has only one
sample each trigger and a little delay on the sampling point for the
Hi Nigel,
Yes, I have the same version. We might have got it from the same UK epay
source. The GPS did not work reliably, and I did start testing that module
outside the Trak unit, and also tried VP(8chan) receivers that I had. Did
not really conclude why the GPS did not behave properly. I was,
http://www.jan-mayen.no/
press news
Look for 21. august.
The last picture is particularly interesting:
http://www.jan-mayen.no/nyhet/2012/08_august/C-%20mast/C-mast%208b.JPG
Here you can see both the top-hat which forms the capacitance, they
guy-wires which hold the mast in place and
On 08/22/2012 01:22 AM, Edgardo Molina wrote:
b. Is it possible to build a GPSDRb? I would like to know if it is reasonable
to pursue the goal to discipline the 5065a with a TB which I also got recently.
Some Rbs have a C-field input that can technically be used to
discipline it, but this is
Hi
The gray case is the original design case. For what ever reason, it turned
out to be a problem for at least one intended application. The final design
case flipped the board over to take care of what ever problem the original
orientation created.
Bob
-Original Message-
From:
Hi
It depends very much on just how low a frequency sine wave you put into the
limiter. If you run low enough, then indeed you will be able to see the
difference. If the scope can display 1 ns jitter, then a 1 Hz sine wave is
likely to be low enough.
Bob
-Original Message-
From:
Hi
The problem you run into with this approach is that it is relatively high
jitter. You output jumps by what ever your microcontroller step time step
size is every so often. Since that's going to be 10's or possibly 100's of
ns, it's a major hit.
Bob
-Original Message-
From:
Hello Everyone,
Thanks to Azelio, Bob and David for their comments. Special thanks to Magnus
for clarifying the intent of this paper. I think I begin to understand the 'k'
term.
When I look at jitter, I actually look at residual phase noise using the E5500
phase noise measurement system. One
On Wed, Aug 22, 2012 at 7:47 AM, Michael Tharp g...@partiallystapled.comwrote:
The design I'm thinking of is to have a separate microcontroller clocked
by the Rb that will generate a third pulse-per-second
It is very hard to write a divers in software. You have to use assembly
language and
Thought you guys might like to read this and maybe send them some more reports:
-Original Message-
From: Brad Dye [
mailto:b...@braddye.com
Sent: Tuesday, August 21, 2012 2:36 PM
To: inquiry
Subject: WWV Voice Time Announcements
Have you posted any official news about WWV
Exactly. Every GPSRb works by adjusting the C-field: sort of let me (the
algorithm/GPS pair) calibrate your Rb for the long term (aging) variation
that every Rb has. The Rb is not good in the long term (10 seconds),
not as good as a working and receiving GPS receiver. The Rb (as a whole)
*is*
I was not measuring cycle to cycle jitter but the input to output
jitter of a TTL gate itself when used as part of a delay circuit. The
input circuit and input waveform to the gate are very similar to what
would be expected in a sine wave zero crossing detector.
Using a 7S11/7T11 in sequential
Brad,
Could you please elaborate on what exactly you heard, and when, so we can keep
our ears ready?
On Aug 22, 2012, at 11:30, Brad Dye b...@braddye.com wrote:
Thought you guys might like to read this and maybe send them some more
reports:
-Original Message-
From: Brad Dye [
Hi:
What is the temp chip reading? Is it reading the oven temperature or just
the ambient temperature?
Ron
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Azelio Boriani
Sent: Friday, August 17, 2012 7:57 AM
To: Discussion of precise
Hi:
What is the temp chip reading? Is it reading the oven temperature or just
the ambient temperature?
Ron
The DS1620 thermometer chip is in the corner of the pc board next to the
RS232 connector and diagonally opposite the OXCO so it reads ambient
temperature.
-Arthur
Hi Bjorn
Mine did come from a UK Ebay seller in Scotland, just under four years ago,
and he told me at that time he had two more and we'd originally discussed
swapping those two for a radio, until the first one arrived and my
enthusiasm tailed off a bit:-)
It's been a while since I've
Once the gain stages enter saturation their noise contribution decreases
significantly in a well designed limiter stage.
The noise contribution is assumed to be zero in this state by the
Collins paper.
In practice, at least for low frequency limiters, power supply noise may
be an issue if the
In a message dated 22/08/2012 19:21:03 GMT Daylight Time, gandal...@aol.com
writes:
With regards to the Oncore VP carrier phase measurement option, I'm not
too sure that the 8821B does actually make use of that.
My 8821B, manufactured in 1999, does contain the 8 channel Oncore VP
Yes, ambient/board temperature, not the OCXO oven temperature.
On Wed, Aug 22, 2012 at 8:12 PM, Arthur Dent golgarfrinc...@yahoo.comwrote:
Hi:
What is the temp chip reading? Is it reading the oven temperature or just
the ambient temperature?
Ron
The DS1620 thermometer chip is in the
Hi Nigel,
With regards to the Oncore VP carrier phase measurement option, I'm not
too sure that the 8821B does actually make use of that.
The Z is a pure software option, to enable the phase capability already
in all of the VP receivers. So you pay extra, but get exactly the same
hardware.
I have one of the atomic clocks that sets itself via WWVB to keep time.
Yesterday, Tuesday, AM it was an hour fast. Today it went back an hour to
the correct time.
Strange.
Tom
- Original Message -
From: KD0GLS kd0...@mninter.net
To: Discussion of precise time and frequency
You can discipline a HP 5065A easily using a Shera with the Tbolt 1 PPS
and a LTC 1655 DAC in stead of an AD 1861.
Bert Kehren.
In a message dated 8/22/2012 8:23:06 A.M. Eastern Daylight Time,
jlt...@att.net writes:
Edgardo,
Congrats on getting the 5065A up and operational. Make sure
The DS1620 is located just behind the RS-232 connector. This is on the
far corner from the oscillator.
Mike
On 8/22/2012 12:59 PM, Ron Ward wrote:
Hi:
What is the temp chip reading? Is it reading the oven temperature or just
the ambient temperature?
Ron
-Original Message-
From:
Wow, what a view. How does the advice go, Don't look down?
On 8/22/2012 9:22 AM, Poul-Henning Kamp wrote:
http://www.jan-mayen.no/
press news
Look for 21. august.
The last picture is particularly interesting:
http://www.jan-mayen.no/nyhet/2012/08_august/C-%20mast/C-mast%208b.JPG
In a message dated 22/08/2012 21:30:36 GMT Daylight Time, b...@lysator.liu.se
writes:
Hi Nigel,
With regards to the Oncore VP carrier phase measurement option, I'm not
too sure that the 8821B does actually make use of that.
The Z is a pure software option, to enable the phase
The amount of jitter verses logic family is all over the place as well.
Take a look at an LS verses an HCT vs an S family and you will see what I mean.
Some of them are very nasty, and are not all created equally.
Jerry
At 09:58 AM 8/22/2012, you wrote:
I was not measuring cycle to cycle jitter
Edgardo congratulations. The 5065 is a really nice unit. I have one also
but earlier and luckily my manuals are on the internet.
It could be disciplined but the fact is for me at least I do not want to.
Leave a great device as is. There are lots of cheap RBs around and even
nice oscillators that
Great pix.
Thanks. My tower isn't quite that large. Look at the cables!
Regards
Paul
WB8TSL
On Wed, Aug 22, 2012 at 8:01 PM, Michael Blazer mbla...@satx.rr.com wrote:
Wow, what a view. How does the advice go, Don't look down?
On 8/22/2012 9:22 AM, Poul-Henning Kamp wrote:
There is a thread on http://tech.groups.yahoo.com/group/FMT-nuts/ with many
observations of WWV reporting the wrong time. Here is a clip of just one of
them:
FYI,
I tuned into WWV this evening (August 19, 2012 UTC), and was surprised to hear
the station making some incorrect audio time
jmulc...@cox.net said:
The amount of jitter verses logic family is all over the place as well. Take
a look at an LS verses an HCT vs an S family and you will see what I mean.
Some of them are very nasty, and are not all created equally.
Is there any collection of hard data? How much does it
Brad;
I believe there are plans to eventually phase in a more reliable phase
modulation/demodulation system.
In fact testing is being performed this week which may affect more
critical receivers (other than inexpensive Atomic Clock stuff).
http://www.nist.gov/pml/div688/grp40/wwvb.cfm
--
This is true and I am actually watching and trying to correct for the wwvb
phase modulation.
Though more work to be done.
Regards
Paul
WB8TSL
On Wed, Aug 22, 2012 at 10:02 PM, Joe Leikhim jleik...@leikhim.com wrote:
Brad;
I believe there are plans to eventually phase in a more reliable phase
On Wed, Aug 22, 2012 at 11:27 PM, Chris Albertson albertson.ch...@gmail.com
wrote:
It is very hard to write a divers in software. You have to use assembly
language and you have to mmake sure that EVERY path in every branch is has
exactly the same number of clock cycles. And then you have
Hi:
Thanks for your quick response to my questions.
I read here that there was information on controlling Thunderbolt's
temperature using the thunderbolt as a PID temperature controller. Would a
constant temperature for the thunderbolt produce a significant improvement
in performance?
I don't
Tom Miller wrote.
I have one of the atomic clocks that sets itself via WWVB to keep time.
Yesterday, Tuesday, AM it was an hour fast. Today it went back an hour to
the correct time.
I also have one of those and it occasionally gets an hour off. It usually
corrects itself at midnight.
I don't know how to search the Time-Nut archive for specific information.
From the headers that are normally not displayed by most mail systems:
List-archive: http://www.febo.com/pipermail/time-nuts
Google also works nicely.
--
These are my opinions. I hate spam.
Hi again:
Okay.
Thanks!
Ron
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Hal Murray
Sent: Wednesday, August 22, 2012 8:55 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] T-Bolt Temperature
I
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