and one more for the list!
regards,
Paul
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of ewkeh...@aol.com
Sent: 19 November 2012 19:53
To: time-nuts@febo.com
Subject: Re: [time-nuts] Nifty MINI TIC for DMTD work
Don
lets see how
Thanks to Ed, I now have a general brochure and spec sheet. There it mentions
an internal setting resolution (for frequency adjustment). It should be
described in detail the manual.
I kindly inquire again if someone has experience with the adjustment of this
unit or has access to it's manual.
Its actually Tau with a subscript 0.
This is the the time interval between successive measurements.
e.g. if a measurement is taken every second then Tau0 is 1 sec.
Bruce
Edgardo Molina wrote:
Dear John Ackermann,
I find your reply to my request to be very interesting. Without fear of asking.
Hi Edgardo
The original PRFS standard used an FRS module so I suspect yours will too,
but a quick check when it arrives should confirm for sure.
The VRFS standard, which is a VXIbus unit, also uses the FRS, although the
FRT standard used the FRK module.
A quick Google search on Efratom
Greetings
I know that the accuracy of GPS degrades indoors. However, suppose
that I just want to turn a GPS module on, acquire the current time
accurate to a second, and then turn it off. I can get a good deal on
the U-Blox LEA-5H modules (same as used on Arduino shields I think),
which have a
Greetings
I know that the accuracy of GPS degrades indoors. However, suppose
that I just want to turn a GPS module on, acquire the current time
accurate to a second, and then turn it off. I can get a good deal on
the U-Blox LEA-5H modules (same as used on Arduino shields I think),
which have a
Dave
Thank you for your offer. I think I have the documentation solved. Brian,
who helped in the past has offered to help and has some of the previous work
to build on.
As to PIC programming I will ask Juerg to get with you off list.
Bert
In a message dated 11/19/2012 8:47:25 P.M. Eastern
I am interested in one.
- Original Message -
From: cdel...@juno.com
To: time-nuts@febo.com
Sent: Monday, November 19, 2012 8:04 PM
Subject: [time-nuts] Nifty MINI TIC for DMTD work
MINI-TIC for DMTD work
Hi Everyone!
I've been testing a Miniature 2 channel TIC that Bert Kehren
Hi Edgardo --
Sorry, I should have explained. Tau0 is shorthand for the base tau -- the
actual interval between each measurement. You can measure longer tau by simply
using every nth measurement. So tau0 = 1 second simply means you're taking a
reading once per second.
John
On Nov 20,
Hi
I believe the lowest cost approach is to take the RF and run it through an
simple switch. The switch either has a 0 degree or a 180 degree phase shift.
Drive the control of the switch with a computer generated track of the known
modulation format. Let the computer get time via NTP and just
Great thread.
Bob in the d-psk-r thats exactly what I am doing is flipping a switch on
the incoming signal.
That normalizes it. However in its current approach it is random as either
0 or 180 out always. No attempt has been made to determine 0. But it does
run the phase tracking rcvrs fine. That
I don't think GPS is ever so in accurate as to have a 1 second error. If
it has a solution at all it is going to be at least within a millisecond.
The way everyone handles holdover (Holdover is timekeeping with GPS is
not available) is to keep a local clock driven off a stable oscillator.
Then
I have checked my inventory and I have boards and parts for a couple of
dual mixers and counters. I will work with some ones that are willing to build
and test them right away and have a good quality OCXO for offset like a
10811 or Morion and a second high performance OCXO for measuring
Hi, Bert,
no problem for the OCXO's (10811, Morion, ALtra CPLD) or other material
or soldering skills. But, to be precise, what is the
Software know
how ?
C-ProteusBasic-MicroC, ecc ?
thanks
Andrea IW2FDH
Il 20/11/2012 17.00, ewkeh...@aol.com ha scritto:
Bert Kehren
be able to handle 56 K RS232 and use AV software, to me that is not
trivial, and Juerg is to busy to hold hands beside me.
Bert
In a message dated 11/20/2012 11:33:44 A.M. Eastern Standard Time, croma6
4...@yahoo.it writes:
Hi, Bert,
no problem for the OCXO's (10811, Morion, ALtra CPLD)
celephi...@gmail.com said:
I know that the accuracy of GPS degrades indoors. However, suppose that I
just want to turn a GPS module on, acquire the current time accurate to a
second, and then turn it off. I can get a good deal on the U-Blox LEA-5H
modules (same as used on Arduino shields I
Hi
Ten seconds a month is wrist watch accuracy at constant temperature. For $3
Maxim will sell you a +/- 2 ppm real time clock. That will hold your 1 second
for 500,000 sec (5.787 days). A cheap cell phone style TCXO at $1 or so should
hold 1 ppm over a modest range. That will get you out
ewkeh...@aol.com wrote:
The D/M is being revisited because of the counter performance. 1 E-13 is
easily attainable but the Czech IREE published a paper and claim 2 E-15.
Do you mean the paper optimization of dual-mixer time-difference
multiplier ?
The ZCD developed in this is a bit of a
Hi
If indoors always includes a view through unshielded windows to towards the
equator, then you might be ok. If it includes pole only facing offices in a
conventional steel structure - not so much. The issue isn't so much time, as
ability to get a good enough signal to lock to. If you add a
Yes Bruce I have the paper. I am not suggesting to copy it verbatim but if
there is a way to reach reasonable priced 1 E-14 members of the list should
pipe in. I am willing to do an other board. the rest of the systems well
on its way. Einally after three years.
Bert Kehren
In a message
Since mixer noise is one of the limiting factors using a mixer with low
flicker noise will help.
NIST found that a custom mixer using diode connected (collector base
short) 2N222As had a significantly lower flicker phase noise than either
the ZRPD1 or the 10534A.
They used off the shelf 1:5
any luck on the ntp server?
On Sat, Nov 10, 2012 at 1:31 AM, David J Taylor
david-tay...@blueyonder.co.uk wrote:
oh thats my kind of basement wall wart. Place it on the wall and forget it.
I have nas drives that way. They spin down and power consumption is I want
to say 5-8 watts been a long
Hi Said,
Look at Dieder's site.
Groet,
Henk
Op 20 nov. 2012 om 02:36 heeft saidj...@aol.com het volgende geschreven:
There is one calibration that can only be started by a GPIB command. I ran
into that, my unit constantly said something like xxx calibration
required or similar during
Dear Bert,
Good afternoon. Nice to hear from you and your current project.
Please count me in when the time comes. Do you have the spec sheet for this
project? I am about to buy the TADD-2 Mini to get a 1PPS signal from my
HP-5065A that does not provide such an output. Whenever you are ready,
I'm interested in two...
Thanks,
Steve
On Nov 19, 2012, at 8:04 PM, cdel...@juno.com wrote:
MINI-TIC for DMTD work
Hi Everyone!
I've been testing a Miniature 2 channel TIC that Bert Kehren and Juerg
Koegel
and Richard Mc Corkle have designed.
It has 9 digits/Sec. and with a
Bert: could you post the schematic, please?
--
From: ewkeh...@aol.com
Sent: Tuesday, November 20, 2012 3:13 PM
To: time-nuts@febo.com
Subject: [time-nuts] An other project
I did mention a MAX 3000 implementation of a 1 pps generator. The
There is no schematic, it is beside the Wenzel all in the MAX 3000 a string
of dividers and depending on what we want selected outputs and all outputs
have synchronizers to the input to reduce jitter.
Bert
In a message dated 11/20/2012 5:22:50 P.M. Eastern Standard Time,
Typical Minicircuits SMT RF amps have a phase noise at best 20dB worse
(@10Hz offset) than the mixer/phase detector.
Their reverse isolation is quite low (40dB)
The principle reason that the Czech DMTD has such low internal noise is
due to the absence of any isolation amplifiers.
They use the
Hi,
I am have thinking / tinkering / planning a wwvb receiver for longer
than I am willing to admit!! It seems to me that one could take a
ferrite loop, JFET buffer, ADC and a small microprocessor to get down to
baseband - say 20 Hz complex sampling rate - and then output on a serial
port
I am an interested party.
Who is coordinating the board orders?
Is there any wiki or a web site details for the project?
Regards
Geoffrey
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Hi
Those isolation numbers are *highly* dependent on very good matching at all
ports. That's rarely the case unless you have a bunch of pads running around
the system.
Bob
On Nov 20, 2012, at 5:49 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote:
Typical Minicircuits SMT RF amps have a
Dave
A couple of comments numbers of folks on Time-nuts have suggested the same
types of approaches. Though outside of an armchair discussion not much
happens. So I believe that what you say is reasonable. Jut remember lots of
the country has poor reception so that really makes life hard.
It was
The details about matching (if any) used in the Czech DMTD would be
informative.
To avoid degrading the performance of the DMTD system below that imposed
by the mixers any isolation amps used will need a flicker phase noise
floor below that of the mixers.
Even an opamp based isolation
Hi
Given that common practice is to mis-match the IF port on the mixers, it's
probably not realistic to depend on exact match for isolation. Simple / cheap
common base buffers likely are a better approach. Lots of isolation and not
much flicker noise.
Bob
On Nov 20, 2012, at 9:01 PM, Bruce
Anyone notice this?:
https://isc.sans.edu/diary.html?nstoryid=14548
Seems a Navy NTP server claimed it was year 2000 for a while.
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To unsubscribe, go to
Yes, Two of my PC's asked if I wanted to change the data and time to -8xxx
days, 0 hours, 0 minutes, 0 seconds. A real head scratcher until I saw the
link below. I believe the time server was tick.usno.navy.mil
The Time Sync software that I use is D4 - see:
http://www.thinkman.com/dimension4/
Yet another... please add me to the list... I'm very interested. Thanks!
On 11/19/2012 2:04 PM, cdel...@juno.com wrote:
MINI-TIC for DMTD work
Hi Everyone!
I've been testing a Miniature 2 channel TIC that Bert Kehren and Juerg
Koegel
and Richard Mc Corkle have designed.
It has 9
Hi
A few more parts and likely not quite as much isolation. None of that means it
won't do a good job though.
Bob
On Nov 20, 2012, at 11:20 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz
wrote:
The attached circuit is somewhat more efficient and a little quieter.
With a little elaboration
Reverse isolation at 10MHz is around 43dB.
This can be improved significantly by using a Sziklai pair instead of a
single transistor in each amplifier.
However one could also do this in a CB amp.
Since phase detectors require LO and RF input levels of around 10dBm
either deign should
Hi
A pair of common base amps will get you to what ever your layout will permit. A
single common base at 10 MHz should get you to at least 60 db with a little
care. If you run a reasonable transistor you can run levels that will fry a 10
or a 13 dbm mixer. Again, all the discrete circuits work
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