[time-nuts] Z3805A as source for NTPd?

[David Gravereaux]

Hi,

I started going through the docs and got a bit confused regarding
[ldattach] for creating a PPS source.

http://www.manualpages.de/OpenBSD/OpenBSD-5.0/man8/ldattach.8.html

port2 output would have been perfect to use, but ldattach doesn't have a
discipline for this binary format.

I was playing around decoding it in the Tcl scripting language and find
the data to be perfectly useful.  I might put the 1PPS signal on the CD
or DCD pin, though.

http://wiki.tcl.tk/41742

Off hand, I think there's an SCPI module for NTP that will get time off
of port1, but I'd prefer to leave that for alone for user control.

Not sure how to proceed.  Please advise :)

-- 
davyg...@pobox.com:~$ make war
make: *** No rule to make target `war'.  Stop.



signature.asc
Description: OpenPGP digital signature
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Symmetricom experts?

[Majdi S. Abbas]

On Wed, Sep 30, 2015 at 04:21:29PM +0100, Lists wrote:
> It was a bit strange because I had already checked the PSU with a 
> multimeter and all rails read fine. It wasn’t until I put a ‘scope on the 
> supply rails out of interest that I noticed the 5v rail had a massive high 
> freq ripple on it (I guess from the switch mode osc).

A scope is definitely a very handy device and I've regretted not
wheeling the cart over and using it when I should have...but for an 
unscientific swag at ripple, consider putting your meter in AC mode when
testing PSUs, and if you get any crazy high value you may have bad
filter caps.

--msa
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] TASS Computer-Controlled Switch System

[Tom Van Baak]

John,

Thanks for making this available. I can only imagine the amount of work that 
went into it. Having used many of the same HP RF GPIB switches as you over the 
years to do multi-device routing and timing, the TASS geometry is very clever; 
several steps above what HP did. The decision to use the Arduino shield 
form-factor is spot on. I suppose we are all now imagining multiple layers of 
Time & Frequency shields.

The first person to put a sub-ns PICTIC II on a shield gets a special prize.

A year ago I thought this was just a T project but I see you neatly evolved 
it to a generic ham tool as well. Hopefully that community will help make this 
a success.

One question -- because of cable or load changes do you see any noise or 
disturbance on the first or second reading after you change the switches? Also, 
what's the rated lifetime of the switches?

Thanks,
/tvb


- Original Message - 
From: "John Ackermann N8UR" 
To: "Discussion of precise time and frequency measurement" 
; 
Sent: Sunday, September 27, 2015 7:19 AM
Subject: [time-nuts] TASS Computer-Controlled Switch System


> Every so often, I hijack the list to do some shameless self-promotion 
> when I think it would be of interest to the 'nuts community.
> 
> I've spent the last several months developing a computer-controlled 
> relay switch system.  The impetus was failure of the old HP 59307A GPIB 
> switches in my PPS measurement system and discovery that replacement 
> relays are unobtainium.  The only similar remote switches I could find 
> cost >$1K, which seemed a bit rich.  So, I decided to roll my own.
> 
> We ended up with an 8 port switch board controlled by an Arduino.  I 
> think it will have lots of T applications as well as usefulness in ham 
> shacks.  Like virtually everything I do, it ended up as a TAPR kit.
> 
> There's an introductory video at https://youtu.be/P-TUM2dOi4c
> 
> The relay board kit is $119 and we have a shield for the Arduino Mega 
> 2560 that can control 4 relay boards and costs $19.  The software is 
> open source.The boards are now available from TAPR at
> http://tapr.org/kits_tass.html
> 
> (BTW, I contribute my designs to TAPR and don't have any financial 
> interest in sales.)
> 
> Special thanks to time-nuts Bob Camp and Tom Holmes for a lot of 
> engineering assistance.
> 
> Here's the TAPR product announcement:
> 
> "
> Now Available: The TASS Computer-Controlled Switch System
> 
> The TASS (Totally Awesome Switch System) is a general purpose 8 port 
> DC-150 MHz relay-based switch. The hardware is designed to be very 
> generic, with an inexpensive processor such as an Arduino providing the 
> system logic. Control is via USB, with ethernet and other interfaces 
> also available.
> 
> The TASS can be configured several ways, and multiple boards can be 
> combined to create large switching systems. The TASS has many uses, from 
> switching signal sources on a test bench or in a laboratory, to 
> selecting receive antennas and filters in a ham or SWL station.
> 
> The TASS system has two boards:
> 
> *  The TASS-R relay board, which does the mechanics of signal switching 
> and provides a very simple 10-pin interface.
> 
> *  The TASS-SHIELD board for use with an Arduino Mega 2560 
> microcontroller. The TASS-SHIELD allows up to four TASS-R boards to be 
> controlled simultaneously.
> 
> Both boards are available now from TAPR as kits.  They use through-hole 
> parts and don't require any special assembly techniques.
> 
> The final component is open source software for the Arduino that acts as 
> an interface between a host computer or other input system, and the 
> switching hardware.  The software is available for download from TAPR.
> 
> 
> An introductory video is available at
> https://youtu.be/P-TUM2dOi4c
> or from TAPR at
> http://tapr.org/~n8ur/TASS/TASS_Intro_26Sep15.mp4
> 
> Software and documentation can be downloaded from
> http://tapr.org/~n8ur/TASS.
> 
> You may order the TASS-R and TASS-SHIELD boards by visiting
> http://tapr.org/kits_tass.html
> "
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Z3805A firmware?

[Bob Benward]

Not sure if this is the same problem but my Z3801 seems to have the same
problem.  It doesn't run long due to the 10811 crapping out after a hour,
but even leaving it on, the date never seems to update.  It's stuck
somewhere around 1996 (wild guess).

Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom
>>> Van Baak
>>> Sent: Tuesday, September 29, 2015 1:41 AM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Z3805A firmware?
>>> 
>>> David Gravereaux wrote:
>>> > I've had my unit off and in the closet for quite some time, then
>>> > played around with it yesterday.  :GPS:INIT:DATE wasn't taking
>>> > 2015,09,28 and kept returning E-222 "data out of range" and was stuck
>>> > in 1996.  A few power cycles and it got to 2007.  A few more power
>>> > cycles and finally it got it right.
>>> >
>>> > Is this that 1025 week epoch thing?
>>> 
>>> Good detective work. Yes, it sounds like a GPS 2^10 = 1024 WNRO issue,
but
>>> no one else has ever reported this AFAIK, so it's very curious. Thanks
for
>>> posting. Did you check that the NVRAM battery is good? When you measure
>>> the voltage after power-off, see if it decays over a few seconds or
minutes.
>>> 
>>> List -- if it turns out not to be a NVRAM issue, can anyone else with a
Z3805
>>> try to duplicate David's observation?
>>> 
>>> > Anyway, I was wondering about freshening the firmware if possible
>>> > before I go delving into the embedded project of adding on an NTP and
>>> > PTP grandmaster time server with this as the source.
>>> 
>>> 1)  I've never seen firmware updates for the Z38-series. The problem
some
>>> old GPSDO have (like the Datum TS2100 earlier this year) is usually not
in
>>> instrument firmware anyway; it's in the OEM GPS timing receiver board.
>>> 
>>> 2) A decades-old surplus eBay GPSDO like this is good to absolutely
stunning
>>> for home and casual lab use. But I would avoid using them for embedded,
>>> serious, professional, or life-safety applications. Can you tell us more
what
>>> your application is?
>>> 
>>> Thanks,
>>> /tvb
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10728 - Release Date:
>>> 09/29/15

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] FE-5680B Rubidium and DDS

[Clint Jay]

The 9851 will work with pretty much any clock and give an output but of
course you need a decent speed clock to get a useful range of frequencies.

The handy feature of the 9851 is that it has a clock multiplier built in so
that 30MHz can clock it at its maximum speed and give a useful DC-60MHz
output.

I'm a little past the point where the author is, I'm working my way through
the CPLD dump..

On 30 September 2015 at 20:54, Bryan _  wrote:

> Clint, Yes, same seller. Yes schematic is partial, but it did answer a
> question for me that I posted on eevblog where others suggested removing a
> number of components to feed the 20Mhz to a divider. Looks like its a
> resistor, cap and inductor from the schematic; R1,C1,L1.
> I see, you want to make a easily reprogrammable frequency generator. I
> haven't looked at the datasheet of  the AD9851, but thought it needed a
> 125Mhz crystal. Probably just easier to use a circuit like this.
> http://www.perdrix.co.uk/FrequencyDivider/index.html
>
> http://www.ka7oei.com/FE-5680_diag_1c.gif   (would still need to divide
> first)
> I was planning on the same, but just using the /2 for a 10Mhz out in the
> first link.
> Was always hoping for a easy mod inside the "B", but from the write up
> that was just posted, the author has scoped it pretty well and it appears
> the disappearing 10Mhz appears to be firmware driven.
> Cheers
>
> -=Bryan=-
>
> > Date: Wed, 30 Sep 2015 11:45:49 +0100
> > From: cjaysh...@gmail.com
> > To: time-nuts@febo.com
> > Subject: Re: [time-nuts] FE-5680B Rubidium and DDS
> >
> > Bryan, I think we do, bought from an eBay seller named Fluke.I?
> >
> > I also found that schematic but it's a partial, very useful nonetheless.
> >
> > There's also a dump of the firmware and CPLD so I'm hoping I can make
> some
> > sense of that to work out the CPLD, I'd be happy with a solid 10MHz
> output
> > but to my mind, if I can clock an AD9851 with the 30MHz signal I can get
> > 'as good as' with the same or better performance to the serially
> > programmable DDS module.
> >
> > My thinking may of course be flawed, I'm new to the whole time nut game
> and
> > am learning as I go.
> >
> > The M09 chip seems to be in place of the MAX3232 chip, coupling RX/TX
> from
> > connectors to the CPU, it may be an opto but the package is tiny so it'd
> > not offer much isolation, I'll take another look this evening and work
> out
> > the connections fully.
> >
> > On 29 September 2015 at 21:06, Bryan _  wrote:
> >
> > >
> > >
> > >
> > > Hi Clint:
> > > Looks like we have the identical board. I suspect the XC9572 is turning
> > > off the 10Mhz, although why would it wait for 6 seconds?. And as you
> say
> > > it's not related to the "lock" . Here is a schematic I found for a
> FE-5680A.
> > >
> > >
> http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_schematics_v0.1.pdf
> > > I also note the same strange chip in the middle of the absent Max233,
> > > wonder if it is some type of optoisolator to protect
> > > inputs/outputs?Although not sure why one would be needed if the MAX232
> is
> > > unpopulated.
> > >
> > > -=Bryan=-
> > >
> > > > Date: Tue, 29 Sep 2015 15:41:37 +0100
> > > > From: cjaysh...@gmail.com
> > > > To: time-nuts@febo.com
> > > > Subject: Re: [time-nuts] FE-5680B Rubidium and DDS
> > > >
> > > > I've made some investigations and re-confirmed my earlier findings
> on the
> > > > FE-5680B I have.
> > > >
> > > > It locks from cold in under five minutes and runs at approximately
> 700mA
> > > > steady with the expected PPS signal on the output connector when
> locked.
> > > >
> > > > The particular 5680 I have has a Hi Density 15p male connector on the
> > > > output and uses a single 15V supply, part number FE5680B UN 77672.
> > > >
> > > > The device does not have the optional DDS daughterboard which means
> that
> > > > it's not usable as a programmable signal source as it stands (but see
> > > > later).
> > > >
> > > > For approximately six seconds after power is applied a 10MHz signal
> > > > available on the output connector, this signal comes directly from
> the
> > > > XC9572 CPLD via a filter network and appears to be a clean sine wave.
> > > >
> > > > The 10MHz signal seems to be 'switched off' by some event in the
> unit, I
> > > > don't yet know if this is in response to an event or just a timed
> > > shutdown
> > > > but power cycling the unit re-enables the 10MHz output for a further
> six
> > > > seconds. It doesn't appear to be related to rubidium lock as it takes
> > > > consdierably longer than six seconds to lock.
> > > >
> > > > There is a solid 30MHz signal inside the unit, stable once the
> rubidium
> > > has
> > > > locked and the PPS output is also available once locked.
> > > >
> > > > Other observations show that the MAX3232 serial driver chip is
> missing
> > > and
> > > > in it's place there is a tiny 8 pin device marked M09 or MO9 which is
> > > > connected to the TXD/RXD pins on the 

Re: [time-nuts] Possible GPS Interference test

[John Ackermann N8UR]

A long, long time ago I captured a solar flare while monitoring GPS 
signal strength:


http://febo.com/pages/gps_solar_flare/

There was a very significant drop in signal level.  Unfortunately, I 
wasn't able to capture any phase data that corresponded to the event.


John


On 9/30/2015 3:15 PM, Mike Millen wrote:

Would this sunspot activity have anything to do with it?

http://spaceweather.com/

Mike


On 30/09/2015 18:18, Tim Shoppa wrote:

I went ahead and did the math based on some of your numbers. I was a
little
unclear on which numbers to use.

-2E-10 in frequency over 5 minutes, is -60ns. 60ns is not completely
unreasonable for an ionospheric delay variation over hours, but I
think it
would be unusual for there to be so much tumult in just 5 minutes though.
(Especially when geophysical K index has been particularly calm lately.)

On the other hand, -2E-10 over 3 hours, is -2 microseconds which is just
huge!

Do you have anything like a graph of phase difference or EFC over those 3
hours?

Tim N3QE

On Wed, Sep 30, 2015 at 1:54 AM, James Flynn 
wrote:


I recorded apparent anomalous activity on the GPS signal received
near Los
Angeles from about 0200Z to 0500Z 30 Sept. The 1PPS received signal
shifted by -2E-10 in frequency (5 minute averages).

There is a notice on the GPS website about possible interference
today (29
Sept) through 30 Sept in the area of 253 nm around China Lake, CA.
(which
includes Los Angeles)

Anyone else near LA notice anything?



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] FE-5680B Rubidium and DDS

[Bryan _]

Clint, Yes, same seller. Yes schematic is partial, but it did answer a question 
for me that I posted on eevblog where others suggested removing a number of 
components to feed the 20Mhz to a divider. Looks like its a resistor, cap and 
inductor from the schematic; R1,C1,L1.
I see, you want to make a easily reprogrammable frequency generator. I haven't 
looked at the datasheet of  the AD9851, but thought it needed a 125Mhz crystal. 
Probably just easier to use a circuit like this.
http://www.perdrix.co.uk/FrequencyDivider/index.html

http://www.ka7oei.com/FE-5680_diag_1c.gif   (would still need to divide first)
I was planning on the same, but just using the /2 for a 10Mhz out in the first 
link.
Was always hoping for a easy mod inside the "B", but from the write up that was 
just posted, the author has scoped it pretty well and it appears the 
disappearing 10Mhz appears to be firmware driven. 
Cheers

-=Bryan=-

> Date: Wed, 30 Sep 2015 11:45:49 +0100
> From: cjaysh...@gmail.com
> To: time-nuts@febo.com
> Subject: Re: [time-nuts] FE-5680B Rubidium and DDS
> 
> Bryan, I think we do, bought from an eBay seller named Fluke.I?
> 
> I also found that schematic but it's a partial, very useful nonetheless.
> 
> There's also a dump of the firmware and CPLD so I'm hoping I can make some
> sense of that to work out the CPLD, I'd be happy with a solid 10MHz output
> but to my mind, if I can clock an AD9851 with the 30MHz signal I can get
> 'as good as' with the same or better performance to the serially
> programmable DDS module.
> 
> My thinking may of course be flawed, I'm new to the whole time nut game and
> am learning as I go.
> 
> The M09 chip seems to be in place of the MAX3232 chip, coupling RX/TX from
> connectors to the CPU, it may be an opto but the package is tiny so it'd
> not offer much isolation, I'll take another look this evening and work out
> the connections fully.
> 
> On 29 September 2015 at 21:06, Bryan _  wrote:
> 
> >
> >
> >
> > Hi Clint:
> > Looks like we have the identical board. I suspect the XC9572 is turning
> > off the 10Mhz, although why would it wait for 6 seconds?. And as you say
> > it's not related to the "lock" . Here is a schematic I found for a FE-5680A.
> >
> > http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_schematics_v0.1.pdf
> > I also note the same strange chip in the middle of the absent Max233,
> > wonder if it is some type of optoisolator to protect
> > inputs/outputs?Although not sure why one would be needed if the MAX232 is
> > unpopulated.
> >
> > -=Bryan=-
> >
> > > Date: Tue, 29 Sep 2015 15:41:37 +0100
> > > From: cjaysh...@gmail.com
> > > To: time-nuts@febo.com
> > > Subject: Re: [time-nuts] FE-5680B Rubidium and DDS
> > >
> > > I've made some investigations and re-confirmed my earlier findings on the
> > > FE-5680B I have.
> > >
> > > It locks from cold in under five minutes and runs at approximately 700mA
> > > steady with the expected PPS signal on the output connector when locked.
> > >
> > > The particular 5680 I have has a Hi Density 15p male connector on the
> > > output and uses a single 15V supply, part number FE5680B UN 77672.
> > >
> > > The device does not have the optional DDS daughterboard which means that
> > > it's not usable as a programmable signal source as it stands (but see
> > > later).
> > >
> > > For approximately six seconds after power is applied a 10MHz signal
> > > available on the output connector, this signal comes directly from the
> > > XC9572 CPLD via a filter network and appears to be a clean sine wave.
> > >
> > > The 10MHz signal seems to be 'switched off' by some event in the unit, I
> > > don't yet know if this is in response to an event or just a timed
> > shutdown
> > > but power cycling the unit re-enables the 10MHz output for a further six
> > > seconds. It doesn't appear to be related to rubidium lock as it takes
> > > consdierably longer than six seconds to lock.
> > >
> > > There is a solid 30MHz signal inside the unit, stable once the rubidium
> > has
> > > locked and the PPS output is also available once locked.
> > >
> > > Other observations show that the MAX3232 serial driver chip is missing
> > and
> > > in it's place there is a tiny 8 pin device marked M09 or MO9 which is
> > > connected to the TXD/RXD pins on the output connector and the TXD/RXD
> > pins
> > > on the 80C323 CPU.
> > >
> > > I'd be very interested in suggestions as to the part number of that
> > device,
> > > it may yield clues as to the communication method needed.
> > >
> > > Attempts to communicate with it via a terminal program have given no
> > > responses at several 'standard' baud rates. Voltage levels are LVTTL.
> > >
> > > I'm wary of applying 5V to any of the pins on the interface connector
> > > directly and probing them with 3.3v via a 10K resistor has made no
> > > difference to any of the signals I can monitor (30MHz, PPS etc.) with the
> > > exception of pin 13 which I *think* is reset, obviously this 

Re: [time-nuts] Possible GPS Interference test

[Mike Millen]

Would this sunspot activity have anything to do with it?

http://spaceweather.com/

Mike


On 30/09/2015 18:18, Tim Shoppa wrote:

I went ahead and did the math based on some of your numbers. I was a little
unclear on which numbers to use.

-2E-10 in frequency over 5 minutes, is -60ns. 60ns is not completely
unreasonable for an ionospheric delay variation over hours, but I think it
would be unusual for there to be so much tumult in just 5 minutes though.
(Especially when geophysical K index has been particularly calm lately.)

On the other hand, -2E-10 over 3 hours, is -2 microseconds which is just
huge!

Do you have anything like a graph of phase difference or EFC over those 3
hours?

Tim N3QE

On Wed, Sep 30, 2015 at 1:54 AM, James Flynn  wrote:


I recorded apparent anomalous activity on the GPS signal received near Los
Angeles from about 0200Z to 0500Z 30 Sept. The 1PPS received signal
shifted by -2E-10 in frequency (5 minute averages).

There is a notice on the GPS website about possible interference today (29
Sept) through 30 Sept in the area of 253 nm around China Lake, CA. (which
includes Los Angeles)

Anyone else near LA notice anything?



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Possible GPS Interference test

[Hal Murray]

> Anyone else near LA notice anything?

I'm in Silicon Valley.  I got wiped out by tests from China Lake a while ago. 
 I didn't see anything this time.

Anybody know anything about the directionality of the testing?


> The 1PPS received signal shifted by -2E-10 in frequency (5 minute
> averages).

What sort of gear did that?  Was it a GPSDO that went into holdover?  Has it 
gone into holdover at other times?



-- 
These are my opinions.  I hate spam.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] FE-5680B Rubidium and DDS

[Clint Jay]

Bryan, I think we do, bought from an eBay seller named Fluke.I?

I also found that schematic but it's a partial, very useful nonetheless.

There's also a dump of the firmware and CPLD so I'm hoping I can make some
sense of that to work out the CPLD, I'd be happy with a solid 10MHz output
but to my mind, if I can clock an AD9851 with the 30MHz signal I can get
'as good as' with the same or better performance to the serially
programmable DDS module.

My thinking may of course be flawed, I'm new to the whole time nut game and
am learning as I go.

The M09 chip seems to be in place of the MAX3232 chip, coupling RX/TX from
connectors to the CPU, it may be an opto but the package is tiny so it'd
not offer much isolation, I'll take another look this evening and work out
the connections fully.

On 29 September 2015 at 21:06, Bryan _  wrote:

>
>
>
> Hi Clint:
> Looks like we have the identical board. I suspect the XC9572 is turning
> off the 10Mhz, although why would it wait for 6 seconds?. And as you say
> it's not related to the "lock" . Here is a schematic I found for a FE-5680A.
>
> http://www.rhodiatoce.com/pics/time-nuts/FE-5680A/FE-5680A_schematics_v0.1.pdf
> I also note the same strange chip in the middle of the absent Max233,
> wonder if it is some type of optoisolator to protect
> inputs/outputs?Although not sure why one would be needed if the MAX232 is
> unpopulated.
>
> -=Bryan=-
>
> > Date: Tue, 29 Sep 2015 15:41:37 +0100
> > From: cjaysh...@gmail.com
> > To: time-nuts@febo.com
> > Subject: Re: [time-nuts] FE-5680B Rubidium and DDS
> >
> > I've made some investigations and re-confirmed my earlier findings on the
> > FE-5680B I have.
> >
> > It locks from cold in under five minutes and runs at approximately 700mA
> > steady with the expected PPS signal on the output connector when locked.
> >
> > The particular 5680 I have has a Hi Density 15p male connector on the
> > output and uses a single 15V supply, part number FE5680B UN 77672.
> >
> > The device does not have the optional DDS daughterboard which means that
> > it's not usable as a programmable signal source as it stands (but see
> > later).
> >
> > For approximately six seconds after power is applied a 10MHz signal
> > available on the output connector, this signal comes directly from the
> > XC9572 CPLD via a filter network and appears to be a clean sine wave.
> >
> > The 10MHz signal seems to be 'switched off' by some event in the unit, I
> > don't yet know if this is in response to an event or just a timed
> shutdown
> > but power cycling the unit re-enables the 10MHz output for a further six
> > seconds. It doesn't appear to be related to rubidium lock as it takes
> > consdierably longer than six seconds to lock.
> >
> > There is a solid 30MHz signal inside the unit, stable once the rubidium
> has
> > locked and the PPS output is also available once locked.
> >
> > Other observations show that the MAX3232 serial driver chip is missing
> and
> > in it's place there is a tiny 8 pin device marked M09 or MO9 which is
> > connected to the TXD/RXD pins on the output connector and the TXD/RXD
> pins
> > on the 80C323 CPU.
> >
> > I'd be very interested in suggestions as to the part number of that
> device,
> > it may yield clues as to the communication method needed.
> >
> > Attempts to communicate with it via a terminal program have given no
> > responses at several 'standard' baud rates. Voltage levels are LVTTL.
> >
> > I'm wary of applying 5V to any of the pins on the interface connector
> > directly and probing them with 3.3v via a 10K resistor has made no
> > difference to any of the signals I can monitor (30MHz, PPS etc.) with the
> > exception of pin 13 which I *think* is reset, obviously this causes the
> > frequencies to skew for a few seconds until reset is completed.
> >
> > My intent is to use the 30MHz signal from the CPLD to clock a DDS chip
> > (probably one of the eBay DDS modules) that's controlled by a PIC chip (I
> > already have code to run a DDS VFO I developed earlier this and late last
> > year. Hopefully this will be small enough to fit inside the casing
> though I
> > don't see a problem with bringing the 30MHz signal out if necessary.
> >
> > My apologies if this is outside of the scope of this list, I will also be
> > writing up my findings and experiments with this standard on my blog if
> > anyone is interested?
> >
> >
> >
> > On 26 September 2015 at 11:23, Bryan _  wrote:
> >
> > > Thanks Hal, that's interesting, will try and see how far I can get.
> > > -=Bryan=-
> > >
> > > > To: time-nuts@febo.com
> > > > From: hmur...@megapathdsl.net
> > > > Date: Fri, 25 Sep 2015 23:40:40 -0700
> > > > CC: hmur...@megapathdsl.net
> > > > Subject: Re: [time-nuts] FE-5680B Rubidium and DDS
> > > >
> > > >
> > > > > I as well wish there was a quick way of converting it back to
> 10Mhz. I
> > > am
> > > > > sure it can be done, just not sure how or where to look
> > > >
> > > > If the 10 MHz 

Re: [time-nuts] TASS Computer-Controlled Switch System

[John Ackermann N8UR]

Oh, and also to your question about load changes:

a) the RF connections on the board are all 50 ohm stripline and have a 
pretty good match.  At VHF frequencies, the topology results in a 
transmission line stub effect which does limit the high end of the 
frequency range.  The PCB is 4 layers to allow for true stripline layout.


(b) there are 50 ohm termination resistors on all the non-selected 
inputs, so you're not switching from an open circuit condition.


John


On 9/30/2015 9:17 AM, John Ackermann N8UR wrote:

Thanks, Tom.  These sorts of projects are why I disappear from the list
every now and then -- what started out as an afternoon tearing apart one
of the HP switches turned into a major design project, and the other
stuff fell by the wayside.

The Arduino platform ended up being a great choice.  There are so many
widgets available (along with support libraries) that adding bells and
whistles is easy.  I'd never done a line of graphics coding in my life,
but I was able to write the touchscreen interface in a weekend.  Adding
ethernet connectivity took an afternoon, and I expect WiFi won't take
any longer.

I'm also glad I made the decision to put absolutely zero intelligence on
the switch board itself.  One of the SDR radios widely used in the ham
community provides 7 open collector control signals that can be set
based on frequency band.  It turns out that a pair of 3 bit decoder
chips are all that's needed to let that radio fully control the switch,
with no Arduino required.

I haven't tested the dynamic switch performance as you suggested.
However, the relay set time is <3ms so in most cases there should be
ample time for things to settle down.

The relays have a rated 5e7 mechanical operation lifetime, and 1e5
switch-at-full load (~30W) operations.  They've a very standard
form-factor and are available from at least a couple of sources.

(And by the way, early on there was lots of discussion about solid-state
switches, etc., but to meet the requirement of handling DC-150MHz with
no clipping or distortion issues, mechanical relays were the only choice.)

John


On 9/30/2015 1:23 AM, Tom Van Baak wrote:

John,

Thanks for making this available. I can only imagine the amount of
work that went into it. Having used many of the same HP RF GPIB
switches as you over the years to do multi-device routing and timing,
the TASS geometry is very clever; several steps above what HP did. The
decision to use the Arduino shield form-factor is spot on. I suppose
we are all now imagining multiple layers of Time & Frequency shields.

The first person to put a sub-ns PICTIC II on a shield gets a special
prize.

A year ago I thought this was just a T project but I see you neatly
evolved it to a generic ham tool as well. Hopefully that community
will help make this a success.

One question -- because of cable or load changes do you see any noise
or disturbance on the first or second reading after you change the
switches? Also, what's the rated lifetime of the switches?

Thanks,
/tvb


- Original Message -
From: "John Ackermann N8UR" 
To: "Discussion of precise time and frequency measurement"
; 
Sent: Sunday, September 27, 2015 7:19 AM
Subject: [time-nuts] TASS Computer-Controlled Switch System



Every so often, I hijack the list to do some shameless self-promotion
when I think it would be of interest to the 'nuts community.

I've spent the last several months developing a computer-controlled
relay switch system.  The impetus was failure of the old HP 59307A GPIB
switches in my PPS measurement system and discovery that replacement
relays are unobtainium.  The only similar remote switches I could find
cost >$1K, which seemed a bit rich.  So, I decided to roll my own.

We ended up with an 8 port switch board controlled by an Arduino.  I
think it will have lots of T applications as well as usefulness in ham
shacks.  Like virtually everything I do, it ended up as a TAPR kit.

There's an introductory video at https://youtu.be/P-TUM2dOi4c

The relay board kit is $119 and we have a shield for the Arduino Mega
2560 that can control 4 relay boards and costs $19.  The software is
open source.The boards are now available from TAPR at
http://tapr.org/kits_tass.html

(BTW, I contribute my designs to TAPR and don't have any financial
interest in sales.)

Special thanks to time-nuts Bob Camp and Tom Holmes for a lot of
engineering assistance.

Here's the TAPR product announcement:

"
Now Available: The TASS Computer-Controlled Switch System

The TASS (Totally Awesome Switch System) is a general purpose 8 port
DC-150 MHz relay-based switch. The hardware is designed to be very
generic, with an inexpensive processor such as an Arduino providing the
system logic. Control is via USB, with ethernet and other interfaces
also available.

The TASS can be configured several ways, and multiple boards can be
combined to create large switching systems. The TASS has many 

Re: [time-nuts] Why would Keysight UK uncertainty measuring 1 MHz be as high as 7.6 Hz?

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 28 August 2015 at 21:48, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkir...@kirkbymicrowave.co.uk> wrote:

> My LCR meter came back from Keysight  UK last week, where it was
> calibrated. This instrument works at various frequencies from 20 Hz to 1
> MHz, so obviously has some sort of oscillator in it. But I don't think the
> absolute accuracy on frequency is important on this, as it does not even
> have the ability to set to an arbitrary frequency. There are only 8000 or
> so steps, and at the high end, some of those steps are more than 100 kHz
> apart!!!  So clearly frequency accuracy on this instrument is not that
> important.
>
> Anyway, the cal certificate, a copy of which I put here
>
>
> http://www.kirkbymicrowave.co.uk/cal_certificates/Keysight-standard-calibration-with-uncertainties-for-4284A-precison-LCR-meter-18-08-2015.pdf
>
> shows on page 5 that it was checked at 1, 8, 20, 80, 400 kHz, and 1 MHz.
> But the uncertainty reported (7.6 Hz) seems extremely high, given they used
> a 53132A counter as a working standard, and a 5071A primary frequency
> standard. Why should the uncertainty be so high? Am I missing something?
>

I don't know if this thread is closed, but I did get a telephone call from
someone at Keysight today, in response to my query on this matter.
Essentially

1) At the particular calibration centre in the UK, the frequency  counter
used would have been locked to an external reference, as are all the
counters they use at that particular calibration centre in the UK. The
reference is an old HP  5071 cesium, which is regularly compared with GPS.
Their best uncertainty is 5 x 10^-13.

2) The LCR meter tolerance on the 1 MHz is +/- 100 Hz. This means it does
not need a particularly good counter.

3) To enable Keysight to use one calibration procedure world-wide, that
calibration procedure is written to allow the uncertainty to be as high as
the worst case with a counter running on its own internal oven.

So in essence, the meter when calibrated in the UK would have been measured
to far better than the +/- 7.6 Hz indicated on the calibration certificate.
but by specifying +/- 7.6 Hz, it allows the same procedure to be used
anywhere in the world.

Dave
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] TASS Computer-Controlled Switch System

[John Ackermann N8UR]

Thanks, Tom.  These sorts of projects are why I disappear from the list 
every now and then -- what started out as an afternoon tearing apart one 
of the HP switches turned into a major design project, and the other 
stuff fell by the wayside.


The Arduino platform ended up being a great choice.  There are so many 
widgets available (along with support libraries) that adding bells and 
whistles is easy.  I'd never done a line of graphics coding in my life, 
but I was able to write the touchscreen interface in a weekend.  Adding 
ethernet connectivity took an afternoon, and I expect WiFi won't take 
any longer.


I'm also glad I made the decision to put absolutely zero intelligence on 
the switch board itself.  One of the SDR radios widely used in the ham 
community provides 7 open collector control signals that can be set 
based on frequency band.  It turns out that a pair of 3 bit decoder 
chips are all that's needed to let that radio fully control the switch, 
with no Arduino required.


I haven't tested the dynamic switch performance as you suggested. 
However, the relay set time is <3ms so in most cases there should be 
ample time for things to settle down.


The relays have a rated 5e7 mechanical operation lifetime, and 1e5 
switch-at-full load (~30W) operations.  They've a very standard 
form-factor and are available from at least a couple of sources.


(And by the way, early on there was lots of discussion about solid-state 
switches, etc., but to meet the requirement of handling DC-150MHz with 
no clipping or distortion issues, mechanical relays were the only choice.)


John


On 9/30/2015 1:23 AM, Tom Van Baak wrote:

John,

Thanks for making this available. I can only imagine the amount of work that went 
into it. Having used many of the same HP RF GPIB switches as you over the years to 
do multi-device routing and timing, the TASS geometry is very clever; several steps 
above what HP did. The decision to use the Arduino shield form-factor is spot on. I 
suppose we are all now imagining multiple layers of Time & Frequency shields.

The first person to put a sub-ns PICTIC II on a shield gets a special prize.

A year ago I thought this was just a T project but I see you neatly evolved 
it to a generic ham tool as well. Hopefully that community will help make this a 
success.

One question -- because of cable or load changes do you see any noise or 
disturbance on the first or second reading after you change the switches? Also, 
what's the rated lifetime of the switches?

Thanks,
/tvb


- Original Message -
From: "John Ackermann N8UR" 
To: "Discussion of precise time and frequency measurement" ; 

Sent: Sunday, September 27, 2015 7:19 AM
Subject: [time-nuts] TASS Computer-Controlled Switch System



Every so often, I hijack the list to do some shameless self-promotion
when I think it would be of interest to the 'nuts community.

I've spent the last several months developing a computer-controlled
relay switch system.  The impetus was failure of the old HP 59307A GPIB
switches in my PPS measurement system and discovery that replacement
relays are unobtainium.  The only similar remote switches I could find
cost >$1K, which seemed a bit rich.  So, I decided to roll my own.

We ended up with an 8 port switch board controlled by an Arduino.  I
think it will have lots of T applications as well as usefulness in ham
shacks.  Like virtually everything I do, it ended up as a TAPR kit.

There's an introductory video at https://youtu.be/P-TUM2dOi4c

The relay board kit is $119 and we have a shield for the Arduino Mega
2560 that can control 4 relay boards and costs $19.  The software is
open source.The boards are now available from TAPR at
http://tapr.org/kits_tass.html

(BTW, I contribute my designs to TAPR and don't have any financial
interest in sales.)

Special thanks to time-nuts Bob Camp and Tom Holmes for a lot of
engineering assistance.

Here's the TAPR product announcement:

"
Now Available: The TASS Computer-Controlled Switch System

The TASS (Totally Awesome Switch System) is a general purpose 8 port
DC-150 MHz relay-based switch. The hardware is designed to be very
generic, with an inexpensive processor such as an Arduino providing the
system logic. Control is via USB, with ethernet and other interfaces
also available.

The TASS can be configured several ways, and multiple boards can be
combined to create large switching systems. The TASS has many uses, from
switching signal sources on a test bench or in a laboratory, to
selecting receive antennas and filters in a ham or SWL station.

The TASS system has two boards:

*  The TASS-R relay board, which does the mechanics of signal switching
and provides a very simple 10-pin interface.

*  The TASS-SHIELD board for use with an Arduino Mega 2560
microcontroller. The TASS-SHIELD allows up to four TASS-R boards to be
controlled simultaneously.

Both boards are available now from TAPR as 

Re: [time-nuts] Possible GPS Interference test

[Scott McGrath]

I've been in Seattle when a AWACS has been at Boeing and GPS was non functional 
when it was on the ground this took out multiple GPS platforms the on board 
unit in the rental my portable unit plus the one in the iPhone



Content by Scott
Typos by Siri

On Sep 30, 2015, at 6:02 AM, Hal Murray  wrote:

>> Anyone else near LA notice anything?
> 
> I'm in Silicon Valley.  I got wiped out by tests from China Lake a while ago. 
> I didn't see anything this time.
> 
> Anybody know anything about the directionality of the testing?
> 
> 
>> The 1PPS received signal shifted by -2E-10 in frequency (5 minute
>> averages).
> 
> What sort of gear did that?  Was it a GPSDO that went into holdover?  Has it 
> gone into holdover at other times?
> 
> 
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Z3805A as source for NTPd?

[David Gravereaux]

On 09/30/2015 11:16 AM, David Gravereaux wrote:
> Hi,
> 
> I started going through the docs and got a bit confused regarding
> [ldattach] for creating a PPS source.
> 
> http://www.manualpages.de/OpenBSD/OpenBSD-5.0/man8/ldattach.8.html

^-- Oops, old man page not current to the 3.19.x kernel I'm using.

$ sudo ldattach -d -s 9600 -n -8 -1 pps /dev/ttyUSB0
ldattach:opened /dev/ttyUSB0
ldattach:set to raw 9600 8n1: cflag=0xcbd
ldattach:line discipline set to 18

Ok, got that and it created a PPS device.

$ ls /dev/pps*
/dev/pps0


But I think the PPS driver is looking at Carrier Detect to flash rather
than the data that it doesn't understand anyways?


$ sudo ppswatch /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
^C

Total number of PPS signals: 0
Maximum divergence: 0
$

-- 
davyg...@pobox.com:~$ make war
make: *** No rule to make target `war'.  Stop.



signature.asc
Description: OpenPGP digital signature
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] FE-5680B Rubidium and DDS

[cfo]

On Sat, 26 Sep 2015 07:36:30 +0100, Clint Jay wrote:

*** SNIP 
> so it may be
> possible to modify the B version Bryan and I have.
*** SNIP 

Someone just published a 10Mhz writeup on eevblog
http://www.eevblog.com/forum/testgear/fe-5680b-1pps-to-10mhz/30/?
action=post;quote=767280;last_msg=767313

http://andrelubbock.blogspot.co.nz/2015/09/rubidium-frequency-
standard.html

CFO
Denmark

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Possible GPS Interference test

[James Flynn]

Hal Murray  writes:

> 
> What sort of gear did that?  Was it a GPSDO that went into holdover?  
Has it 
> gone into holdover at other times?
> 


I am running a proof of constant test bed comparing time/transfer method 
using another medium with simple GPS time receiver.  I have a disciplined 
double oven crystal oscillator that is generating the 1PPS signal for 
comparison. GPS receiver is a Navman T-60 in position hold mode (timing).

I will see missing pulse errors if the time signal is invalid.  I was not 
seeing those except at very end.  

The anomalous behavior lasted on and off (mostly on) until 1330Z Sept 30 
(this morning). There were large timing errors in the last ten minutes or 
so and then signal seemed to settle down to normal.

I am away from experiment at moment, but what I could check remotely 
indicated everything was running hot, straight and normal.

I will check it again when I get back and put up data.

I have not seen this before but was not running during earlier GPS 
interference tests.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Symmetricom experts?

[Lists]

Thanks to all who replied. Turns out it was the cap in the PSU (3,300uF 10v). I 
replaced it with a 3,300uF 16v and all seems well.

It was a bit strange because I had already checked the PSU with a multimeter 
and all rails read fine. It wasn’t until I put a ‘scope on the supply rails out 
of interest that I noticed the 5v rail had a massive high freq ripple on it (I 
guess from the switch mode osc).

Anyway it’s back up and running now.

Thanks again,
Chris


> On Thu, Sep 24, 2015 at 1:21 AM, G1FEF  wrote:
> 
>> Do we have any Symmetricom experts on this list?
>> 
>> I've had a Symmetricom Syncserver S200 GPS+PPS with rubidium clock running
>> for several years until we had a power cut and the UPS battery failed, on
>> powering back up it won't boot at all.
>> 
>> I suspect the flash is corrupt but they protect it in some way, so one
>> can't just copy the o/s onto a new card, and the company want 's to fix
>> it for me!
>> 
>> Thanks in advance,
>> Chris
>> 
>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] FE-5680B Rubidium and DDS

[Clint Jay]

I *think* that's the method posted by the seller of my unit and it's a
modification requiring an extra chip to divide the 20MHz signal down.

I am hoping to be able to re-enable the original 10MHz signal and use the
original filter as fitted to the board.

Still handy if you need 10MHz though.

On 30 September 2015 at 15:32, cfo  wrote:

> On Sat, 26 Sep 2015 07:36:30 +0100, Clint Jay wrote:
>
> *** SNIP 
> > so it may be
> > possible to modify the B version Bryan and I have.
> *** SNIP 
>
> Someone just published a 10Mhz writeup on eevblog
> http://www.eevblog.com/forum/testgear/fe-5680b-1pps-to-10mhz/30/?
> action=post;quote=767280;last_msg=767313
>
> http://andrelubbock.blogspot.co.nz/2015/09/rubidium-frequency-
> standard.html
>
> CFO
> Denmark
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Clint.

*No trees were harmed in the sending of this mail. However, a large number
of electrons were greatly inconvenienced.*
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.