Re: [time-nuts] Affordable PoE 6-digit time displays?

[Bob Bownes]

If you can snag something that will put out IRIG-B, there are lots of choices. 

I’m still hunting for something that will take NTP in and put IRIG out. There 
is probably someone doing it with a Pi or an Arduino. 

Bob



> On Jun 14, 2018, at 21:38, Chris Howard  wrote:
> 
> Maybe not exactly, but I use an app on an old Android cell phone as my UTC 
> wall clock. Large characters in horizontal mode; NTP via WiFi.
> 
> 
> 
> 
> ⁣Sent from BlueMail ​
> 
>> On Jun 14, 2018, 20:15, at 20:15, David Andersen  
>> wrote:
>> I'd hoped that ebay or aliexpress would yield a bounty given how
>> seemingly
>> simple these are, but I'm drawing a blank (and finding a lot of $300+
>> new
>> options).  Anyone have a favorite source for either flat wall-mount or
>> rackmount displays that will pull from an NTP/SNTP/whatever server?
>> 
>> (if wall-mount, PoE is optimal).  Used good.  Cheap good.  Looks good
>> next
>> to my random collection of antiquated time measurement gear provides
>> amusement value but isn't really critical. :-)
>> 
>> Thanks!
>> 
>> -Dave
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Re: [time-nuts] Cheap jitter measurements

[Bob Bownes]

Find a nice used 5370/5371? :)

There is a 5371 on ebay for $250 at the moment.

On Tue, Apr 3, 2018 at 1:47 PM, Gary E. Miller  wrote:

> Time-nuts!
>
> With care I can measure GPS jitter on a RasPi to a bit over 300 nano sec
> resolution.  That is the smallest increment of the RasPi 3B clock with
> a 64-bit kernel.  That is clearly not time-nuts accuracy.
>
> What would you guys suggest as the cheapest way to see jitter down to
> around 1 nano second?
>
> I'm thinking maybe something like a rubidium standard (FE-5680A) and
> a TICC-TAPR?  But that would put me out around $400.
>
> The picPET does not look accurate enough.  Maybe a clever way to use it
> for more accuracy?  Is there a picPET like thing cheaper than the
> TICC-TAPR?
>
> Ideas?
>
> RGDS
> GARY
> 
> ---
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
> g...@rellim.com  Tel:+1 541 382 8588
>
> Veritas liberabit vos. -- Quid est veritas?
> "If you can’t measure it, you can’t improve it." - Lord Kelvin
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Re: [time-nuts] Simple open source microcontroller solution to tune DDS needed

[Bob Bownes]

The digispark and digispark pro are also some nice <$15 development boards
that are USB programmable, use the Arduino IDE or AVR compiler, and have
just enough pins to be useful.

On Wed, Dec 13, 2017 at 4:34 PM, jimlux  wrote:

> On 12/13/17 1:28 PM, Jerry Hancock wrote:
>
>> Well, if you haven’t selected a DDS and you need I/Q, I would go with the
>> tried and true 9854 as it has I/Q outputs and I thought a 12bit DAC so the
>> resulting spurs and sfdr are lower than other chips, or were, as I think
>> they have 14bit DACs on other chips now.  It also depends on the highest
>> frequency range needed and power requirements as they all seem to run hot.
>> There is a new DDS, a 9910 I think, that uses a 14bit DAC but it is a
>> single output and would need to sync clocks if you need I/Q.  I have used
>> the 9854 with PIC, Arduino and STM32 and assuming the frequency range is
>> ok, I found it to be the better of the chips.  I don’t think they have a
>> replacement for it (I/Q with 14bit DAC would be great) but I haven’t looked
>> lately.
>>
>> The language is C but I think it has C++ and C# compilers out there.
>> Also, once you have the code tested on the Arduino you can just run it on
>> the equivalent AVR chip and build your own board.  I don’t think there is a
>> license or runtime compiler issue and if there is, I remember seeing a GNU
>> compiler for the AVRs and Arduino.  My only point is that for prototyping
>> and testing, the Arduino seems to be the easiest with tons of support and
>> many, many adapters and I/O,  The STM32 boards are faster but the learning
>> curve is just unbelievable.  It took me months to master those boards
>> compared to minutes for the Arduino.
>>
>>
>
> I agree - $20 for a Teensy, some jumper wires from solder holes on the
> Teensy to your breadboard, load up the Teensyduino libraries into the
> Arduino IDE and your SPI/I2C/serial interface is done.  I did this to write
> arduino code to drive a Silabs part.
>
> If it takes an hour, I'd be surprised (or you have an incredibly slow
> download connection, like doing it on an airplane in the back rows where
> the WiFi is clunky - which I have done).  The hard part when going to a
> standalone design is picking the right pins on the microcontroller (since
> so many have multiple functions, you want to be careful about accidentally
> using something that has another useful function).
>
>
>
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Re: [time-nuts] Why discipline Rubidium oscillator?

[Bob Bownes]

Oops cat hit ‘send’

5071’s I’ve seen for as low as about 9k, but usually in the 15-30 range. I 
don’t want to know what they are new. 

5061’s can be had for under $1000. If you are very lucky, under $500. 

And once you have the standard, you need the counters. And other analysis 
tools...pretty soon your spouse will know you’ve gone off the deep end. 

Anyone want an sr530 lock in amplifier that eats fuses and voltage regulators?

Bob

> On Nov 20, 2017, at 23:50, Jerry Hancock  wrote:
> 
> I read up on the GPS L1/L2 and I think there is an L5.
> 
> And when you say “on the market” the real question is “can be purchased for 
> 1/20th the price of new” like all the other re-purposed toys we buy,
> 
> Regards,
> 
> Jerry
> 
> 
>> On Nov 20, 2017, at 6:43 PM, Dana Whitlow  wrote:
>> 
>> 
> 
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Re: [time-nuts] Why discipline Rubidium oscillator?

[Bob Bownes]

Cost of a cesium clock can go from less than you pay for a pair of doxco‘s to 
many tens of thousands. I think 5071’s are in 

> On Nov 20, 2017, at 23:50, Jerry Hancock  wrote:
> 
> I read up on the GPS L1/L2 and I think there is an L5.
> 
> And when you say “on the market” the real question is “can be purchased for 
> 1/20th the price of new” like all the other re-purposed toys we buy,
> 
> Regards,
> 
> Jerry
> 
> 
>> On Nov 20, 2017, at 6:43 PM, Dana Whitlow  wrote:
>> 
>> 
> 
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Re: [time-nuts] Recommendation for cheap GBIP adapter for Linux

[Bob Bownes]

All GPIB to Ethernet adapters are not created equal. 

The NI GPIB-E is no longer supported for example, only the 100 & 1000. 

Which is very annoying to those that have one. 

Bob



> On Nov 18, 2017, at 17:45, Bob kb8tq  wrote:
> 
> Hi
> 
> Given all the nonsense with USB drivers / “fake" serial chips / OS 
> restrictions …. 
> The ethernet solution makes a lot of sense.
> 
> Bob
> 
>> On Nov 18, 2017, at 4:45 PM, jimlux  wrote:
>> 
>> On 11/18/17 11:04 AM, Attila Kinali wrote:
>>> Hi,
>>> I have a need for a GBIP adapter that I can use with Linux.
>>> It shouldn't be too expensive, but I rather spend a few bucks
>>> more for ease of use. Where "ease of use" means I don't have
>>> problems with weird drivers on Linux (Windows doesn't matter at all).
>>> I do not mind writing my own read-out software (that's quickly and
>>> easily done). What would people here recommend?
>> 
>> I use the Prologix GPIB to Ethernet converters.
>> 
>> Makes it "platform independent" since it's just an IP socket to the outside 
>> world
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Re: [time-nuts] Deaf Z3801

[Bob Bownes]

However, setting it to 23:59:59 Dec 12,2007 and leaving t alone for an hour
or two seems to have done the trick.

Thanks folks! Off to look at adev/pn of the $7 GPS boards I found with
10MHz out. Plots soon.

Bob


On Thu, Nov 16, 2017 at 12:26 PM, Bob Bownes <bow...@gmail.com> wrote:

> Yup. tried that too.
>
> The system won't let me set the date after 23:59:59 Dec 12,2007
>
>
>
> On Thu, Nov 16, 2017 at 11:42 AM, Bob kb8tq <kb...@n1k.org> wrote:
>
>> Hi
>>
>> One thing that has faked me out on SCPI - they cache error messages. You
>> have to dump them all before you try something.
>>
>> Bob
>>
>> > On Nov 16, 2017, at 11:24 AM, Bob Bownes <bow...@gmail.com> wrote:
>> >
>> > Thanks John.
>> >
>> > When I do this, I get the E-222 error indicating 'Data out of range'.
>> >
>> > Tried several formats, trailing';', etc.
>> >
>> > Here's what I get:
>> > scpi > :GPS:INIT:DATE 2017,11,16
>> > E-222> :GPS:INIT:DATE 17,11,16
>> > E-222> :GPS:INIT:DATE 17,01,01
>> > E-222> :GPS:INIT:DATE 2017,01,01
>> > E-222> :GPS:INIT:DATE 2017,01,01;
>> > E-222> :GPS:INIT:DATE 17,01,01;
>> > E-222>
>> >
>> > Even tried a :SYSTEM:PRESET, whic interestingly enough, does not reset
>> the
>> > location.
>> >
>> > Bob
>> >
>> > On Wed, Nov 15, 2017 at 8:49 AM, John Franke <jmfra...@cox.net> wrote:
>> >
>> >> Try:
>> >>
>> >>
>> >> Shut off power to the GPS receiver
>> >>
>> >> Disconnect the GPS antenna downlead
>> >>
>> >> Reapply power to the GPS receiver
>> >>
>> >> Enter  *:GPS:INIT:DATE 2017,01,01* (The only space is between DATE and
>> >> 2017)
>> >>
>> >> Reconnect the GPS antenna downlead and wait
>> >>
>> >>
>> >> John
>> >>
>> >> On November 14, 2017 at 10:43 PM Bob Bownes <bow...@gmail.com> wrote:
>> >>
>> >> I put my 3801 back in service the day before yesterday, or tried to.
>> It’s
>> >> been on the shelf for about a year (off).
>> >>
>> >> I powered it up, and while it sees a few sats, it will not acquire any.
>> >> Changing to a known good antenna (off the NTP server) makes no
>> difference.
>> >>
>> >> Anyone seen the behavior before? The location data is good, but the
>> >> time/date are way out.
>> >>
>> >> Thanks!
>> >> Bob
>> >>
>> >> ___
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>> >> mailman/listinfo/time-nuts
>> >> and follow the instructions there.
>> >>
>> >>
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Re: [time-nuts] Deaf Z3801

[Bob Bownes]

Yup. tried that too.

The system won't let me set the date after 23:59:59 Dec 12,2007



On Thu, Nov 16, 2017 at 11:42 AM, Bob kb8tq <kb...@n1k.org> wrote:

> Hi
>
> One thing that has faked me out on SCPI - they cache error messages. You
> have to dump them all before you try something.
>
> Bob
>
> > On Nov 16, 2017, at 11:24 AM, Bob Bownes <bow...@gmail.com> wrote:
> >
> > Thanks John.
> >
> > When I do this, I get the E-222 error indicating 'Data out of range'.
> >
> > Tried several formats, trailing';', etc.
> >
> > Here's what I get:
> > scpi > :GPS:INIT:DATE 2017,11,16
> > E-222> :GPS:INIT:DATE 17,11,16
> > E-222> :GPS:INIT:DATE 17,01,01
> > E-222> :GPS:INIT:DATE 2017,01,01
> > E-222> :GPS:INIT:DATE 2017,01,01;
> > E-222> :GPS:INIT:DATE 17,01,01;
> > E-222>
> >
> > Even tried a :SYSTEM:PRESET, whic interestingly enough, does not reset
> the
> > location.
> >
> > Bob
> >
> > On Wed, Nov 15, 2017 at 8:49 AM, John Franke <jmfra...@cox.net> wrote:
> >
> >> Try:
> >>
> >>
> >> Shut off power to the GPS receiver
> >>
> >> Disconnect the GPS antenna downlead
> >>
> >> Reapply power to the GPS receiver
> >>
> >> Enter  *:GPS:INIT:DATE 2017,01,01* (The only space is between DATE and
> >> 2017)
> >>
> >> Reconnect the GPS antenna downlead and wait
> >>
> >>
> >> John
> >>
> >> On November 14, 2017 at 10:43 PM Bob Bownes <bow...@gmail.com> wrote:
> >>
> >> I put my 3801 back in service the day before yesterday, or tried to.
> It’s
> >> been on the shelf for about a year (off).
> >>
> >> I powered it up, and while it sees a few sats, it will not acquire any.
> >> Changing to a known good antenna (off the NTP server) makes no
> difference.
> >>
> >> Anyone seen the behavior before? The location data is good, but the
> >> time/date are way out.
> >>
> >> Thanks!
> >> Bob
> >>
> >> ___
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> >>
> >>
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Re: [time-nuts] Deaf Z3801

[Bob Bownes]

Thanks John.

When I do this, I get the E-222 error indicating 'Data out of range'.

Tried several formats, trailing';', etc.

Here's what I get:
scpi > :GPS:INIT:DATE 2017,11,16
E-222> :GPS:INIT:DATE 17,11,16
E-222> :GPS:INIT:DATE 17,01,01
E-222> :GPS:INIT:DATE 2017,01,01
E-222> :GPS:INIT:DATE 2017,01,01;
E-222> :GPS:INIT:DATE 17,01,01;
E-222>

Even tried a :SYSTEM:PRESET, whic interestingly enough, does not reset the
location.

Bob

On Wed, Nov 15, 2017 at 8:49 AM, John Franke <jmfra...@cox.net> wrote:

> Try:
>
>
> Shut off power to the GPS receiver
>
> Disconnect the GPS antenna downlead
>
> Reapply power to the GPS receiver
>
> Enter  *:GPS:INIT:DATE 2017,01,01* (The only space is between DATE and
> 2017)
>
> Reconnect the GPS antenna downlead and wait
>
>
> John
>
> On November 14, 2017 at 10:43 PM Bob Bownes <bow...@gmail.com> wrote:
>
> I put my 3801 back in service the day before yesterday, or tried to. It’s
> been on the shelf for about a year (off).
>
> I powered it up, and while it sees a few sats, it will not acquire any.
> Changing to a known good antenna (off the NTP server) makes no difference.
>
> Anyone seen the behavior before? The location data is good, but the
> time/date are way out.
>
> Thanks!
> Bob
>
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[time-nuts] Deaf Z3801

[Bob Bownes]

I put my 3801 back in service the day before yesterday, or tried to. It’s been 
on the shelf for about a year (off). 

I powered it up, and while it sees a few sats, it will not acquire any. 
Changing to a known good antenna (off the NTP server) makes no difference. 

Anyone seen the behavior before? The location data is good, but the time/date 
are way out. 

Thanks!
Bob
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Re: [time-nuts] Favorite counters (current production)?

[Bob Bownes]

That reminds me, should anyone have a schematic for an SR 830 walking 
amplifier, can you please get in touch with me. I have one that keeps eating 
voltage regulators.

> On Nov 12, 2017, at 12:12, Dr. David Kirkby (Kirkby Microwave Ltd) 
>  wrote:
> 
>> On 10 November 2017 at 16:37, Bob Camp  wrote:
>> 
>> Hi
>> 
>> There is no perfect answer. I’d go with the 53230 simply because it
>> *might* be supported
>> the longest.
>> 
>> Bob
>> 
> 
> 
> If I had to take a bet, I would say the SR620 will be supported longer.
> Stanford Research seem to be selling the same products they have for
> decades. I started my Ph.D. in about 1994, and bought what was a very new
> product - the SR830 lock in amplifier.
> 
> http://www.thinksrs.com/products/SR810830.htm
> 
> 23 years later, it is still a current product.
> 
> Stanford Research also sell a couple of LCR meters
> 
> http://www.thinksrs.com/products/SR715720.htm
> 
> The SR720 looks remarkably like the long obsolete HP E4925A LCR meter.
> 
> There's no doubt in my mind that Stanford Research sell their products much
> longer than HP/Agilent/Keysight. Of course, that does mean Stanford
> Research are using older technology.
> 
> I would add, when I have contacted Keysight about obsolete products they
> have always been helpful. When I contacted Stanford Research to ask what
> was the latest firmware for an SR620, I was ignored. They also ignored some
> other email I sent them. So their support does not seem as good as
> Keysight, but I assume, with persistence, one could get support on a
> current product.
> 
> Dave
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[time-nuts] EIP 371 counter

[Bob Bownes]

I’m trying to put a EIP 371 into talk only mode but have zero documentation. 
Anyone know how to do so so that we can characterize a few oscillators?

Thanks!
Bob
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[time-nuts] Spectracom 9189 options

[Bob Bownes]

Folks,

I've just acquired a spectracom 9189 and can see from the back that
frequency, 1PPS, and IRIG were options. I presume these were add in boards,
but thought I would check with you folks to see if anyone has any knowledge
of the details.

Thank!
Bob
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Re: [time-nuts] Distribution divider/amplifier for 10MHz GPSDO

[Bob Bownes]

Going on recollection. Now I’ll have to go look again. 

> On Oct 23, 2017, at 17:06, Jeremy Elson <jel...@gmail.com> wrote:
> 
>> On Mon, Oct 23, 2017 at 1:49 PM, Bob Bownes <bow...@gmail.com> wrote:
>> 
>> Will it work? Probably. Up to a point.
>> 
>> Is is best practice? Not even close.
>> 
>> Each device will (should?) generally present a 50Ω termination. In the case
>> of instruments that provide their own ref output which is then looped back
>> in, they may be different, but I don't recall seeing any that said anything
>> other than nothing or 50Ω.
>> 
> 
> I'm confused: I thought most inputs were relatively high impedance.
> 
> The manual for the 5335a specifies its external timebase input as being
> 1000Ω
> (http://www.dennlec.com/images/manuals/hp-5335a-op-manual.pdf). Maybe not
> "high",
> but it's certainly not 50.
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Re: [time-nuts] Distribution divider/amplifier for 10MHz GPSDO

[Bob Bownes]

Will it work? Probably. Up to a point.

Is is best practice? Not even close.

Each device will (should?) generally present a 50Ω termination. In the case
of instruments that provide their own ref output which is then looped back
in, they may be different, but I don't recall seeing any that said anything
other than nothing or 50Ω.

That being said, I've daisy chained a few together to get quick results
without trouble.

Bob


On Mon, Oct 23, 2017 at 1:49 PM, Jeremy Elson  wrote:

> I was about to ask a related question of the list: when do you need a
> distribution amplifier, and when is it sufficient to just have a single
> (linear) run of coax?
>
> I have a GPSDO (Nick Sayer's device) that I want to use to feed a few other
> pieces of equipment in my lab (an HP5335A, John Ackermann's beautiful TICC,
> and a Rigol signal generator). Is it safe to have RG174 coming out of the
> GPSDO, tapping into it with a BNC T-junction that plugs into the back of
> each device that needs the 10mhz input, and then terminating the strand
> with a 50 ohm terminator? (In other words, the way thinnet Ethernet was
> wired back in the day.) As long as the signal goes in a straight line, not
> a "Y" (i.e. no cables attached to the t-junction taps, just a direct input
> into a high-z input) it seems like it should work. Do I need a distribution
> amplifier? Or is that, say, if the signal needs to split off in multiple
> directions and you don't want to fill your lab with a space-filling curve
> of coax?
>
> -Jeremy
>
> On Mon, Oct 23, 2017 at 10:26 AM, Bob kb8tq  wrote:
>
> > Hi
> >
> > The correct answer to any real question like this is “that depends”.
> >
> > For anything that I normally run as test gear, noise outside a very
> narrow
> > bandwidth really
> > does not matter much. The test gear *assumes* (by design) that the
> > reference signal going
> > into the “ref in” jack is not very clean. It does various tricks with
> > filters and PLL’s to “scrub”
> > the input.
> >
> > If we are talking about the reference into one side of a phase noise test
> > set, then
> > the situation is a bit different. The test set is simply going to tell me
> > what the combined
> > noise is on the two inputs. If one is significantly more noisy than the
> > other, that’s pretty
> > much all I will see. In this case, my answer is “don’t use a distributed
> > signal”. Use a
> > stand alone source as your reference and isolate it from the rest of the
> > world.
> >
> > In any case, making a super duper distribution gizmo and feeding it with
> a
> > noisy signal
> > is not going to make the signal any better. Most GPSDO’s have relatively
> > noisy outputs.
> > Some are better than others. None that I have seen on the surplus market
> > are what
> > I would call quiet at the output jack of the GPSDO. They either have an
> > ocean of spurs
> > or a lot of phase noise. Some have both ….
> >
> > Any time you boost a bunch of signals up to high levels, you create
> “crud”
> > running around your
> > lab / shack. One of the most basic questions should always be “do I
> really
> > need this signal?”. Next
> > should be “how can I have a shorter run?”.  I have many pieces of gear
> > that are rarely used.
> > They use odd references. When I need to use them I rig a reference. That
> > gets shut down
> > once the gear goes back to storage. …. no more birdies every 100 KHz ….
> No
> > need for
> > tripple shielded coax ….
> >
> > Simple answer:
> >
> > Square up the 10 MHz (or whatever) by matching it into a 5.5 V powered
> > high speed CMOS
> > gate. The NC7SZ series is one of many families you can use. A NC7SZ125 is
> > not a bad gate
> > to pick. Distribute the square wave to however many output amps as you
> > need. Each one
> > is another of the same gates with the output matched via a 50 ohm to 50
> > ohm lowpass Tee network
> > with a low Q ( < 2). Likely pad down the output a bit to keep it at a
> > rational level.  Build up however
> > many you need for however many frequencies you require. Very normal
> linear
> > regulator chips
> > are fine for the power. Careful bypassing and solid ground planes are
> > always a good idea.
> > Parts cost wise, postage is likely to cost you more than the components.
> > There are …. errr…
> > many thousands …. of multi output amps of this basic  design out there ….
> > they seem to
> > work pretty well.
> >
> > Yes, there are *lots* of possible twists and turns to this. I’m only
> > guessing about the gear you
> > are trying to run and what you are trying to do with it.
> >
> > Bob
> >
> >
> >
> >
> >
> > > On Oct 23, 2017, at 12:45 PM, Tom Van Baak  wrote:
> > >
> > > List -- Don is having email trouble, but here's his posting:
> > >
> > > --
> > >
> > > From: donaldbcol...@gmail.com
> > > Date: Tue, Oct 24, 2017 at 1:38 AM
> > > Subject:   Distribution divider/amplifier for 10MHz GPSDO
> > >
> > > Hello group. I`m intending to distribute, via 50 

Re: [time-nuts] inexpensive, black box, GPS or NTP based TTL time capture?

[Bob Bownes]

A black box was asked for. Who cares what the OS inside is if you never
need to mess with it. A surprising number of things run linux variants.
Pretty much every smart phone is linux or unix...

What is the output format you would like for your timestamp? disk, network
file system, serial all can be made to work.

One could probably build 10-20 for a couple thousand dollars and make
enough to make it worth the trouble, depending on the output format of the
timestamp.

Pi Zero - $10
SD card - $8
GPS - $4
2x16 LCD display - $5
Enclosure - $15 for small box, $20 for ABS rack mount, $35 for aluminum
Hardware, nuts, bolts, screws, etc - $5
Power Supply - $5
Custom Interface card with buffering for TTL signal, other signal input
method, opto isolator, serial port for config & control, rs-232 out for
timestamp, serial and PPS from GPS, connectors, etc - $20-25 built.
Cables, etc - $5
Small rubber duck or GPS puck antenna $5

Ethernet, add $25.

Pi has USB/HDMI, but you can run it headless too.

Total BOM ~$100 (expensive case)
Development - ~week @$75/hr = $3,000 (board design, prototype, code +
documentation)
Manufacturing, packaging, etc ~$50/unit

Shipped cost/unit, 20 units = $150materials, $150 labor = $300.
40 units = $225

Obviously BOM costs go down w volume, but you'd have to hit at least
quantity 50 to get a good break on enclosures and the custom boards.

So the big variable is how many will you need and what are you willing to
pay the developer. $75/hr is more or less going contract rates in my world.
$125-$150 not unheard of.

One off, no labor cost, cheap. Under $40 if you provide your own enclosure,
antenna, etc.


On Wed, Oct 18, 2017 at 3:26 PM, Hal Murray  wrote:

>
> > For under a $100 you could get a Raspberry Pi, a GPS HAT, and connect
> your
> > input to a GPIO pin.  Configure ntpd to log the real PPS and the input as
> > another 'PPS'.
>
> Is there an option to log all individual PPS events?
>
>
> The $100 for a Pi might be significantly low.  It depends on what you have
> in
> your toy box.
>
> Aside from the Pi and GPS HAT, you also need power and a micro SD card.
> For
> black box applications, you probably want a case.  You may need an external
> GPS antenna.
>
> For getting started, you also need:
>   SD card reader/writer
>   keyboard and mouse (Pi has USB)
>   display adapter (Pi is HDMI)
>   display
>
> I have an old KVM switch.  It uses PS2 rather than USB, so I need a PS2 to
> USB adapter.
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
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Re: [time-nuts] inexpensive, black box, GPS or NTP based TTL time capture?

[Bob Bownes]

So, if I hear you right, you want a ttl input to trigger a timestamp,
accurate to ms or µs to a file, correct?

Bob


On Wed, Oct 18, 2017 at 1:33 PM, Rob Seaman  wrote:

> Attila Kinali wrote:
> > On Wed, 18 Oct 2017 08:47:58 -0600
> > Rob Seaman https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts>> wrote:
> >
> > > I’m at the annual planetary sciences meeting (in Provo this year) and
> several
> > > groups have expressed interest in duplicating our setup (details of FO
> > > converters, Schmitt triggers, etc, omitted) in a “cheap black box” to
> quote
> > > one fellow. Lots of people contribute productively to NEO observations,
> > > including amateurs and small teams with little funding. Improving their
> > > timekeeping would help keep rocks from falling on you and your family.
> >
> > What is this black box supposed to do? Just provide a PPS? IRIG-B?
> > Or does it need to have time-stamping capabilities? If so, how many
> > channels?
> >
> > What are your time precision/accuracy requirements?
> >
> > What how cheap is "cheap"? What is the volume?
>
> Thanks for the quick reply. I should have included the subject line in the
> message:
>
> "inexpensive, black box, GPS or NTP based TTL time capture”
>
> Telescope domes are filled with equipment, in particular the camera
> shutter, that can be instrumented to issue a pulse suitable for hardware
> time capture. We use Meinberg IRIG PCIe cards to trap these and read the
> timestamps using their library routines under Linux. “Black box” to the
> person I was talking to meant no IRIG in the dome, no Linux, and no PCIe
> slot, but rather a self-contained unit that syncs to GPS. When last he
> implemented such a feature at another telescope he didn’t even have time
> capture, but rather the device issued a trigger at a specified moment, so
> the timestamp and the shutter opening were inverted. He also seems to
> prefer the timestamps be issued on a serial connection, not via library.
>
> Unlike laboratory instrumentation, a telescope environment needs to be
> both very automated and very forgiving. Money may also be constrained.
> However, telescopes are also often very flexible and I am willing - no,
> eager - to consider completely different arrangements of equipment.
>
> So, reliable timestamping of a TTL input is the ulitmate goal. One channel
> would be sufficient, but multi-channel would not invalidate an option. PPS
> or IRIG-B (DCLS IEEE-1344) are not required, but might form an intermediate
> part of the solution. Reference could be GNSS or possibly NTP.
>
> Precision varies, but milliseconds down to microseconds. Accuracy should
> match the precision, meaning UTC accurate to same. Extra credit for
> multiple timescale support.
>
> Cheap is what I want to know. I see the previous thread on BB-black and
> could imagine a solution using the real time capabilities of that for a few
> hundred bucks, but these are not experimenters, per se. That’s why they
> want a black box. Volume is one to several, but could imagine a bulk order
> if savings were significant. Hundreds of dollars might be the price point.
>
> Thanks!
>
> Rob Seaman
> University of Arizona
>
>
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Re: [time-nuts] Weird GPSDO behavior

[Bob Bownes]

How much jitter is there in the 8am number?

If industrial, I could easily see the first shift coming in and all
starting up at about the same time and shutting things off one by one as
the jobs finish. But I would also expect it to not show up on weekends
and/or holidays, etc. Same applies for the theoretical UPS truck w GPS
jammer. And there could be several minutes of jitter.

If it's very precise, that would be more along the lines of a software
error.

More data! :)





On Fri, Sep 29, 2017 at 9:13 AM, Rob Kimberley 
wrote:

> I'd go with a power surge as it's so regular at 8AM.
> Rob
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Skip
> Withrow
> Sent: 28 September 2017 21:18
> To: time-nuts
> Subject: [time-nuts] Weird GPSDO behavior
>
> Hello Time-Nuts,
>
> I have a NTGS50AA GPSDO (close cousin to the NTBW50AA and Thunderbolt)
> with the OCXO removed and a SRS PRS-10 rubidium oscillator in its place.  I
> have been running Lady Heather 5.0 and have changed the damping, gain, and
> time constant to give me a 20,000 second time constant with a damping of
> .6.  I have attached a Lady Heather screen shot of the weird behavior.  You
> can see that my GPS antenna is in a very none ideal location (window on the
> west side of the building).
>
> Once per day (about 8am) something disturbs the system.  So, the GPSDO
> spends much of its time recovering and never gives me anywhere near the
> performance that this system is capable of.  I would think that it is not
> the PRS-10 as it has no knowledge of time.  I would also think that it is
> not the GPS system or receiver, since the GPS constellation repeats twice
> per day.
>
> Kind of the two things that I am left with are a glitch by the power
> company every morning (there is some large industrial machinery across the
> street (but then I would kind of expect glitches at 8am and 5pm), and
> perhaps Lady Heather doing something funny.  This system has been running
> for quite some time, I have not tried restarting Lady Heather yet.
>
> Anybody seen anything like this, or have any good ideas?
>
> Thanks in advance,
> Skip Withrow  style="border-top: 1px solid #D3D4DE;">
> 
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Re: [time-nuts] Better GPS coming to phones

[Bob Bownes]

So when can I have an app that turns on SA for the answers from my phone? ;)

> On Sep 27, 2017, at 22:38, Bill Hawkins  wrote:
> 
> Sadly, it is not the phone users who will benefit. It is the advertisers
> who use your location to send targeted ads.
> 
> Time marches on.
> 
> Bill Hawkins
> 
> 
> -Original Message-
> From: Mark Sims
> Sent: Wednesday, September 27, 2017 6:54 AM
> 
> Broadcom has released a phone chip that supports L5 signals... claims 30
> cm accuracy.Maybe you will soon be able to use your phone to set
> your GPSDO location better...
> 
> Also the new iphones now support Galileo in addition to GPS and Glonass.
> 
> http://www.theregister.co.uk/2017/09/27/centimetre_accurate_gnss_chipset
> _tested/
> 
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[time-nuts] 5061A behavior

[Bob Bownes]

So I powered up my trusty 5061A a week or two ago and it's been doing
something interesting. Twice now, the CA lamp has gone out, but the alarm
lamp has not lit. Resetting the logic brings it right back, but this seems
like an improper failure mode.

The alarm lamp is fine, so that's not the issue.

Anyone ever seen this before?

Bob
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Re: [time-nuts] Trimble Thunderbolt no longer determines the correct date

[Bob Bownes]

Forgive my naivete, but if this is something as simple as the t'bolt adding
a 10 bit number to a base date, could not the base date be changed in the
PROM? (Presuming one can get to it, etc) Though I suspect that might not be
all that simple of course. And I'm not taking mine apart to look. :)


On Fri, Jul 28, 2017 at 11:36 AM, Dave B via time-nuts 
wrote:

> Interesting.
>
> What about NTPD implementations, when using a TB as the reference time
> source?  Does that handle the week count roll over as well?  If that was
> added, from what version?
>
> I suspect I may have some updating to do!   I use a TB as a frequency
> ref' and local NTP/NTPD server reference.
>
> The local TB here is showing "week 1959" top left of LH's display window
> (Rev 5.01)
>
> Cheers.
>
> Dave G0WBX.
>
> 
> On 28/07/17 08:14, time-nuts-requ...@febo.com wrote:
> >> Well quite an unpleasant surprise. So after the 30th do the TBolts stop
> > Paul,
> >
> > This topic has been covered a number of times over the years. Some
> time-nuts have even run TBolt's under GPS simulators to verify that the 10
> MHz and 1PPS outputs will be fine. So apparently the only effect is that
> the date & time (in binary TSIP messages) are off by 1024 weeks. This
> rollover-related effect is by now a "common" issue with many GPS receivers.
> >
> > The current version of Mark's Lady Heather program has code to detect
> this and fix it so you're good to go for the next 19.6 years.
> >
> > /tvb
>
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[time-nuts] Of pi and ntp and irig

[Bob Bownes]

All the talk about building a pi with a touchscreen and NTP had me
wondering when I went to the basement to pull a cable in a rack if anyone
had spun up the IRIG-B code on a pi before I go and spin my wheels on it.

Anyone?
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Re: [time-nuts] Power connectors continued

[Bob Bownes]

Keep in mind that there are a large variety of power pole connectors. I first 
encountered them in the cables and connectors used to recharge electric 
forklifts. Plenty big and can handle plenty of power.

> On Jun 22, 2017, at 16:06, Chris Albertson  wrote:
> 
> I think they call these "16mm aviation plugs" in the CNC machine tool
> world.  They are common for connecting servo or stepper motors to their
> controllers.
> 
> they have any number of poles from 2 to 6 or more and screw rings that
> secure them.   Usually really good quality even from Chinese eBay vendors.
> But they are really used only for a cable to chassis and only up to a few
> amps.  here is one
> 
> 
> Why so many connecter types?   So you don't cross stuff up.
> 
> Power poles are great for low-tech 12 volt buss systems that don't need any
> kind of engineering and are tolerant of connecting "anything to anything."
> Amateur radios and lead acid batteries are OK.  Not good for high tech
> battery or their chargers or loads.
> 
> Th XT60 or if you need 90  amps, the XT90 is ok because it is gendered and
> you can't accidentally connect two sources.
> 
> The aviation type are perfect for cabling four or six lead motors.
> 
> I would not use 3-pin XLR for anything but audio.  Don't make it easy to
> connect line level audio to a battery.
> 
> A really dumb idea was this guy, I heard this story secondhand.  He used
> A/C extension cords for speaker cables because they work well for that
> purpose, but then someone plugged a speaker into a 120vac well outlet.   I
> assume it made a load 60 Hz tone for a few cycles.Best to follow
> industry conventions because that is what people expect.
> 
> Even though it would work well electrically, no one uses a mini-USB jack
> for Ethernet and for good reason
> 
> 
> 
> On Thu, Jun 22, 2017 at 11:42 AM, Mark Spencer 
> wrote:
>> Sorry if I have caused any un due confusion thru my perhaps incorrect use
> of the terms "cannon" and "XLR."
>> The green connector with 4 separate female contacts is what I perhaps in
> correctly referred to as a "cannon" connector.  The silver connector with 3
> separate female contacts was what I perhaps incorrectly referred to as a
> "XLR" connector.
>> 
>> Both were in use in my lab powering time nuts gear.
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Mark Spencer
>> 
>> m...@alignedsolutions.com
>> 
>> 
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> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Bob Bownes]

These are the ones we use:

AMP part # 206708-1

Standard Circular Connector PLUG 9 POSITION shell size 13



On Thu, Jun 22, 2017 at 12:11 PM, Mark Spencer <m...@alignedsolutions.com>
wrote:

> I believe the "AMP" connectors you are referring to are what I would call
> a "Cannon" connector.   A good choice for that application IMHO.
>
> Mark Spencer
>
> m...@alignedsolutions.com
>
>
> > On Jun 22, 2017, at 6:47 AM, Bob Bownes <bow...@gmail.com> wrote:
> >
> > Right Tool for the Job.
> >
> > I use barrel connectors when I _want_ the cord to come out when the unit
> falls off the shelf rather than dangle by the power cable.
> >
> > Locking Molex, or, far better, locking AMP connections when I want the
> unit to hang by the cord when necessary.
> >
> > We've gone to 9 pin circular locking AMP connectors for rotors on our 2x
> /year ham radio contest set up on the mountain (take a look for W2SZ /
> MGEF). Waterproof (not water tight), sturdy, impossible to misalign. And
> 40' of cable can hang from one for a few minutes if need be.
> >
> >
> >
> >
> >> On Jun 22, 2017, at 09:03, Clint Jay <cjaysh...@gmail.com> wrote:
> >>
> >> Heh, I was thinking just that when I typed it. They're almost inverted,
> the
> >> pegs are on the plug and the slots are on the socket, the ones I've seen
> >> aren't spiral slots, you have to fully engage the plug before you twist.
> >>
> >> I like PowerPoles, I like barrel connections, as with so many things
> it's
> >> all about the application, choose the one that works for you.
> >>
> >>
> >>
> >>> On 22 Jun 2017 1:53 pm, "Bob Bownes" <bow...@gmail.com> wrote:
> >>>
> >>> Locking barrel connectors...
> >>>
> >>> Aren't those called BNCs? ;)
> >>>
> >>> In one of my other lives, I see Power Poles used in a very life
> critical
> >>> application. They are used to connect pads to Automatic External
> >>> Defibrillators. In that application, the two poles (15A, red & white)
> are
> >>> glued together rather than using the roll pin.
> >>>
> >>> Bob
> >>>
> >>>> On Jun 22, 2017, at 08:29, Clint Jay <cjaysh...@gmail.com> wrote:
> >>>>
> >>>> It is possible to get hold of locking barrel connectors, they insert
> as
> >>>> normal and a quarter twist fastens them in place. The plugs and
> sockets
> >>> are
> >
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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Bob Bownes]

Right Tool for the Job. 

I use barrel connectors when I _want_ the cord to come out when the unit falls 
off the shelf rather than dangle by the power cable. 

Locking Molex, or, far better, locking AMP connections when I want the unit to 
hang by the cord when necessary. 

We've gone to 9 pin circular locking AMP connectors for rotors on our 2x /year 
ham radio contest set up on the mountain (take a look for W2SZ / MGEF). 
Waterproof (not water tight), sturdy, impossible to misalign. And 40' of cable 
can hang from one for a few minutes if need be. 




> On Jun 22, 2017, at 09:03, Clint Jay <cjaysh...@gmail.com> wrote:
> 
> Heh, I was thinking just that when I typed it. They're almost inverted, the
> pegs are on the plug and the slots are on the socket, the ones I've seen
> aren't spiral slots, you have to fully engage the plug before you twist.
> 
> I like PowerPoles, I like barrel connections, as with so many things it's
> all about the application, choose the one that works for you.
> 
> 
> 
>> On 22 Jun 2017 1:53 pm, "Bob Bownes" <bow...@gmail.com> wrote:
>> 
>> Locking barrel connectors...
>> 
>> Aren't those called BNCs? ;)
>> 
>> In one of my other lives, I see Power Poles used in a very life critical
>> application. They are used to connect pads to Automatic External
>> Defibrillators. In that application, the two poles (15A, red & white) are
>> glued together rather than using the roll pin.
>> 
>> Bob
>> 
>>> On Jun 22, 2017, at 08:29, Clint Jay <cjaysh...@gmail.com> wrote:
>>> 
>>> It is possible to get hold of locking barrel connectors, they insert as
>>> normal and a quarter twist fastens them in place. The plugs and sockets
>> are
>>> compatible with non locking equivalents too.
>>> 
>>> Of course they're not great for applications that need a decent amount of
>>> current and other disadvantages as noted elsewhere.
>>> 
>>>> On 22 Jun 2017 1:11 pm, "Attila Kinali" <att...@kinali.ch> wrote:
>>>> 
>>>> Moin,
>>>> 
>>>> On Thu, 22 Jun 2017 06:20:27 -0500
>>>> Clay Autery <caut...@montac.com> wrote:
>>>> 
>>>>> TVB for the win!  
>>>>> 
>>>>> Can we please let it go here?
>>>>> Do we REALLY need to have the same PPcon discussion yet again?
>>>> 
>>>> Actually, I read it with interest. I am designing quite a bit of
>>>> electronics. A lot of it is single use, then "throw-away" these
>>>> days so long running times are not that much of an issue.
>>>> But selecting the right power connector is always a problem
>>>> I face. I often choose the 5.5x2.5mm barrel plugs, as they are
>>>> quite common on power supplies, but they are kind of suboptimal
>>>> when it comes to retentiony The Kycon 4-pole plug is slightly
>>>> better, but every and each power supply has a different pinout,
>>>> which means that I either need to design it for a specific power
>>>> supply or add 8 diodes to get the polarity right.
>>>> 
>>>> I pondered a couple of times to use Molex Micro-fit connectors,
>>>> as they are cheap, locking and available in almost any number of
>>>> poles. The current and voltage rating hare high enough for almost
>>>> all needs (but not enough for 240V mains, even if it's rated 300V!).
>>>> And incidentally the crimping tool doesn't cost an arm and a leg.
>>>> But it's not really a connector one wants to use to power a device
>>>> in a proper housing.
>>>> 
>>>> Reading on what other people are using and what advantages/disadvantages
>>>> the different power plugs have is quite interesting for me.
>>>> 
>>>> So, please keep it comming!
>>>> 
>>>>   Attila Kinali
>>>> --
>>>> It is upon moral qualities that a society is ultimately founded. All
>>>> the prosperity and technological sophistication in the world is of no
>>>> use without that foundation.
>>>>-- Miss Matheson, The Diamond Age, Neil Stephenson
>>>> ___
>>>> 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.
>>>> 
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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Bob Bownes]

Locking barrel connectors...

Aren't those called BNCs? ;)

In one of my other lives, I see Power Poles used in a very life critical 
application. They are used to connect pads to Automatic External 
Defibrillators. In that application, the two poles (15A, red & white) are glued 
together rather than using the roll pin. 

Bob

> On Jun 22, 2017, at 08:29, Clint Jay  wrote:
> 
> It is possible to get hold of locking barrel connectors, they insert as
> normal and a quarter twist fastens them in place. The plugs and sockets are
> compatible with non locking equivalents too.
> 
> Of course they're not great for applications that need a decent amount of
> current and other disadvantages as noted elsewhere.
> 
>> On 22 Jun 2017 1:11 pm, "Attila Kinali"  wrote:
>> 
>> Moin,
>> 
>> On Thu, 22 Jun 2017 06:20:27 -0500
>> Clay Autery  wrote:
>> 
>>> TVB for the win!  
>>> 
>>> Can we please let it go here?
>>> Do we REALLY need to have the same PPcon discussion yet again?
>> 
>> Actually, I read it with interest. I am designing quite a bit of
>> electronics. A lot of it is single use, then "throw-away" these
>> days so long running times are not that much of an issue.
>> But selecting the right power connector is always a problem
>> I face. I often choose the 5.5x2.5mm barrel plugs, as they are
>> quite common on power supplies, but they are kind of suboptimal
>> when it comes to retentiony The Kycon 4-pole plug is slightly
>> better, but every and each power supply has a different pinout,
>> which means that I either need to design it for a specific power
>> supply or add 8 diodes to get the polarity right.
>> 
>> I pondered a couple of times to use Molex Micro-fit connectors,
>> as they are cheap, locking and available in almost any number of
>> poles. The current and voltage rating hare high enough for almost
>> all needs (but not enough for 240V mains, even if it's rated 300V!).
>> And incidentally the crimping tool doesn't cost an arm and a leg.
>> But it's not really a connector one wants to use to power a device
>> in a proper housing.
>> 
>> Reading on what other people are using and what advantages/disadvantages
>> the different power plugs have is quite interesting for me.
>> 
>> So, please keep it comming!
>> 
>>Attila Kinali
>> --
>> It is upon moral qualities that a society is ultimately founded. All
>> the prosperity and technological sophistication in the world is of no
>> use without that foundation.
>> -- Miss Matheson, The Diamond Age, Neil Stephenson
>> ___
>> 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.
>> 
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Re: [time-nuts] Looking for info on Trimble 16634-10

[Bob Bownes]

Pretty sure that connector is an off the shelf Amphenol part. If you can't find 
it, however, you can replace it with an off the shelf one that will fit in the 
same hole. (If your lucky, you can even re-use the pins.)

The replacement will run you about $30-40 for the pair, chassis and plug. Check 
Mouser, etc. 

> On May 19, 2017, at 23:21, Bob kb8tq  wrote:
> 
> Hi
> 
> The mating side of that 22 pin connector isn’t going to be cheap. It looks 
> like something out of their 
> government systems group back in the late 90’s. If it is, you may have a hard 
> time getting info on it.
> I’d pop it open and see what’s inside. At least that will give you an idea if 
> it’s 20 years old or 5 years
> old. Knowing the era should help in the search for information. 
> 
> Bob
> 
>> On May 19, 2017, at 10:21 PM, Scott Armstrong  wrote:
>> 
>> Hello all,
>> 
>> I acquired a Trimble 16634-10 receiver. A search of the web has turned up
>> nothing so far.
>> The unit is in a steel box built like a tank. SMA connector for antenna
>> input and a 22 pin circular connector for the I/O and power
>> 
>> Does anyone have any pin out information, specs, etc.?
>> 
>> A picture of the unit can bee seen on ebay at
>> 
>> http://www.ebay.com/itm/TRIMBLE-NAVIGATION-GPS-UNIT-16634-10-/361934484802?nma=true=8bBNGShIPf%252FvJpucfMDlEGXDrwI%253D_cvip=true=nc&_trksid=p2047675.l2557
>> 
>> 
>> Thanks in advance,
>> 
>> Scott AA5AM
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Re: [time-nuts] Machining some aluminum help!

[Bob Bownes]

We also used helicoils in titanium frames of the supercomputer I used to work 
with. Meant we could use relatively standard fasteners without fear of falling. 

On a time nuts related note, I have a u blox GPS-1E that seems to be stuck 
spewing out in ublox format. With no development sw available (that runs on my 
Mac), I'm looking for the correct string to send its way to change it back to 
NMEA. Anyone point me at some docs or know the appropriate string?

Thanks!
Bob

> On May 19, 2017, at 15:51, Lincoln  wrote:
> 
> 
>> 
>> There are a lot of variables involved. Run the screws in and out of the 
>> aluminum a number of times and 
>> the holes will fail first ….There are other gotchas as well.
>> 
>> Bob
>> 
> 
> This is where helicoils come in to play. They are used a lot on the CVD 
> furnaces that I used to make parts for. They are not just for un-buggering a 
> thread. They would be installed form the get go and could be replaced should 
> something gall. 
> 
> Link
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Re: [time-nuts] Looking for a HP-58503 display

[Bob Bownes]

On a (slightly) related note, I have a Futaba DRO on my milling machine.
The VFD display, as you mention, had grown very dark from being left on
constantly. As it was a simple display with 6 7 segment digits, conversion
to LED was actually pretty easy. It took about 4 hours one Sunday
afternoon. There are a couple of indicators on the display as well, but
they are not used on my model, however, I could have replaced them with a
single LED and silhouette easily enough.

The process was pull the display, pull the display drivers, replace the
drivers with some header plugs that pass input to output, send the output
to a display board where they go to a pair of 74AHCxxx buffers (inverting
iirc), which then directly drive a pair of three digit common cathode LED
displays.

Bob
KI2L


On Tue, May 9, 2017 at 3:42 PM, Gregory Beat  wrote:

> Mark -
>
> Option 001 for the HP-5803B GPSDO
> featured a 12-character (alphanumeric) Vacuum Fluorescent Display (VFD).
> It appears to have been a custom VFD for HP / Agilent (Colons used in time
> display).
> http://www.leapsecond.com/museum/hp58503a/097-58503-13-iss-1.pdf
>
> Noritake Itron Corp. (Ise Electronics Corp.) of Japan invented the VFD
> technology in 1967.  Noritake, Newhaven, Futaba, Samsung, and a Chinese
> mfg. are the 5 major mfg.
> Three of these companies have their North American HQ offices here in
> Chicago area.
>
> Futaba in Schaumburg
> http://www.futaba.co.jp/en/display/vfd/lineup.html
>
> Noritake Itron Company in Arlington Heights
> https://www.noritake-elec.com/
>
> Newhaven Display in Elgin
> Company is more of an East Asian importer, but handles custom runs.
> http://www.newhavendisplay.com/vfd-c-586.html
>
> VFD do have a finite life, and darken as they age.  Samsung states 30,000
> hours to reach it 80% level (brightness).  You stated your unit has 83,000
> hours.
> DOUBLE CHECK DC Power and electrolytic capacitors associated with circuit,
> this has been known issue with commercial consumer appliances with VFD.
> The mfg. date on your unit may have been during "bad caps" decade.
>
> greg
> w9gb
> ==
> > I recently got in an HP-58503B GPSDO from a local equipment liquidation
> auction.
> > The unit has 83,000 hours of run time.  I think it was last powered up
> in 2013.
> >
> > The display (VFD) is a bit dim and blotchy.
> > Does anybody have a replacement display that would look better?
> > - Mark
> --
> Sent from iPad Air
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Re: [time-nuts] Line Frequeny Stablity

[Bob Bownes]

In college we had a Vax 11/730 that would freak out and reboot the same time 
every day. Turns out the culprit was the sync pulses put on the AC for 
synchronizing the classroom clocks...But it took DEC a few weeks to find the 
culprit. 

> On Apr 5, 2017, at 17:12, Bob kb8tq  wrote:
> 
> Hi
> 
> Back in high school, one of the radio club members figured out that the 
> “clock adjustment” took place 
> locally between 4:30 and 5:00 PM. Needless to say, pretty much everybody 
> spent the next week listening 
> to WWV and watching the clock’s second hand go out of sync with the beeps. 
> This was back in the  late 1960’s 
> and the idea of a grid was a bit looser than it is today. Indeed it was post 
> 1964 so there *were* grids big 
> enough to take out the whole north east section of the US. Since we were very 
> much in that area the 
> topic of grid sync came up. Nobody ever really had a good answer to that 
> question. That included the 
> guys who ran the local power company. 
> 
> Bob
> 
>> On Apr 5, 2017, at 3:05 PM, Hal Murray  wrote:
>> 
>> 
>> preilley_...@comcast.net said:
>>> When I installed power plants in the 1970's they has a special "clock"  that
>>> showed the cumulative error in terms of clock time.
>> 
>> How big were the grids back then?
>> 
>> What was the typical range of error over a day or month?
>> 
>> 
>>> If the generator ran a little too fast the clock would move forward.As
>>> the operator observed the clock moving away from zero he would reduce the
>>> plant's  power and the clock would move backward toward zero.  ...
>> 
>> Does that operator control a single generator or a whole grid?
>> 
>> Does having a human in the loop help the control loop stability?
>> 
>> 
>> 
>> -- 
>> These are my opinions.  I hate spam.
>> 
>> 
>> 
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Re: [time-nuts] Timelab, GPIB-USB-B in a VM

[Bob Bownes]

Yup, I'm using VBox. Kinda have to on account it $DAY_JOB. ;)

In any case, it appears, in the USB case, to be an Issue with the GPIB-USB-B as 
when I swapped it out with a GPIB-USB-HS, it all comes right up. 

I'm suspicious of the GPIB-ENET, and am wondering if I've been bitten by a No 
Longer Supported by NI issue. Bah. 

In any case, there is a nice 8 hour adev running on an old 10811 that's been on 
the bench for a while. Will swap that one out for one marked 'bad phase noise' 
in the am and see how they match up. 

> On Mar 27, 2017, at 21:20, Bob Stewart <b...@evoria.net> wrote:
> 
> I don't know how they're done in VMWare, but in VirtualBox, you have to setup 
> the USB configuration for the VM before you start it.  You just click the 
> machine, settings, then USB, then add a device, then select from what's 
> available.  Which means you have to have it plugged in and enumerated first.
> 
> Bob 
> 
> 
>  From: Bob Bownes <bow...@gmail.com>
> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> 
> Sent: Monday, March 27, 2017 8:03 PM
> Subject: Re: [time-nuts] Timelab, GPIB-USB-B in a VM
> 
> John,
> 
> Thanks for the reply.
> 
> I'm obviously missing something as I can't see the GPIB-USB-B or the
> ethernet connected GPIB-ENET.
> 
> It's really as simple as going to aquire->HP5371/5372 and the interfaces
> should be in the list, correct?
> 
> Thanks,
> Bob
> 
> 
>> On Mon, Mar 27, 2017 at 6:42 PM, John Miles <j...@miles.io> wrote:
>> 
>> Try running the 32-bit version (timelab.exe) instead of timelab64.exe,
>> even if the VM supports 64-bit execution.  That can sometimes help with
>> compatibility.
>> 
>> -- john, KE5FX
>> Miles Design LLC
>> 
>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
>>> Bownes
>>> Sent: Monday, March 27, 2017 2:49 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: [time-nuts] Timelab, GPIB-USB-B in a VM
>>> 
>>> So I'm trying to run timelab in a windows 7 VM with a GPIB-USB-B
>> interface.
>>> 
>>> Anyone ever tried such a thing?
>>> 
>>> The NI explorer sees the interface but nothing else does.
>>> 
>>> Pointers welcome!
>>> 
>>> Data on a bunch of oscillators as soon as I get it to work...:)
>>> 
>>> Thanks,
>>> Bob
>>> ___
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>> 
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> 
> 
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Re: [time-nuts] Timelab, GPIB-USB-B in a VM

[Bob Bownes]

John,

Thanks for the reply.

I'm obviously missing something as I can't see the GPIB-USB-B or the
ethernet connected GPIB-ENET.

It's really as simple as going to aquire->HP5371/5372 and the interfaces
should be in the list, correct?

Thanks,
Bob


On Mon, Mar 27, 2017 at 6:42 PM, John Miles <j...@miles.io> wrote:

> Try running the 32-bit version (timelab.exe) instead of timelab64.exe,
> even if the VM supports 64-bit execution.  That can sometimes help with
> compatibility.
>
> -- john, KE5FX
> Miles Design LLC
>
> > -Original Message-
> > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
> > Bownes
> > Sent: Monday, March 27, 2017 2:49 PM
> > To: Discussion of precise time and frequency measurement
> > Subject: [time-nuts] Timelab, GPIB-USB-B in a VM
> >
> > So I'm trying to run timelab in a windows 7 VM with a GPIB-USB-B
> interface.
> >
> > Anyone ever tried such a thing?
> >
> > The NI explorer sees the interface but nothing else does.
> >
> > Pointers welcome!
> >
> > Data on a bunch of oscillators as soon as I get it to work...:)
> >
> > Thanks,
> > Bob
> > ___
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> > bin/mailman/listinfo/time-nuts
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[time-nuts] Timelab, GPIB-USB-B in a VM

[Bob Bownes]

So I'm trying to run timelab in a windows 7 VM with a GPIB-USB-B interface.

Anyone ever tried such a thing?

The NI explorer sees the interface but nothing else does.

Pointers welcome!

Data on a bunch of oscillators as soon as I get it to work...:)

Thanks,
Bob
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Re: [time-nuts] Time Dilation tinkering

[Bob Bownes]

It's not getting one past the airport authorities that's the issue. It's 
getting one that's powered up past them. ;)

Written from about 10,000'. :)

> On Mar 22, 2017, at 20:15, Tom Van Baak  wrote:
> 
> Chris Albertson wrote:
>> Why drive up a mountain?
> 
> "Because it's there" ;-)  And because there's a paved road, and it's free, 
> and there's a place to stay overnight, and the mountain doesn't move. Plus a 
> car makes a good portable time lab; you can share the experience with family 
> or students or visiting time nuts; and a number of technical reasons.
> 
> But most importantly: you can remain at altitude as long as you want -- in 
> order to accumulate just enough nanoseconds of time dilation to meet your 
> experiment's S/N goal -- without running into (or much worse, going beyond) 
> the flicker floor of your clocks.
> 
> There are several different ways to measure time dilation with atomic clocks. 
> Some notes here:
> http://leapsecond.com/pages/atomic-tom/
> 
> 
>> Take the clock with you inside the pressurized cabin of a commercial airliner
> 
> Yes, and this has been done many times. The first (1971) and most famous of 
> all traveling clock relativity experiments is:
> https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment
> 
> For vintage hp flying clock articles see:
> https://www.febo.com/pipermail/time-nuts/2013-January/073743.html
> 
> Two modern examples are described here:
> 
> "Time flies"
> http://www.npl.co.uk/news/time-flies
> 
> "Demonstrating Relativity by Flying Atomic Clocks"
> http://www.npl.co.uk/upload/pdf/metromnia_issue18.pdf
> 
> /tvb
> 
> - Original Message - 
> From: Chris Albertson 
> To: Tom Van Baak ; Discussion of precise time and frequency measurement 
> Sent: Tuesday, March 21, 2017 7:12 PM
> Subject: Re: [time-nuts] Time Dilation tinkering
> 
> "flight" there is the word.Why drive up a mountain?   Take the clock with 
> you inside the pressurized cabin of a commercial airliner next time you are 
> on one of those 10 hour trans=pacific flights.   You be taller then any 
> mountain and it is actually cheaper then a weather balloon. 
> 
> Can you get a Rb clock past the TSA x-ray machine.   Maybe if you ask first.  
> There must be a way to hand cary specialized equipment.
> 
> On Tue, Mar 21, 2017 at 7:03 PM, Tom Van Baak  wrote:
> 
> But attached is one of the first plots where I put a SA.32m in a home-brew 
> vacuum chamber and pulled down to a few inches of Hg for a few hours to 
> simulate the low pressure of a flight up to 50 or 90,000 ft. For a high 
> altitude relativity experiment -- where you'd like your clock to remain 
> stable to parts in e-13 and not accumulate too many stray ns -- it's not a 
> good sign when your clock changes by 2e-11 (that's more than 1 ns per minute) 
> just because of ambient pressure changes.
> 
> 
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Re: [time-nuts] Antique precision timing device without electronics

[Bob Bownes]

Don't forget, seawater is the return path...

> On Mar 17, 2017, at 18:04, Hal Murray  wrote:
> 
> 
> e...@scace.org said:
>>   Frequencies around 15 Hz were common on early 20th century cables,
>> depending on the degree of success in compensating for the inherent
>> capacitance on a cable thousands of miles long surrounded by conductive
>> sea water.
> 
> Is the sea water relevant?
> 
> Does enough energy leak through the shield so that it matters?  How well does 
> coax work at low frequencies?
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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Re: [time-nuts] Bye-Bye Crystals

[Bob Bownes]

not to mention +/- a few hundred ppm is not a big deal.

You can always correct for it in software. ;)


On Tue, Mar 14, 2017 at 8:49 AM, jimlux  wrote:

> On 3/14/17 5:04 AM, Bob Camp wrote:
>
>> Hi
>>
>> The cost difference between a complete oscillator package and a simple
>>> crystal is tiny.  The osc is often cheaper if you include board space or
>>> engineering time.
>>>
>>
>> Purchased in volume, the difference it the price of a crystal vs a
>> complete XO
>> is enormous. You will see at least a 10:1 cost savings on the crystal and
>> likely
>> more than that.  Simply attaching a crystal to the internal oscillator
>> inside a
>> chip is nearly zero engineering cost.  If your product is cost sensitive
>> and
>> not super tight tolerance … you go with the crystal.
>>
>>
> And that crystal business (gazillions of inexpensive 16 MHz crystals) is
> very different from making an approximately 12 MHz crystal used in a VCXO
> that will be FMed and multiplied up by 36 to make a 430 MHz transmitter,
> oh, and that matches whatever temperature compensation scheme GE used in
> 1970.
>
>
>
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Re: [time-nuts] TTimelab question

[Bob Bownes]

We have a local metalworking place that will laser cut steel and Al to 3/8". 
For small runs (like 1), they are very competitive to simply buying the 
materials alone. I had them make me 3 1U panels from 3/16" steel with 12 D 
holes to build N patch panels. $15 ea. Powder coated in my color of choice. 
Blanks were about 6 iirc. Well worth not punching all those holes!

Take a look in your search engine of choice. If you can't find one, our guy 
will ship. ;)

> On Feb 22, 2017, at 16:44, Bob Stewart  wrote:
> 
> Hi John,
> 
> I have to agree with you about enclosures.  They make the difference between 
> a DIY unit and a nice commercial unit, but they are very expensive.  The 
> enclosures I use are about $20 each from Mouser.  But the end panels are 
> another $20 each: milled front and back.  So, that's $60 per unit.  One 
> suggestion I might make is to check into what it would cost to make the end 
> panels from circuit board.  At volume, it might be significantly cheaper that 
> $20 per panel.  Learning KICAD well enough to make an end panel isn't that 
> difficult.
> 
> OSHPark has better prices on larger volume orders.  Off the cuff without 
> looking, I think I pay about $19 per mainboard for an order of 10, so that 
> would probably work out to $15 for a pair of PCB end panels.  That's still 
> $35 per enclosure, though.  You'd probably need to order 15 of each to meet 
> their minimums.  There are other suppliers that have better prices, but I 
> have no experience with them or their costs.  It wouldn't be as nice as 
> milled aluminum, but it should work just as well.
> Bob 
> -
> AE6RV.com
> 
> GFS GPSDO list:
> groups.yahoo.com/neo/groups/GFS-GPSDOs/info
> 
>  From: John Ackermann N8UR 
> To: Discussion of precise time and frequency measurement  
> Sent: Wednesday, February 22, 2017 8:13 AM
> Subject: Re: [time-nuts] TTimelab question
> 
> I really like the setup that Mark is describing.  As to TAPR's plans, 
> we've found that enclosures are a challenge -- metalwork is pretty 
> expensive unless you get significant volume, and in our niche market, 
> that's hard to do.
> 
> But I am hoping to find an inexpensive clamshell-type enclosure with 
> flat front and rear panels, and then do up designs (perhaps with Front 
> Panel Express) for those panels.  That can be done at a reasonable cost, 
> and at a minimum we can make design files available so people can order 
> their own panels.
> 
> For my own use, I'm also going to do a couple of 2U rack enclosures -- 
> one to hold two TICCs operating independently, and another for the 
> "megaTICC" -- four units slaved together to make an 8 channel counter, 
> with a Raspberry Pi controller along the line of what Mark described. 
> (In multi-board mode, each TICC outputs on its own USB line, so the 
> RPi's main purpose is to deal with the 8 channels of data from 4 USB 
> connections.)
> 
> I'll make the design files for those enclosures available as well, but 
> it may be a while as my entire lab is now packed up as we are in the 
> final stages of moving from Atlanta back to Dayton.
> 
> Also, in a day or three I'll be announcing a simple project that sprung 
> out of the TICC assembly and testing process that some of you might find 
> useful.  We're still finalizing details on that.
> 
> John
> 
> 
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Re: [time-nuts] purpose of time of day display units

[Bob Bownes]

#5) Everyone likes blinkenlights. 



> On Jan 22, 2017, at 08:55, jimlux  wrote:
> 
>> On 1/21/17 10:31 PM, Ruslan Nabioullin wrote:
>> Hi, looking at pictures of various time metrology equipment setups for
>> best practices and inspiration, I have commonly seen time of day display
>> unit(s) installed in racks containing processing or time transfer
>> equipment, e.g.,
>> http://www.xyht.com/wp-content/uploads/2015/05/Powers_Master_Clock.jpg.
>> All that these units do is merely display the time of day and sometimes
>> the date, typically by means of seven segment LED displays, of the time
>> code inputted to them (typically IRIG-B, I'm guessing).
> 
> There's a few reasons I can think of:
> 1) the display is also a distribution amplifier of some sort - one time 
> source going into rack, distributed to things in the rack (or the next rack)
> 
> 2) as phk commented, it lets you know that your time code isn't broken (i.e. 
> someone got in behind the rack and disconnected the wrong cable)
> 
> 3) It's a crude visual check - your eye/brain is pretty good at catching a 
> change in the pattern of blinky lights.  IN this situation, you'd expect all 
> the displays to change simultaneously.
> 
> 4) the equipment configuration "just growed" from a collection of smaller 
> ones, each with its own display.
> 
> We put displays like this in all of our ground support equipment (GSE) racks 
> when doing spacecraft or subsystem tests, mostly for reason #2 and #4.
> 
> You might have a GSE rack or two in the lab when you're building up the 
> subsystem.  Someone else's subsystem has their rack, also with a timecode 
> display.   When you bring the two subsystems together for integration, you 
> bring the racks with them, and it's not worth it to reconfigure.
> 
> 
> 
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[time-nuts] HP 5372A channel c option 030

[Bob Bownes]

While I had the 5372a apart today to replace the battery, I noticed that there 
is an SMA for channel C on the events board and diagram showing a cable from 
there to the front panel. 

This suggests to me that the upgrade is a cable and a key, jumper, or memory 
setting. 

Anyone ever done the upgrade?

Bob
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Re: [time-nuts] Line Voltage - USA

[Bob Bownes]

> How much trouble do hams have with their insurance companies?


Typically very little if you have a rider to cover it. Costs a few $ a year

Had my basement flood a number of years back and take out a few k worth of 
vintage computer gear. Not a problem. Covered to replacement cost. 

I have a similar rider to cover TE. The biggest problem is they want all the 
serial #'s, which is a constantly changing target of course. 

Bob
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Re: [time-nuts] 5372A A7 CPU board

[Bob Bownes]

I took a lot ok through the service manual, but didn't see the A7 schematic. 

Is it someplace non obvious?

Thanks!

> On Jan 2, 2017, at 23:00, John Allen <j...@pcsupportsolutions.com> wrote:
> 
> Hi Bob - I have a OCR'd service manual with schematics.  There is also one on 
> the KO4BB site
> http://www.ko4bb.com/getsimple/index.php?id=manuals
> 
> I can post mine if that one isn't sufficient.
> 
> Regards, John K1AE, Bolton, MA
> 
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Bownes
> Sent: Monday, January 02, 2017 8:13 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] 5372A A7 CPU board
> 
> 
> I have the CPU board 05372-6007 out of my 5372A this evening to replace the 
> battery. While looking at it, I see jumpers for 64/256K and 512k/2M. 
> 
> I suspect the 64/256 is for the RAM as it is located next to the (non 
> socketed) RAM. 
> 
> Does anyone have a schematic or listing of what all the jumpers are for?
> 
> Thanks!
> Bob
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> 
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
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[time-nuts] 5372A A7 CPU board

[Bob Bownes]

 
I have the CPU board 05372-6007 out of my 5372A this evening to replace the 
battery. While looking at it, I see jumpers for 64/256K and 512k/2M. 

I suspect the 64/256 is for the RAM as it is located next to the (non socketed) 
RAM. 

Does anyone have a schematic or listing of what all the jumpers are for?

Thanks!
Bob
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[time-nuts] HP 4352A/B with different signal generator

[Bob Bownes]

There was a thread about using a different SG with the 4352A/B about seven 
years ago. 

I happened upon the answer today. 

Set the SG type from the LO menu. 

Type 1: 8664A/B
Type 2: 8657B
Type 3: 8648B/C, E8241A, E8244A, E8251A, E8255A
Type 4: User defined. 

To define your own, use the GPIB  "SGCMD" command. Details are in the 4352B 
manual, available on exodus.poly.edu. 

Bob, who knows how he's spending the time waiting for the leap second...


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Re: [time-nuts] DIY VNA design [VNA-Nuts?]

[Bob Bownes]

Just finished creating it at groups.io



*https://groups.io/g/svna *
and sign up. :)


On Mon, Aug 22, 2016 at 12:38 PM, Tom Miller 
wrote:

> Maybe do it on Mewe.com?
>
> - Original Message - From: "Oz-in-DFW" 
> To: 
> Sent: Monday, August 22, 2016 11:53 AM
> Subject: Re: [time-nuts] DIY VNA design [VNA-Nuts?]
>
>
>
> So is it time for VNA-Nuts?  I can probably host it.
>>
>> --
>> mailto:o...@ozindfw.net
>> Oz
>> POB 93167
>> Southlake, TX 76092 (Near DFW Airport)
>>
>>
>>
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>
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Re: [time-nuts] Working with SMT parts.

[Bob Bownes]

I've got a great boom Zeiss microscope bought at an estate sale. Right
Place, Right Time.

Before that, I generally used a video camera with some extension tubes, a
USB video capture dongle, and a spare monitor I keep on the workbench. The
monitor and camera are connected with extension cables to the computer
across the room. (ok, 180degree chair swivel way :) )
Getting the lighting right is key. Light ring is good or light close to on
axis helps.

Bob


On Thu, Aug 11, 2016 at 5:06 PM, Graham / KE9H 
wrote:

> The best type of stereo microscope to use for SMT assembly is referred to
> as an "Inspection Microscope."
> Magnification greater than 10 is not needed or desirable for normal
> assembly.
> Something in the range of 5 to 10 works well.
> A wide field of view and a good light source are desirable.
>
> Just as Brooke says, my "zoom" always stays on the lowest setting. (Same as
> his, 0.7 times 10x = 7)
>
> --- Graham
>
> ==
>
> On Thu, Aug 11, 2016 at 1:57 PM, Brooke Clarke  wrote:
>
> > Hi Bob:
> >
> > I don't think it's so much the stereo microscope as the related
> > equipment.  I have a Bausch & Lomb StereoZoom 4  and the dial is always
> at
> > the lowest setting (0.7dial * 10X objective = 7 power).
> > For another reason I got a Nikon SMZ-U microscope and discovered that
> it's
> > so tall that it can not be used for SMT work.
> > http://www.prc68.com/I/NikonSMZ-U.html
> > So an important parameter is is length from the eyepiece to the
> > objective.  If that get to be long then you can not easily use it.
> >
> > Using an arm type support is very desirable.  These have a heavy metal
> > base with an horizontal arm.  You can swing the arm over whatever you're
> > working one and easily move the scope up or down as needed.
> > This all done while in a standard chair on a work bench/table.
> >
> > Although an old fashioned illuminator will work, see top photo:
> > http://www.prc68.com/I/SMT.shtml#Mag
> > A ring light is much more convenient (scroll down a little).
> >
> > Also the soldering iron tip to grip distance should be as short as you
> can
> > get.  (1.5" = burned fingers, 0.5" should be better)
> >
> > --
> > Have Fun,
> >
> > Brooke Clarke
> > http://www.PRC68.com
> > http://www.end2partygovernment.com/2012Issues.html
> > The lesser of evils is still evil.
> >
> >  Original Message 
> >
> >> What are the important parameters regarding purchase of a stereo
> >> microscope?  I see some on ebay for around $50; are those good?
> >> Bob
> >>
> >>  On Thursday, August 11, 2016 10:00 AM, Didier Juges <
> >> shali...@gmail.com> wrote:
> >>
> >>   I concur. I have been using ExpressPCB extensively over the last 2
> years
> >> with great satisfaction now that it is possible to get Gerber files from
> >> them.
> >> I typically use the mini board pro service (3 bare boards, 2 sided with
> >> solder mask and silk screen) for prototypes and then buy the Gerbers to
> >> have production quantities done overseas.
> >> The boards are of high quality and the service is very fast at a very
> >> reasonable price.
> >> The only gotcha with regard to Gerber files is that you can only buy
> >> Gerbers for boards that you have actually bought from them, so the
> process
> >> is to buy the prototypes, then if you are happy with those, buy the
> >> Gerbers
> >> for that design.
> >>
> >> Didier KO4BB
> >>
> >> On Tue, Aug 9, 2016 at 3:06 PM, Brooke Clarke 
> wrote:
> >>
> >> Hi:
> >>>
> >>> I've had good luck using any of the the ExpressPCB services that
> include
> >>> solder mask with surface mount parts where the pitch is 0.05" (half
> >>> normal
> >>> DIP) and hand soldering (requires stereo microscope).
> >>> http://www.prc68.com/I/BTSG.shtml (battery top signal generator)
> >>> http://www.prc68.com/I/Images/ICS525v1o.jpg
> >>>
> >>> http://www.prc68.com/I/SMT.shtml 
> >>>
> >>> --
> >>> Have Fun,
> >>>
> >>> Brooke Clarke
> >>> http://www.PRC68.com
> >>> http://www.end2partygovernment.com/2012Issues.html
> >>> The lesser of evils is still evil.
> >>>
> >>>
> >>> ___
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> >>> and follow the instructions there.
> >>>
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[time-nuts] HP 4352A

[Bob Bownes]

If anyone has an interest, there is at least one HP 4352A VCO/PLL analyzer
left on ebay. $200 OBO.

http://www.ebay.com/itm/HP-Agilent-4352A-VCO-PPL-Signal-Analyzer-Generator-Module-10MHz-3GHz-RF-4352S-/131847308679?hash=item1eb2b64587:g:95cAAOSwZJlXMrpQ

The one I bought for $130 was missing the detector and power splitter.
Replacing the splitter with a home rolled one and the detector with a
similar, though far less expensive part has returned it to the land of the
functioning.

Next step, characterize some of the 10811's I have around here. ;)

No financial interest except helping out a fellow time nut as those before
have helped me.
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Re: [time-nuts] Spectrum Analyzer Specifications

[Bob Bownes]

> Yes, good spec
> ​t​
> rum analyzers usually costs more than 2000 USD even as used. Also, a "high
> end" used 2000 USD spec
> ​t​
> rum analyzer can be much better than brand new "entry level" 1 USD spec
> ​t​
> rum
> ​analyzer. And if you need any kind of vectored signal analysis,
> demodulation capability of modern communications etc. then the price will
> be very high.
>

​You would be surprised. I've been quite cheap and patient and have put
together a quite capable 22GHz HP 7 MMS series SA for under $1KUS. If
you are impatient, it can be done for under $2KUS​. That gets you down to
10Hz RBW, color display, all digital. Not small, but very capable and
expandable. Another $1k (if patient, ~$2.2k if not) will add VNA
capabilities to 40GHz and all the capabilities we talked about using the
Microwave Transition Analyzer + the 70340 1-20GHz signal generator. All
with GPIB control.

Other options also exist. My 8565 SA was less than $1K when I bought it. It
will get a RBW down to about 1KHz. up to 22G without external mixers.
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Re: [time-nuts] Spectrum Analyzer Specifications

[Bob Bownes]

Don't really need anyone who can order up bare boards in bulk anymore. Many
of the board houses will make them on demand for single customers. They fit
them into empty spaces in larger board orders.

I'd love one if someone is willing to draw it up. I'll even put together a
Mouser BOM that can be shared if N8UR will layout the board. :)

Bob
KI2L


On Thu, Mar 24, 2016 at 1:31 PM, John Ackermann N8UR  wrote:

> I'd be willing to assist with board layout if someone wanted to make this
> into a real project (e.g., fully developed schematic).  TAPR might be
> talked into supplying at least bare boards; we'd have to get a sense of
> demand before committing to a full kit or assembled unit.
>
> John
> 
>
> On 3/24/2016 9:04 AM, jimlux wrote:
>
>> More like $40 in parts, without a board, etc.
>> The RPD-1 is $20.70
>> LT1678/LT1679 is a nice low noise opamp that does rail to rail and is
>> about $5
>> etc
>>
>>
>>
>> On 3/24/16 4:42 AM, Bob Camp wrote:
>>
>>> Hi
>>>
>>> Pretty simple:
>>>
>>> Double balanced mixer, RPD-1 is one option, there are others.
>>>
>>> Fairly simple L/C lowpass between the mixer and an op-amp.
>>>
>>> 20 db positive (non-inverting) op-amp amplifier string after the mixer
>>>
>>> Output of the string goes to the sound card. Use a good (dual / quad)
>>> audio op amp
>>>
>>> Quadrature amp picks off the output of the first op amp stage, switch
>>> and resistors to set gain, pot to set op point.
>>>
>>> 
>>>
>>> So what you have is an old style quadrature phase noise amp and “PLL”.
>>> More or less a very junior version
>>> of the 3048 test box. Like any setup of this sort, you check two
>>> similar oscillators. They run in quadrature and
>>> you do a few “measure this with switch in position A” sort of things
>>> to set things up each time.
>>>
>>> Nothing exotic.
>>>
>>> Bob
>>>
>>>
>
 Any documentation on this $40 phase noise test set?

 Rick N6RK

>>>
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[time-nuts] The importance of getting time right

[Bob Bownes]

Interesting article over on Hackaday this morning mentioning a missile
defence system with time drift and the rather tragic consequences.

http://hackaday.com/2015/10/22/an-improvement-to-floating-point-numbers/#more-174711
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Re: [time-nuts] How did they distribute time in the old days?

[Bob Bownes]

Precise time (and time zones) and the relationship with the telegraph were
a side effect of the railroads. You need to keep time (and keep on time) in
order to avoid collisions on single tracked main lines.

On Wed, Oct 14, 2015 at 12:42 PM, Nick Sayer via time-nuts <
time-nuts@febo.com> wrote:

>
> > On Oct 14, 2015, at 4:42 AM, billriches  wrote:
> >
> > Not milisecond time distribution but time related!
> >
> > In the early half of the 1900s Western Union was in the time business.
> They
> > would rent businesses such as banks, office buildings, etc  clocks for a
> few
> > dollars a month.  These were pendulum wall clocks that had 2 #6 dry cell
> > batteries inside that would wind them every hour or so. The clocks were
> > connected to the WU telegraph line and for a minute before and after  the
> > top of the hour all traffic on the circuit would stop.  Exactly at the
> top
> > of the hour they would push a pulse of 50 ? volts or so over the line
> and it
> > would reset the clock to the top of the hour.
>
> The WU standard time service goes back further than the turn of the 20th
> century. It started in 1870.
>
> I’ve always wanted to get my hands on one of those clocks and come up with
> a circuit to recreate the synchronization signal for it, probably with a
> Raspberry Pi running ntpd and a big ol’ MOSFET. The problem is that at this
> point, those clocks are quite expensive once they’re reconditioned.
>
> My understanding (perhaps incorrect) was that the sync pulse was once
> daily and, as you said, would cause the hands to “snap” to 12. The trailing
> edge of the pulse was synchronized and would release the clock to operate
> normally.
>
> That they had something as accurate and widespread as it was so early is
> astonishing.
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Re: [time-nuts] Iridium source?

[Bob Bownes]

JT,

You say GPS isn't available 'often'. Can you define 'often'? As in not at
some locations, or as in GPS signal is only available now and then
temporally?

If the latter, any GPS timing unit with decent holdover should solve the
issue. If the former, well, you've gotten some replies on that.

Failing that, what are your drift tolerances? If you can manually set the
time, or get it 'close' with ntp & friends, a rubidium standard may jitter
a bit, but is pretty stable long term, even if you loose the NTP feed.
Cesium might drift a bit more...

iii

btw: Welcome to time-nuts. These folks are our kinda crazy.

On Mon, Oct 5, 2015 at 4:24 PM, John Todd  wrote:

>
> I’m working on a project that needs a good clocking source deep inside of
> noisy environments (data centers and the like.)  This can’t be
> network-based - it needs to be independent of the systems surrounding it,
> and GPS/GPS-like systems will often be unreachable.  I’ve read up a bit on
> Iridium - it appears that there is some mention of Boeing saying (see slide
> three in below link) that the Iridium LEO network can be used not just as a
> GPS assist, but as an actual timing source.  Their frequencies on the
> timing side seem to penetrate buildings better.  Before you say “Iridium
> doesn’t work indoors!”, this may not be the case with their timing signals.
>
> Has anyone actually used this method for obtaining high-precision time?
> If so, is it possible to do with something smaller/cheaper than the full
> Iridium chipset?  I think the Iridium Core 9523 is something like $1300,
> which puts it outside of consideration for the large deployment we’re
> looking at doing, and we don’t need the voice/data TX or RX components.
>
>
> https://transition.fcc.gov/bureaus/pshs/docs/summits/911%20Location%20Acuracy/Barry_Martin.pdf
>
> Apologies if this is not on-topic here or if there are obvious data that
> I’m missing - I’m a bit new to this niche of the world.  I can’t find any
> mention of this topic past 2012, and it’s sparse even at that.
>
> JT
>
> ---
> John Todd - Senior Technologist - jt...@pch.net - +1-415-831-3123
>
>
>
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Re: [time-nuts] The low budget UT+ newbie time-nut project: FrequencyReference

[Bob Bownes]

Bob,

I'm sure much more qualified nuts will chime in, but a few thoughts of mine.

Over the years, I've collected enough GPS antennas from hamfests, online
vendors and who-knows-where, all for prices from free to tens of dollars.
Most of them came with anywhere from 3' to 10+meters of cable. Most of
those cables have been terminated in SMA connectors. Not sure how long you
think your cable run will be (mine is  15', skylight to workbench) but I'd
stay away from RG6 just as a matter of practice. The antennas are generally
amplified, but still...

MCX to SMA pigtails are cheap and plentiful. Once you are SMA, everything
else is easy.

To me, division is far better than trying to modify the UT+.

Welcome to the asylum. The inmates all have good ideas!

On Tue, May 5, 2015 at 7:35 PM, Tom Van Baak t...@leapsecond.com wrote:

  For reasons unknown to me, the body of the message was missing on the
 first attempt.

 Hi Bob,

 While we debug your mail problem, here is your post.

 /tvb

 - Original Message -
 From: Bob Fleming
 To: time-nuts@febo.com
 Sent: Tuesday, May 05, 2015 3:36 PM
 Subject: The low budget UT+ newbie time-nut project: Frequency Reference


 For reasons unknown to me, the body of the message was missing on the
 first attempt.

 The low budget UT+ newbie time-nut project: Frequency Reference
 Thanks to Bob Stewart’s generous offer I am now in possession of the heart
 of my first time-nut project.

   My first stage plan is to make something for screwdriver disciplining
 the 10Mhz reference on my frequency counter for work with ham radio. Bought
 on ebay for a ridiculous low bid my Fluke 1953A -20 is synced to WWV as
 well as propagation will allow. It was fading in and out over two minutes
 at one point and that is good enough for ham radio but just good enough is
 not what I desire and it took the better part of three days spare time
 fooling with it to get it that close. (fail)
I have seen a reference to changing the 1PPS output of the UT+ to
 100PPS but if that is not applicable to my UT+ I will divide the 10Mhz by
 100. In either case my scope will be triggered with the UT+ to compare
 signals as discussed here a few weeks ago.

First thing I noticed about the UT+ is that the power/control 10 pin
 connector headder on the UT+ looks just like internal USB headers on a
 computer motherboard. In fact, a pair of 5 pin of USB header plugs fit
 perfectly.
Second there is the antenna connector, the OCX. Apparently an MCX is
 required and I have none.
 Then there is wire selection for the antenna. Before I can buy an MCX
 connector I better decide on the wire. I have plenty of RG6 quad shield,
 enough LMR-400 that I was saving for another project and several boxes of
 radio shack RG8 that I can’t find any use for. The rat shack RG8 is pretty
 much hopeless but I haven’t recycled it yet. LMR-400 is too stiff to plug
 directly in the tiny OCX without a pigtail of much more flexible wire and
 extra connectors.
 Input impedance of the UT+ is 50 ohms but I am tempted to use the RG6
 because my 20’ run will only lose about 2 DB not including impedance
 mismatch on both ends. My limited experience with over 1GHz is that any
 connector will have losses so I suspect that using 75 ohm RG6 coax won’t be
 much worse than the LMR-400 with extra connectors, adapter and a pigtail.
 Critique of my plans and/or guidance will be greatly appreciated.
 I guess about a dozen of us will be building newbie time nut projects with
 these.
 Thanks,
 Bob Fleming N5TX

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Re: [time-nuts] Beaglebone NTP server

[Bob Bownes]

If there is always a system running, why go with the bbb? I use the file server 
in the basement fed with 1pps to the non USB serial port from a TBolt in my 
office. 

You do have a file server in the basement don't you? :)

I suppose it would be an interesting experiment to feed an NTP server with 
several PPS signals (either simultaneous or offset) to see how it handles it. 
Or to set up an NTP chorus fed from multiple PPS sources or even a single PPS 
source to see how they average out. Maybe over the holidays. I really should 
finish up running the coax for a shared GPS antenna to the basement.

Bob

PS: As to the buy a second BBB/RPi question, I've taken to buying what I think 
will be key spare parts for projects and stocking them. Each project gets a 
shoebox sized storage bin on the shelves in the basement. One part of the 
shelves is completed projects, the other is in process. It has the added side 
benefit of telling me when I have too many unfinished projects. :)




 On Dec 11, 2014, at 11:45, Tom Holmes thol...@woh.rr.com wrote:
 
 Brian... 
 
 Look, I used to leave WWV running all the time on a receiver. That
 background D D D was very reassuring as I moved through the
 house watching the sweep second hands ticking in time with WWV.
 
 Based on personal experience, this strongly suggests that you weren't married 
 at the time :-).
 
 Tom Holmes, N8ZM
 
 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Brian Lloyd
 Sent: Thursday, December 11, 2014 11:21 AM
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] Beaglebone NTP server
 
 On Thu, Dec 11, 2014 at 10:03 AM, Paul tic-...@bodosom.net wrote:
 
 On Thu, Dec 11, 2014 at 10:27 AM, Dan Drown dan-timen...@drown.org
 wrote:
 
 Is this better or worse than other NTP server platforms?  I haven't
 tested
 them, so I have no idea.
 
 
 Tharp says his appliance
 
 can sustain thousands of queries per second. Even under high throughput
 timekeeping operations are never disrupted or perturbed.
 
 But enough of that.
 
 From the time-nut perspective what's the interest in high resolution NTP?
 I mean beyond the can I do this? appeal.
 
 We are all time nuts to one degree or another or we wouldn't be here. I
 personally want all the clocks in my house, including all the computers (I
 have about 10 running at any given moment here), to have time resolution
 better than my ability to perceive errors. (To my eye that is about 100ms
 for clocks with a sweep second hand.) and in the 1ms-or-better range for
 the computers. I want to know that, when two things get time-stamped on
 different machines, I can tell which happened first from the point of view
 of a DBMS dealing with concurrency issues.
 
 So a stratum 1 server in my house that is independent of my external
 internet connectivity seems desirable.
 
 Look, I used to leave WWV running all the time on a receiver. That
 background D D D was very reassuring as I moved through the
 house watching the sweep second hands ticking in time with WWV. Time to
 move forward in true time-nut fashion.
 
 -- 
 Brian Lloyd
 Lloyd Aviation
 706 Flightline Drive
 Spring Branch, TX 78070
 br...@lloyd.aero
 +1.210.802-8FLY (1.210.802-8359)
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Re: [time-nuts] Divide by five

[Bob Bownes]

I'm surprised no one has suggested 74F161 or other F series. Power hungry, but 
rated to in excess of 100mhz, some vendors as high as 120mhz, at ordinary 
temps. I will have to look, but I might have a tube or two of them in the 
basement. I know I have most of the other 74F.

 On Nov 7, 2014, at 23:20, Said Jackson via time-nuts time-nuts@febo.com 
 wrote:
 
 Joe,
 
 This puppy can go to 166MHz over temp and has standard 100 mil pin spacing if 
 you put it into a socket: ATF16V8C
 
 I have not used PALs since 1992 but I used to be extremely fond of the 16R8 
 and 22V10 types back then.
 
 This is a 16V8 that will do your divider in no time:
 
 http://www.digikey.com/product-detail/en/ATF16V8C-5JX/ATF16V8C-5JX-ND/1027054
 
 Best of all its available and only ~$3..
 
 Said
 
 Sent From iPhone
 
 On Nov 7, 2014, at 19:37, Joseph Gray jg...@zianet.com wrote:
 
 Looks like I can get the 74AC161 in DIP from Mouser. Thanks to everyone for
 the suggestions. I still like DIP for prototyping on breadboards.
 
 Joe Gray
 W5JG
 
 
 On Fri, Nov 7, 2014 at 4:45 PM, Alex Pummer a...@pcscons.com wrote:
 
 
 
 check if you could get a 74AC161, which could be connected  to divide by 5
 at 125 MHz see here http://ecee.colorado.edu/~mcleod/pdfs/IADE/references/
 74AC161.pdf to be sure to work at 125MHz run with 5,5 to 6V...
 
 73
 Alex
 
 
 
 On 11/7/2014 1:12 PM, Joseph Gray wrote:
 
 I need to divide a 125 Mhz clock by five. I have looked on Mouser and
 every
 chip I find is either obsolete or in SMT. Can anyone recommend a chip that
 is fast enough and comes in DIP?
 
 Joe Gray
 W5JG
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Re: [time-nuts] NPR Story I heard this morning

[Bob Bownes]

You people are evil. Now you have me wondering where I can get a microgram
level accurate scale. Simply tracking the weight of a 'constant' (anyone
got a silicon sphere with exactly 1 mole of Si atoms in it? :)) over time
would be an interesting experiment.


As a geologist, I also have to say, that while we know the geoid to ~1cm,
it is ~1cm at the time it was measured, which is constantly changing. The
obvious tidal effects, as well as internal heating effects (and I suspect
external heating effects), continental drift (both long term events and
short term events like earthquakes), currents in the molten layers,
probably magnetic effects all are going to contribute to geoid uncertainty.

I really do need to spin the seismograph back up.



On Tue, Nov 4, 2014 at 2:04 PM, Peter Monta pmo...@gmail.com wrote:

 Hi Tom,



  Based on mass and radius, a clock here on Earth ticks about 6.969e-10
  slower than it would at infinity. The correction drops roughly as 1/R
 below
  sea level and 1/R² above sea level. For practical and historical reasons
 we
  define the SI second at sea level.
 

 Yes, the change in clock rate at sea level is about 1e-18 per centimeter,
 and the geoid is known only to about 1 centimeter uncertainty at best.


  The non-local gravity perturbations you speak of are 2nd or 3rd order and
  so you probably don't need to worry about them. Then again, if you want
 to
  get picky, it's easy to compute how much the earth recoils when you stand
  up vs. sit down. So it's best to avoid the notion of arbitrary
 precision;
  that's for mathematicians. For normal people, including scientists, we
 know
  that precision and accuracy have practical limits.
 

 Let me rephrase what I'm after.  The geoidal uncertainty sets a hard limit
 on clock comparison performance on the Earth's surface (for widely-spaced
 clocks).  At some point, as Chris Albertson noted, the clocks will measure
 the potential and not the other way around.  (It should be possible to
 express this geoidal uncertainty as an Allan variance and include it in
 graphs with the legend Earth surface performance limit.)

 What I'm curious about is this:  what are the limits on clocks in more
 benign environments?  How predictable is the potential in LEO, GEO,
 Earth-Sun L2, solar orbit at 1.5 AU, solar orbit at 100 AU, etc.?  I
 imagine the latter few are probably very, very good, because the tidal
 terms get extremely small, but how good?

 Suppose a clock dropped into our laps with 1e-21 performance, just to pick
 a number.  Where would we put it to fully realize its quality (and permit
 comparisons with its friends)?  And is the current IAU framework adequate
 to define things at this level (or any other arbitrarily-picked level)?
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Re: [time-nuts] NPR Story I heard this morning

[Bob Bownes]

But won't the doppler effect change as the Cs atoms fall down the gravity
well? :)


On Tue, Nov 4, 2014 at 3:14 PM, Attila Kinali att...@kinali.ch wrote:

 On Mon, 3 Nov 2014 11:54:41 -0800
 Peter Monta pmo...@gmail.com wrote:

  Sorry if this is a bit off-topic.  I'd like a simple, clear explanation
 for
  the layman that drills down on exactly how the current definitional
 scheme
  can be realized to arbitrary precision.  For example, assume that we must
  go off-earth at some point to get a better timescale.  How fuzzy is the
  solar potential (soloid)?

 It will be done as usual: As soon as they can reliably measure an
 systematic
 effect that is impossible to cancel out, they will redefine or ammend the
 definition of the second to account for this issue.

 And going by the presentations given at EFTF this year, there is quite
 some interest in precision gravity measurements in the time/frequency
 community. And yes, they use the same basic phyiscs as their atomic clocks
 :-)
 (one apporach is to let Cs atoms fall down a tube and measure their
 acceleration using doppler shift of the hyperfine transitions line)

 Attila Kinali

 --
 I pity people who can't find laughter or at least some bit of amusement in
 the little doings of the day. I believe I could find something ridiculous
 even in the saddest moment, if necessary. It has nothing to do with being
 superficial. It's a matter of joy in life.
 -- Sophie Scholl
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Re: [time-nuts] NPR Story I heard this morning

[Bob Bownes]

I'd be happy to volunteer my 5061 for such an experiment! Located in Troy,
N.Y., I can get it down to about 15' ASL, possibly as low as 12' if I go to
the basement in a downtown building. The river is at 13' ASL iirc.


Bob


On Mon, Nov 3, 2014 at 4:53 PM, Tom Van Baak t...@leapsecond.com wrote:

 David,

 Let's talk. It is not impossible that I could drive my clocks to the East
 Coast for a Mt. Washington experiment.

 /tvb

 - Original Message -
 From: David McGaw n1...@dartmouth.edu
 To: Discussion of precise time and frequency measurement 
 time-nuts@febo.com
 Sent: Monday, November 03, 2014 1:07 PM
 Subject: Re: [time-nuts] NPR Story I heard this morning


  The highest accessible peak in the Adirondacks I think would be
  Whiteface at 4,867 ft, though that would be by ski lift and not all the
  way to the top.  The highest point accessible by car in the Northeast
  would be Mt. Washington here in New Hampshire at 6288 ft.  Hmm...
 
  David

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[time-nuts] Datachron 3070

[Bob Bownes]

Has anyone got a manual for one of these by chance? 

I'd like to feed in an external oscillator but I'd like to know the frequency 
and amplitude before I go plugging it in at random.

Thanks!
Bob
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[time-nuts] 5061A SN1816A01444 lives again

[Bob Bownes]

Yes, Virginia, there are still a few bargains to be had in the world.

After hacking together a power cord, letting it warm up for an hour or so,
and going through the long power off procedure from the manual, the latest
addition to my test equipment collection came to life.

It arrived the other day in a large, well packed box, foamed in place,
marked 'FRAGILE' and 'HEAVY', I was pretty excited to get it down into the
lab and get it powered up. Following the directions in the manual, I let it
warm up, did the proper adjustments, clicked START, counted to 30, hit
'Reset', and was rewarded with a bright green Continuous Operation lamp.

FYI, I paid a grand sum of $250 plus $70 for Fed-Ex shipping for a pretty
nice Cc standard. This is the 5061 I've been waiting for. Well, I would
like the optional LED clock, but I'll live. :)

It now goes into the collection along with the Rubidium standard and the HP
3801 GPSDO.
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[time-nuts] Hp 5061a power cord

[Bob Bownes]

Anyone know where I might find a power cord for a 5061a? Failing that, the pi 
out of the connector?

Thanks!
Bob
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Re: [time-nuts] Oscilloquartz 3210 Cesium Standard

[Bob Bownes]

Is there a similar 'bring it back to life' procedure for the 5061A?


On Thu, Aug 28, 2014 at 12:32 PM, Magnus Danielson 
mag...@rubidium.dyndns.org wrote:

 Chris,

 Do you have a GPS clock?

 First turn the operational mode setting from off to second step (ocxo +
 ion pump) and let it stay there for a day or so.

 Then, as the oven have stabilized, switch it over to third step, the open
 loop mode, and tune the OCXO up against a GPS reference so that it is very
 near 5 MHz. You use the calibration whole on the front of the clock for
 that.

 Then, you turn the operation mode switch to the fourth and last step, the
 closed loop step, and see if it locks up. Let it just sit there and lock
 up, as it takes some time.

 It's quite common that OCXOs have drifted outside the capture range of the
 analogue loop, so loosing lock and not being able to attain it again is a
 typical response.

 Cheers,
 Magnus


 On 08/28/2014 04:33 PM, Chris wrote:

 On 08/28/14 05:03, Javier Herrero wrote:

 Hello,

 Here is the manual I've. I have also some other documentations, and some
 Oscilloquartz software for the OSA-5585, but I don't know if they are
 very useful.

 Regards,

 Javier


 Hi Javier,

 Thanks for that and for the other replies. The 3210 looks like quite an
 early design, with no sign of microprocessors at all. There's a 8 slot
 card cage with a load of discrete analog circuitry, 741 op amps etc and
 a couple of boards full of 14 / 16 pin ssi cmos / ttl devices, which I
 guess would be the synthesiser logic and perhaps a state machine style
 startup sequencer. Apart from that, the rest is power supply related and
 what looks like an alarm board with optoisolator discete outputs to a 25
 way D connector. The step recovery diode (?) multiplier into the
 microwave cavity is a really neat gold plated assembly with what looks
 like a 50r termination (setup tap for spectrum analyser ?) and an
 adjustment trimmer, but am not touching that or the many trimpots on the
 boards or any adjustments until I have more info. The tube is from FTS,
 part number / model 7101.

 It seems strange that the 2nd harmonic, meter #9, is zero, since even
 with a tube approaching eol, one would expect at least some indication,
 which is why I think there may be an electronic fault. Perhaps the hv
 power supply module feeding the electron multiplier. Will try to measure
 that, but the area around the tube is really heavily rivetted and
 screwed down in all directions. Looks like a lot of the left hand side
 of the case will need to be disassembled just to get at the tube
 connections. It also had the battery backup option, with 4 sets of 3 x
 cyclon type cells, but with a date code of 1984, are seriously dead and
 have been removed.

 This time nuts things seems to be a growing interest and wonder if there
 is a cure ? :-). Recently bought a 1970's era Tracor 304D rubidium
 standard. Again, no lock, but a very well engineered and screwed
 together piece of kit and should be fixable. Collection now includes the
 Z3816, from Ebay US around 7 years ago, a Z3815 currently being
 repackaged, an HP103 with open circuit oven heater elements and the
 3210...

 Regards,

 Chris



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Re: [time-nuts] Tektronix TM500 extender cable kit

[Bob Bownes]

I might be interested. Have you thought about making extensions for the smaller 
connector used to distribute GPIB in the 5000 series?

 On Aug 4, 2014, at 0:26, Mark Sims hol...@hotmail.com wrote:
 
 I just finished laying out a small circuit board for building an extender 
 cable for the Tek TM500 series mainfames / modules.  Prototypes are off being 
 fab'd at OSHPARK.  Should be here in a couple of weeks.  It uses two 39/40 
 pin ribbon cables (all the power pins use two wires)... e.g.  IDE/PATA disk 
 drive cables.
 I know LOTs of us have and use these venerable old workhorse machines.  They 
 are well documented and easily maintained (particularly if you have extender 
 cables).  Is there any interest in purchasing a kit of all parts to build an 
 extender cable.   With a moderate amount of interest the price  looks like it 
 would be around $20 per kit plus shipping (probably around $6 for shipping in 
 the US for as many that can be stuffed in a small priority mail flat rate 
 box... most serious TM500 users will want 2 cables for the wide modules).  
 Kit cables would be 18-19 long.   TM500 extender cables have been selling on 
 Ebay for $150-$350! 
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Re: [time-nuts] How are iPhones' clocks set under LTE?

[Bob Bownes]

Well, I seem to remember finding NTP running on my jail broken iPhone. But that 
was a few years ago. 

 On Aug 3, 2014, at 17:41, Tim Shoppa tsho...@gmail.com wrote:
 
 Unlike CDMA (where time distribution was an automatic part of the low-level
 protocol) I suspect the time displayed on many modern phones is not set by
 the telephony synchronous protocol but rather by IP-over-Wifi packets.
 
 And the packets don't seem to do a very effective job keeping the clock ont
 he phone correct. My employer gave me a Nokia Lumia 630 Windows Phone and
 its clock has always been off by at least a minute.
 
 There was a few years ago, a very nice article about the effort to repair
 the clocks in clock towers in many cities. What rang most true to me was
 if you visit a town they can't even keep the clock correct, who else knows
 what else is wrong there?.
 
 Tim N3QE
 
 
 On Sun, Aug 3, 2014 at 4:37 PM, Brian Garrett garrettbrian1...@gmail.com
 wrote:
 
 Hi all,
 
 First “time”r here.  This may not rank up there with your degree of
 time-nuttery, but I haven’t been able to get an answer elsewhere.  Recently
 I was discussing the issue of how the different cellular providers set
 their time, and I told him that I’d read that CDMA phones and towers have
 to have their clocks synced to GPS as part of the protocol, whereas GSM
 phones do not, and can theoretically be set to wall time, and thus phones
 on networks using CDMA would have atomic accuracy all the time since what
 they were getting was as good as GPS.
 
 Well, obviously I was pathetically behind the times.  Most everybody these
 days including Verizon, which both I and my friend have now, uses LTE , as
 you know.  I have looked all over for info as to what LTE’s time-setting
 requirements are, as implemented by Verizon, but I’ve not seen discussions
 of it anywhere.  I’ve seen amusing anecdotes over what can happen if your
 Android isn’t set to receive the network’s time, or what can happen to your
 phone’s clock if you live near a time zone boundary, but no discussion of
 how time dissemination is handled in-network.  I know my iPhone can be, and
 usually is, 2 or 3 seconds fast or slow when checked against an accurate
 reference clock, so I’m thinking they can just use wall time like GSM did.
 
 Has this been discussed on the list before?  I haven’t seen anything in
 the archives, and no-one at Verizon that we of the unwashed masses have
 access to will know the answer  Pointers, anyone?
 
 
 Thanks in advance,
 Brian
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[time-nuts] Data-chron 3070 manual

[Bob Bownes]

Anyone have a copy of the manual for a Data-Chron 3070? It's mostly pretty
obvious, bit there is a big I/O connector on the back it would be nice to
know the pinout of.

Thanks!
Bob
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[time-nuts] microcontroller based IRIG generator

[Bob Bownes]

I remember a few discussions over the last few years about building a
microcontroller (PIC, Arduino, MPS430, whatever floats your boat) based
IRIG generator. Did anyone ever get one working?


Thanks!
Bob
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Re: [time-nuts] hp 54600a and rs-232

[Bob Bownes]

Yup, set your program to 7E2 and test it.

I would fire up a terminal program like hyperterm and see if you can talk
to it manually before anything else. With only four baud rates to check, it
isn't too many combinations. Not many things support split baud rates
(different rate for rx and tx), but if it does, make sure they are the
same.

You can also try looping back the tx/rx pins on the rs232 port from the
computer to check that out standalone first. That should work at any baud
rate and parity setting.


Bob


On Tue, Apr 22, 2014 at 11:07 AM, Collins, Graham coll...@navcanada.cawrote:

 The scope has four choices for baud rate and otherwise is 8 databits, 1
 stop bit, and no parity.

 I am not sure I understand what you are suggesting with the 7E2 - set my
 program to use 7 data bits EVEN parity and 2 stop bits?

 Cheers, Graham


 -Original Message-
 From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
 Behalf Of bownes
 Sent: April-22-14 10:48 AM
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] hp 54600a and rs-232

 Framing error or override sounds like a parity or stop bit issues.
 Have you changed those at all? 7E2 often works when 8N1 is specified.

  On Apr 22, 2014, at 10:34, Collins, Graham coll...@navcanada.ca
 wrote:
 
  Thank you Thomas,
 
  I have that document but it wasn't of much help. I spent much time over
 the weekend reading through the various hp documents for this scope and
 interfaces but it did not shed any light on the subject.
 
  Cheers, Graham
 
 
 
  -Original Message-
  From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]
  On Behalf Of Tom Knox
  Sent: April-22-14 10:28 AM
  To: Time-Nuts
  Subject: Re: [time-nuts] hp 54600a and rs-232
 
  This may help:
  http://cp.literature.agilent.com/litweb/pdf/54652-97004.pdf
 
  Thomas Knox
 
 
 
  From: coll...@navcanada.ca
  To: time-nuts@febo.com
  Date: Tue, 22 Apr 2014 07:21:22 -0400
  Subject: [time-nuts] hp 54600a and rs-232
 
  While only related to time nuttery in the sense of the hp 54600a being
 an instrument (oscilloscope) which we nuts might use make some meaningful
 measurements, I am hoping that members of this list vast knowledge of many
 such instruments may be able to help or at least point me in the right
 direction.
 
  I recently obtained a hp 54600a digital oscilloscope in very good
 condition and while not a modern whiz bang high bandwidth and high speed
 instrument it is quite capable and compliments my old Tektronix 5440 scope
 quite nicely.
 
  My 54600a has the basic RS-232 interface module which seems to work OK.
 I am able to select print screen and send data from the scope to an HP
 plotter or printer - computer actually which collects the data stream and
 converts the hgl data into a png file using a simple script.
 
  However, my attempts at getting the scope to respond to commands via
 the RS-232 serial interface are for naught. I am using a USB to RS-232
 converter and an appropriate null modem cable. I don't have a proper serial
 port to try however.
 
  When I send commands to the scope it will display framing error or
 overrun or rs-232 error (113) or rs-232 error (118) (I can't find
 either error code listed in the hp documents).
 
  Being able to capture a screen dump is my primary concern and I am
 able to do so, controlling the scope via rs-232 as I might using a
 gpib/hpib interface is only secondary  but still, it would be nice to know
 why my limited attempts have so far not worked.
 
  Ideas? Comments? Suggestions?
 
 
  Cheers, Graham ve3gtc
 
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Re: [time-nuts] A small piece on HP's hydrogen maser in 1968

[Bob Bownes]

Lot's of connectors change specification @ 18Ghz or are not rated bast
18Ghz.




On Tue, Feb 25, 2014 at 11:55 PM, Hal Murray hmur...@megapathdsl.netwrote:


 jim...@earthlink.net said:
  there's a BIG jump in  cost when you cross that 18GHz boundary line.

 What's magic about 18 GHz?  Why not 16 or 20?


 --
 These are my opinions.  I hate spam.



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Re: [time-nuts] Clock Driver Design

[Bob Bownes]

TV video distribution amps work very nicely. Even better if you open them
up and change the matching from 75ohm to 50. :)

Bob



On Thu, Sep 26, 2013 at 3:19 PM, Glenn Little WB4UIV 
glennmaill...@bellsouth.net wrote:

 Would an analog video distribution amplifier work?
 These are available cheap.
 TV stations used these eight or so in a frame.
 The frame had a power supply and the BNC i/o connectors.
 Each da would drive 6 or 8 outputs.

 73
 Glenn
 WB4UIV
 Retired TV CE.



 At 01:28 PM 9/26/2013, you wrote:

 I am looking into various degrees of craziness.  The source is CMOS and
 there are plenty of 1 in to N out parts designed to drive clocks on a PCB
 but not much is said about driving clocks on to a random length of coax to
 another piece of equipment and what additional precautions that might
 warrant.  I am also considering making a sine wave output and maybe other
 frequencies.
 Tom

 On 9/26/2013 4:34 AM, Bob Camp wrote:

 Hi

 Standard high speed CMOS logic works pretty well. How crazy are you
 trying to get?

 Bob

 On Sep 26, 2013, at 1:48 AM, Tom Minnis tom_min...@att.net wrote:

  I am working on a small clock distributor and wanted to get some ideas
 on what works best for 10MHz and 1PPS driver circuits.  I remember sifting
 through the archives a year or so ago and tripped on some discussion of
 this but I can't find it anymore.
 Tom
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Re: [time-nuts] NTP/1-PPS/RS232 question

[Bob Bownes]

Exactly. And, as someone else pointed out, you then need to delay it 900 ms to 
put it back in the right place, which would take a lot of gate delay. This is 
time nuts after all...

On Sep 8, 2013, at 11:08, Chris Albertson albertson.ch...@gmail.com wrote:

 You only need ONE inverter gate.
 
 The purpose is the flip the pulse.  The MAX 232 chip flips the logic
 once which works fine for the data but you need to flip the control
 lines (maybe if the GPS reciever did not already do this for you.)
 
 Flipping the PPS has the effect of moving the pulse by the length of
 the pulse so one gate in this case will move the pulse by 100MS.
 
 On Sat, Sep 7, 2013 at 9:22 PM, Bob Bownes bow...@gmail.com wrote:
 100ms is an awful lot of 'inverter gates'!
 
 On Sep 7, 2013, at 23:15, Chris Albertson albertson.ch...@gmail.com wrote:
 
 With RS232 the data uses negative logic (low is 1) and the control
 lines use positive logic (high is 1.)   That is, a control line is
 asserted when it is at logic 0, a positive voltage.
 
 Some one at one time must have thought this made sense.
 
 The good news is that a mistake is easy to detect and fix.  If the
 pulse is 100MS long and you have it inverted then your time will be
 off by 100MS.   When you are designing the board put in some extra
 inverter gates
 
 On Sat, Sep 7, 2013 at 7:15 PM, Mark Sims hol...@hotmail.com wrote:
 I got in those Adafruit GPS boards.  They are a very nice little GPS.   
 VERY sensitive.  I could get good lock indoors on my (windowless) kitchen 
 floor.  The house is 2 story,  stucco with wire mesh in the stucco.   I 
 could also get lock in a restaurant that had a tin roof.  We were far from 
 any windows.
 The 1PPS signal is normally low and pulses high for 100 milliseconds.  The 
 RS-232 adapter board that I built feeds this into an RS-232 transmitter 
 chip (MAX3232),  so on the interface connector CD will be at +V and pulse 
 down to -V.  Is this what stock NTP likes?
 Also,  I laid out the adapter board so it an accommodate a Trimble 
 Resolution T or a Crius CN06 receiver.  The Crius receiver uses a U-Blox 
 NEO-6M receiver.  They can be had for around $22 at HobbyKing.   They seem 
 to perform even better than the AdaFruit module.  It looks like you will 
 need to bodge a wire onto the TIMEPULSE pin to use it for 1PPS.
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 Redondo Beach, California
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 Chris Albertson
 Redondo Beach, California
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Re: [time-nuts] NTP/1-PPS/RS232 question

[Bob Bownes]

100ms is an awful lot of 'inverter gates'! 

On Sep 7, 2013, at 23:15, Chris Albertson albertson.ch...@gmail.com wrote:

 With RS232 the data uses negative logic (low is 1) and the control
 lines use positive logic (high is 1.)   That is, a control line is
 asserted when it is at logic 0, a positive voltage.
 
 Some one at one time must have thought this made sense.
 
 The good news is that a mistake is easy to detect and fix.  If the
 pulse is 100MS long and you have it inverted then your time will be
 off by 100MS.   When you are designing the board put in some extra
 inverter gates
 
 On Sat, Sep 7, 2013 at 7:15 PM, Mark Sims hol...@hotmail.com wrote:
 I got in those Adafruit GPS boards.  They are a very nice little GPS.   VERY 
 sensitive.  I could get good lock indoors on my (windowless) kitchen floor.  
 The house is 2 story,  stucco with wire mesh in the stucco.   I could also 
 get lock in a restaurant that had a tin roof.  We were far from any windows.
 The 1PPS signal is normally low and pulses high for 100 milliseconds.  The 
 RS-232 adapter board that I built feeds this into an RS-232 transmitter chip 
 (MAX3232),  so on the interface connector CD will be at +V and pulse down to 
 -V.  Is this what stock NTP likes?
 Also,  I laid out the adapter board so it an accommodate a Trimble 
 Resolution T or a Crius CN06 receiver.  The Crius receiver uses a U-Blox 
 NEO-6M receiver.  They can be had for around $22 at HobbyKing.   They seem 
 to perform even better than the AdaFruit module.  It looks like you will 
 need to bodge a wire onto the TIMEPULSE pin to use it for 1PPS.
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 -- 
 
 Chris Albertson
 Redondo Beach, California
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Re: [time-nuts] SDR Radio Opinion ?

[Bob Bownes]

They also make nice panadapters...

On Aug 5, 2013, at 17:25, Lizeth Norman normanliz...@gmail.com wrote:

 Gents,
 These things are limited in usefulness by themselves. They need decent
 filtering and preamps for any weak signal stuff.
 If all you want to do receive the local channels, then these are for you!
 Norm n3ykf
 
 On Mon, Aug 5, 2013 at 5:21 PM, Don Latham d...@montana.com wrote:
 
 About $85 US. But a TV tuner type is about $24.
 
 J. Forster
 Has anyone played with this thing?
 
 http://microsat.com.pl/product_info.php?products_id=35
 
 If you add a laptop, is the thing a complete radio? It seems to be far
 too
 cheap to believe.
 
 -John
 
 ===
 
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 --
 “The power of accurate observation is commonly called cynicism by those
 who have not got it.”
 -George Bernard Shaw
 
 
 
 Dr. Don Latham AJ7LL
 Six Mile Systems LLC
 17850 Six Mile Road
 POB 134
 Huson, MT, 59846
 VOX 406-626-4304
 Skype: buffler2
 www.lightningforensics.com
 www.sixmilesystems.com
 
 
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Re: [time-nuts] Good (cheap) PIC chip choice for project?

[Bob Bownes]

I suspect Linux based systems are a few sigma away from the original goal of a 
cheap pic choice...:)

But to get back to the original point, you can get samples of most of the PIC 
chips from MicroChip for free. I think the limit is 3 per week. Or 30 days, I 
don't remember.

Bob

On May 25, 2013, at 20:36, Bob Camp li...@rtty.us wrote:

 Hi
 
 If you want Linux, you probably also want something like an A9 or better. The 
 M0 and even the M4's MCU's are not really targeted at Linux. Can you pack it 
 into a big M4 - sure, it'll be a tight fit and you may not have everything 
 you really wanted to have. Oddly enough some of the M4's have better native 
 ethernet than some of their big brothers. Weird….
 
 Bob
 
 On May 25, 2013, at 8:12 PM, li...@lazygranch.com wrote:
 
 If you go arm cortex and linux, you will need to make your code a service. 
 You will want it to start up by itself and if for some reason it crashes, 
 you will want it to restart itself. The buzzword is harden and the 
 techniques vary depending on the distribution.
 
 You should check the architecture of the system. I didn't realize many of 
 these boards run the ethernet off the usb hub. My recollection is the a10 
 used by Allwinner does not do that.
 
 Opensuse has JEOS, which stands for Just Enough OS. Less is more!
 
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Re: [time-nuts] Time Nut Pickens at the MIT Flea ?

[Bob Bownes]

We should plan a Time-Nuts BOF lunch after the next flea. 

Saw little TN gear @ Dayton save one Efretom RBI time base for $1800 and a few 
10811s of dubious quality for $50 ea. the dents put me off gambling on one 
since I was given or the afternoon before! ;)

On May 19, 2013, at 21:50, paul swed paulsw...@gmail.com wrote:

 Hello to the group.
 I did see the leitch video DA's. Was a good price if the DA's were in the
 case. The other thing to watch out for is that Leitch made all types of DAs
 digital also. You want the simple vide monitoring DA, Equalizing DAs are OK
 also delays are a pain.
 
 John it was good to see you and Jim. Great Wx.
 
 As for the pickens not much at all. I picked up to EGG RB oscillators and
 warming one up right now to see if it will work. At $20 each worth a try.
 Other then that parts and the real find a HPIB frame for Tek modules for
 $20. Been looking for one for quite a while.
 But really little time-nuttery stuff.
 
 Stan one day one way or another would be good to run into you. I also did
 not see Paul. (The other one who is also a slight time nut)
 Regards
 Paul
 
 
 On Sun, May 19, 2013 at 6:55 PM, Andy Bardagjy a...@bardagjy.com wrote:
 
 I grabbed a real nice Leitech distribution amplifier - but I took it home
 and it was empty!
 
 I walked back and returned it for a refund, but the seller said he had a
 whole stack in his office. I was gonna post to the list when I sort it out
 - it was a real bargin, and he said he might be willing to ship them
 around.
 
 Andy Bardagjy
 bardagjy.com
 
 
 On Sun, May 19, 2013 at 4:42 PM, Stan, W1LE stanw...@verizon.net wrote:
 
 Anyone  got any Time Nut quality items at the MIT fleamarket today ?
 
 Stan, W1LE   Cape Cod
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Re: [time-nuts] Needed: The Real Serial USB Fix

[Bob Bownes]

There are some well documented issues with timing and USB that have been
rehashed here a few times.


On Sun, Jan 27, 2013 at 1:48 PM, Jim Lux jim...@earthlink.net wrote:

 On 1/27/13 9:30 AM, Peter Gottlieb wrote:

 At work we simply use multi port serial cards (*no* USB intermediary) or
 Ethernet to serial adapters.  Any use of USB for critical test equipment
 was pretty much banned here years ago.


  Why the proscription against USB?
 Because of difficulty with USB device drivers? Or the plethora of serial
 port emulators that have unforeseen interactions with software that thinks
 it's talking to a real serial port? or what?




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Re: [time-nuts] 10 MHz - 16 MHz clock multiplier

[Bob Bownes]

Paul Wade built a board recently to do just this. www.w1ghz.org.

Bob


On Fri, Jan 4, 2013 at 12:16 PM, Chris Albertson
albertson.ch...@gmail.comwrote:

 THis is exactly what they are talking about the 74HC390 can do over
 50MHz and costs abut 30 cents.  You don't need ECL or anything so
 exotic the 30 cent part will work.   Set it for divide by 5.  I guess
 this is imperfect enough that there is some fourth harmonic content in
 the 2MHz square wave, then you select that with a narrow band filter
 and amplify it to whatever you need.   A smart design might try and
 add fourth harmonics be using a slightly not-symetric 2MHz square wave

 My question is about the phase noise of the final 16MHz signal.  Do
 crystal filters clean up the signal.  It seems that after several
 16MHz crystals in series the output should look a lot like an XO.

 On Thu, Jan 3, 2013 at 6:02 PM, Tom Miller tmil...@skylinenet.net wrote:
  Isn't there a fast divide by N counter that you could set to 10? Maybe
 even
  in ECL?
 
 
  - Original Message - From: David davidwh...@gmail.com
  To: Discussion of precise time and frequency measurement
  time-nuts@febo.com
  Sent: Thursday, January 03, 2013 8:49 PM
  Subject: Re: [time-nuts] 10 MHz - 16 MHz clock multiplier
 
 
 
  They do not exist as I found out (again) not long ago.  The last 7490
  made was LS (low power schottky) and I use quite a few of them.
  Actually, I have seen a datasheet for a 74HC90 and 74HCT90 but they
  apparently either never went into production or very few were
  produced.
 
  The closest non-TTL alternative that I found was the 74HC390 or
  74HCT390 which is basically two 7490 counters in one package.
 
  On Fri, 04 Jan 2013 11:59:01 +1100, Max vk3...@gmail.com wrote:
 
  Where can one get some of these mythical  74HC90 's and 74AC90 's that
  have been mentioned.
   None of the usual places have them, ie ebay, digi-key, farnell, or
  even the Chinese.
   Also data-sheets are not to be found.
  Thanks
 
 
 
  On 4/01/2013 5:13 AM, Bill Fuqua wrote:
 
  One way is to divide by  10 and then multiply by 16.
  Divide by 10 and then follow by 4 tuned frequency doublers.
  This should introduce little phase noise.
  Another way to do it is to divide by 10, then pass the output thru
 a
  narrow 16 MHz filter and amplify. Sounds difficult but the filter can
  be one
  or two 16 MHz crystals followed by a simple amplifier. Look at the
  reference input circuit for a PTS-160.  The output of the divide by 10
  needs to
  be asymmetrical so it produces even harmonics. If you are using a
  divide divide by 52 such as a 74HC90, divide by 2 first then by 5.
   Ideally the pulse width should be a half period of 16 MHz for the
  maximum harmonic content at 16 MHz.
  You can take the output of the frequency divider and send it to a
  NAND gate.
  One input of the gate is directly connected and the other is delayed.
  You can
  use an RC with a variable capacitor to ground to get it just right.
  Just adjust the capacitor to get the maximum output from your
  filter amplifier.
  73
  Bill wa4lav
 
 
 
  At 07:41 PM 1/2/2013 +, you wrote:
 
  What's the simplest way to generate 16 MHz from 10 MHz? This will be
  for clocking a microcontroller at 16 MHz given 10 MHz (Cs/Rb/GPSDO).
  Low price and low parts count is a goal; jitter is not a concern but
  absolute long-term phase coherence is a must.
 
  The ICS525 (as in TAPR Clock-Block) is a good candidate but I was
  wondering if there's something cheaper, less functional, and maybe
  not SSOP. Any suggestions?
 
  Thanks,
  /tvb
 
 
 
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 --

 Chris Albertson
 Redondo Beach, California

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Re: [time-nuts] Tracking NTP displacement and correlation betweentwo clients.

[Bob Bownes]

David,

The problem is that they start in sync and over the course of a day drift that 
far apart despite having NTP running. We're not sure why NTP isn't correcting 
it along the way. Though at this point, we are looking at a firmware bug.

Thanks!
Bob

On Oct 5, 2012, at 12:30 AM, David J Taylor david-tay...@blueyonder.co.uk 
wrote:

 The problem stems from one of the two (identical) machines drifting off by
 60-70 seconds per day. So a few ms here and there are ok.
 []
 Bob
 ==
 
 Bob,
 
 NTP is normally limited to a +/- 500 parts per million correction - 43 
 seconds per day.  You may be operating outside the range NTP is expecting to 
 handle.  If the clock offset is a stable value of 60-70 seconds per day you 
 can bias NTP to correct within +/- 500 ppm of that drift.
 
 Cheers,
 David
 -- 
 SatSignal Software - Quality software written to your requirements
 Web: http://www.satsignal.eu
 Email: david-tay...@blueyonder.co.uk 
 
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Re: [time-nuts] Tracking NTP displacement and correlation between two clients.

[Bob Bownes]

On Thu, Oct 4, 2012 at 12:46 PM, Hal Murray hmur...@megapathdsl.net wrote:


 bow...@gmail.com said:
  Due to reasons I really can't go into, a systems user is concerned with
 the
  displacement of two servers from the same pair of stratum 2 NTP servers.
 redacted



 Assuming you are running the standard ntpd...  It includes all sorts of
 logging.

 Set up the two systems so they use each other as servers.   Turn on
 rawstats.
  ntpd will add a line each time it exchanges a pair of packets with a
 server.
  That line will have the IP Address and 4 time stamps.  See the
 documentation.  Details are in monopt.html  The 4 time stamps are:
   time the request left the local system
   time the request arrived at the remote system
   time the response left the remote system
   time the response arrived at the local system

 That looks like a bit of overkill. :)


 If you subtract the first two, you get the network transit time for the
 request packet as skewed by the clock offset.  Subtracting the last two
 gives
 you the transit time for the response packet.

 If you assume the network transit times are equal, you can compute the
 clock
 offset.  If you are on a LAN, the transit times will probably be tiny on
 the
 scale of 10s of ms.


In this case, the transit times should average out be very very close. The
two machines in question are plugged into adjacent network ports with the
same length of cable and the NTP server is on the same (lightly loaded) sub
net.

The problem stems from one of the two (identical) machines drifting off by
60-70 seconds per day. So a few ms here and there are ok.


How good is your connection to the big bad internet?  If you run a big
 download over a slow link, the queuing delays can confuse ntp.  You might
 want to look at the timings from your systems to the stratum-2 servers
 and/or
 from the stratum-2 servers to the outside world.


This is all relative to two internal stratum 2 servers on the same command
and control network. No large xfers allowed over it. There are physically
separate data, backup, and application networks for that.

Thanks for the suggestions folks. I'm going to look into some of the
standard ntp logging stuff as well as the scripts that John offered up. And
now, I'm probably going to have set something up to start comparing my 3
GPSDO's and their associated machines! :)

As an aside, I have seen that someone on the Raspberry Pi list has NTP
running with 1pps into the GPIO ports. I've got a stack of GPS modules in
stock with 1pps that are just itching to be tied to one of those, also in
stock. Maybe this weekend.

Bob
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Re: [time-nuts] Tracking NTP displacement and correlation between two clients.

[Bob Bownes]

On Thu, Oct 4, 2012 at 1:31 PM, Attila Kinali att...@kinali.ch wrote:

 On Thu, 4 Oct 2012 13:04:27 -0400
 Bob Bownes bow...@gmail.com wrote:

  The problem stems from one of the two (identical) machines drifting off
 by
  60-70 seconds per day. So a few ms here and there are ok.

 Is it drifting without ntp or with ntp?
 1minute drift per day is not unheard of for standard PC RTCs.. i've seen
 even worse..



With. Hence the issue.

redacted


 So, if you have any significant time difference (1ms) between two systems
 that synchronize to the same NTP server in the same LAN, then the
 problem lies somewhere else than the network.


Exactly where I am at this point. Dozen of other systems in the same
facility don't seem to have this issue.
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Re: [time-nuts] Lady Heather on a Laptop

[Bob Bownes]

I run an XP VM in either VirtualBox (under linux) or Parallels (on my mac)
to do the same thing. Works like a charm.

Bob


On Thu, Sep 27, 2012 at 11:00 AM, paul swed paulsw...@gmail.com wrote:

 My I like your approach.
 Now I have to go see what all of this might cost.
 On vmware are you running esxi??
 Suspect the atoms are costly
 Regards
 Paul
 WB8TSL

 On Thu, Sep 27, 2012 at 10:58 AM, Chris Albertson 
 albertson.ch...@gmail.com
  wrote:

  I have an Intel Atom powered box that runs Linux.  These Atom CPUs use
  so little power they don't put fans on the CPU heat sinks.  I run
  VMware on Linux and then Windows XP inside the virtual PC.  LH runs on
  Windows in the virtual machine.  I have removed the monitor, keyboard
  and mouse.  The entire setup uses about 5 or 6 watts of power
 
  If I want to see the LH display I can log into the linux system for
  any other computer and have the screen exported.
 
  Chris Albertson
  Redondo Beach, California
 
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Re: [time-nuts] Javad's J-Shield

[Bob Bownes]

It isn't an article. It's an 11 page ad. Notice there are no magazine page
footers and the formatting is not the same as articles. Most 'reputable'
publications would now put 'Advertisement' at the bottom of each page.

Bob



On Fri, Sep 21, 2012 at 9:35 AM, Rob Kimberley
robkimber...@btinternet.comwrote:

 I understand fully what Javad said, having followed the LightSquared
 debacle
 recently. I just thought that the article was very biased and somewhat
 derogatory in its reference to other parties.

 Rob

 -Original Message-
 From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
 Behalf Of Larry McDavid
 Sent: 19 September 2012 17:28
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] Javad's J-Shield

 Yes, interesting. But, note that article is also a political statement by a
 highly-biased individual owning a related business.

 I'm not saying he is wrong or even that I disagree. I do believe it is
 worthwhile to know who is saying what.

 Larry

 On 9/19/2012 7:07 AM, Rob Kimberley wrote:
  Page 19 - 30  in the latest edition of GPS World.
 
  http://editiondigital.net/publication/?i=125872
 
  Interesting read..
 ...

 --
 Best wishes,

 Larry McDavid W6FUB
 Anaheim, California  (SE of Los Angeles, near Disneyland)

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Re: [time-nuts] Reducing lab noise with LED lighting.

[Bob Bownes]

AllElectronics has has some ~24, 24 white LED white strips available for
about $7 of late. I purchased a bunch and stick them under the lips of the
shelves in my office/lab and powered them with an old laptop brick I had
sitting about. Look great, wickedly cheap, and very effective, especially
at night.

On Mon, Sep 17, 2012 at 11:10 AM, Raj vu2...@gmail.com wrote:

 As even LED have switchers in them, look for 12V LED spot lamps which run
 on AC/DC and give them a try. They have 3 LEDs and I don't think they have
 a switcher PS. A 12V transformer PS will work without filter cap IMHO. Low
 noise !

 At 17-09-2012, you wrote:

 In this green era here in the USA there is a big push toward CFL
 lighting. Problem is I can see my CFL lighting on my PN measurements and
 other equipment. I am finding it is very noisy so I have started
 researching cost effective LED lighting and was amazed at what is
 available. On eBay there are 10 to 100 watt raw chips for $2-25.00  but
 that is equal to about 5 times the lumen of incandescent lighting. I was
 going to try building the heat sinks and supply into my existing bench
 fixtures.
 I will post more info soon.
 Thomas Knox


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Re: [time-nuts] web presentation of data

[Bob Bownes]

If you are looking to graph long running data and provide rolled up
summaries, the combination of MRTG and RRDtool is pretty hard to beat. Can
work with pretty much anything on the back end. And it's the industry
standard for network monitoring.

http://oss.oetiker.ch/mrtg/doc/mrtg.en.html

Or some examples:

http://www.switch.ch/network/operation/statistics/geant2.html



On Tue, Aug 7, 2012 at 10:04 AM, shali...@gmail.com wrote:

 Regarding plotting data files through a web page, some time ago I wrote a
 small utility to do just that. We have a corona tester here at my workplace
 that generates binary files with the corona data. These are not easily
 plotted from a standard tool because of the proprietary format.

 Instead of writing a Visual something program that would have to be
 installed on all the machines that might need to display the data, I wrote
 a php app that I loaded on the local Linux server.
 I also copied it to my ko4bb.com site at http://www.ko4bb.com/graph

 You can try it with this file (which you need to download to your local
 hard drive first, so that you can upload it to the tool :)

 http://www.ko4bb.com/graph/**006.DAT http://www.ko4bb.com/graph/006.DAT

 This software could be easily modified to print any standard file format
 (comma delimited or else) and to adjust the width/height of the picture to
 your liking. Save the picture size in a cookie so that you do not need to
 enter it each time and you are done :)

 The source code is there:

 http://www.ko4bb.com/graph/**index.php.txthttp://www.ko4bb.com/graph/index.php.txt

 Didier KO4BB


 On , John Ackermann N8UR j...@febo.com wrote:

 I think there are now a couple of threads going on about this topic,
 which I started by a clumsy attempt to use the WIDTH and HEIGHT
 attributes in HTML. :-)




  For what it's worth, I usually scale web graphics to no larger than 750
 pixels horizontal or 550 pixels vertical. That goes back to the days of
 lower resolution monitors, but still works well with the page layout I use
 at febo.com.




  The challenge in this case was that using the default settings in John's
 TimeLab program, I'm getting plots that are about 1350 pixels wide and (as
 PNGs) are ~130kB in size. When down-sampled, it can become difficult to
 read the fine data. The best way to handle that, I think, is to create a
 scaled version of the image and use that as a link to the full-size
 version. Something like:








  But that's extra work that I haven't gotten around to automating yet, so
 I thought I'd try using the HTML size options:








  The viewer can then right-click on the image and via the view image or
 similar menu open up the full-sized version for the fine detail. That
 worked on my browser and monitor, but apparently not on some other
 combinations. So, it's back to the drawing board.




  Moving to the second thread on plot generation generally, apart from
 TimeLab I do most of my data capture and analysis in Linux. I typically
 break the two into separate pieces:




  1. A single-purpose program (usually written in Perl because I make
 slightly fewer errors with it than other languages) that talks via GPIB or
 serial port and outputs a data file with typically MJD and phase or
 frequency information.




  2. A graphing tool that reads the data file. For this, I'm quite fond of
 a program called Grace 
 (http://plasma-gate.weizmann.**ac.il/Grace/http://plasma-gate.weizmann.ac.il/Grace/)
 that provides a WYSIWIG graphics interface and saves plot information in an
 ASCII format that's pretty easy to muck around with. Grace is packaged with
 Debian-based Linux distributions; I don't know if there's a Windows version
 available.




  I've also done some automatic plot generation to go from data file to
 regularly updated web page. This involves some fairly ugly text processing
 taking advantage of Grace's batch mode, but the result is a tool that will
 read the data file, do whatever statistics are desired, combine with the
 Grace command file, run Grace in batch mode, and create an output PNG file
 that's uploaded to the web. It's actually fairly easy to do once you figure
 out the appropriate black magic...




  John


  




  On 8/6/2012 11:34 AM, Jim Lux wrote:



  what would be useful is to have some sort of plotting engine that is a


  canned webpage (or stored locally on the user/client computer) that can


  ingest fairly raw data from a URL..




  something, conceptually, like this:








  *invocation of plotting engine*




  data value 1


  data value 2


  data value 3








  that way, a relatively dumb controller (think arduino-ish) could talk to


  the instrument and build a web page on the fly without having to do much


  formatting. The java/javascript/whathaveyou would do all the plotting


  work on the client side (where, presumably, they have a display and some


  computational horsepower to drive it)




  A low end microcontroller has no problem serving 

Re: [time-nuts] Cables dor 10 mHz

[Bob Bownes]

Old ThinNet was coax, as was ThickNet before it. Only in the Modern Age
have they been using twisted pair. :)


On Mon, Jul 30, 2012 at 3:41 PM, Sylvain Munaut 246...@gmail.com wrote:

  10 mHz

 Please use MHz   ...

 10 mHz is 10 milli-hertz, ie 1 cycle every 10 second.


 An yes, ethernet not being coax cables, I'd expect them to act as
 antennas quite a bit ...


 Cheers,

 Sylvain

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Re: [time-nuts] Trimble T Lassen 2 - suitableantenna....advice.....questions

[Bob Bownes]

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 scope does not sync on athe1Hz
 pulse.  You have to breadboard something that will detect it, maybe a
 flip flop and then look at the FF's output.

 On Mon, Jul 23, 2012 at 9:49 AM, Azelio Boriani
 azelio.bori...@screen.it wrote:
  ...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 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: Monday, July 23, 2012 12:11 PM
  To: time-nuts@febo.com
  Subject: [time-nuts] Trimble T Lassen 2 -
  suitableantennaadvice.questions
 
 
   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 power to both units I can hear the oscillator (12.504
  MHz) on my comms RX. So I am assuming that they work.
 
  I bought what claims to be a Trimble compatible active antenna on
  EBay. I hooked it up to one of the boards and applied power, and put
  the scope on the one pps pin. However after 20 mins (which I assume is
  much longer than the unit requires to get a lock) I see no 1pps trace
  on the screen. :-(
 
  So my working assumption is that the antenna is not working. The
  antenna position is fine as my elderly Garmin GPS2 which must be 12
  years old sees 6 satellites there.
 
  Can anyone recommend a suitable antenna? I have a number of DIY
  designs I can try (Patch, Turnstile) but the Trimble docs say it needs
  an active antenna so I guess I'll have to spend money :-(
 
  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.
 
  Lastly, has anyone found a GPS that will work with an Ipad. What the
  man in the Apple shop failed to tell me was the non 3g model lacked
  the built in GPS :-(
 
  Thanks in advice
 
  Steve
 
 
 
  --
  Wisdom demands a new orientation of science and technology towards the
  organic, the gentle, the non-violent, the elegant and beautiful. E. F.
  Schumacher
 
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 --

 Chris Albertson
 Redondo Beach, California

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Re: [time-nuts] [OT] Paywall Rant (was Re: Spoofing GPS)

[Bob Bownes]

The fact that a clause is not enforceable doesn't prevent it from being put
in contracts to scare non lawyers. I had my personal attorney, who happens
to work for a firm that has another atty that specializes in employee/union
side labor law, review one of my employment contracts once. His opinion was
that the vast majority of it was unenforceable in the state I resided in
and it had clearly been written in a not so labor friendly state. Later in
life I asked him to write the employment contracts for a startup and he was
almost visibly uncomfortable. But once I explained I wanted 'fair and
bilaterally binding' contracts, he did a great job and saved a number of
folks when we sold the company.

On a more time nuts front, I have ntpd running on my new RasPi. Next step,
using the GPIO pins for the 1pps instead of a USB serial dongle.

Bob



On Thu, Jun 28, 2012 at 11:02 AM, jmfranke jmfra...@cox.net wrote:

 When I was in college, I worked part time on the engineering staff of
 several AM broadcast stations. The employment contract forbid me from
 working at another station within 250 miles if I was dismissed or resigned.
 The clause was not limited to just the on-air personnel.

 John  WA4WDL

 --**
 From: Peter Gottlieb n...@verizon.net
 Sent: Thursday, June 28, 2012 10:46 AM
 To: time-nuts@febo.com
 Subject: Re: [time-nuts] [OT] Paywall Rant (was Re:  Spoofing GPS)

  I support that law.  What a waste of talent if bright stars in advancing
 fields are snuffed out!

 Interestingly, I once heard it mentioned (in a business roundtable
 meeting) that this was one of the anti-business laws which must be
 strongly fought against.

 You are right though, just because there is precedent does not stop
 companies and their lawyers from inserting such clauses into their terms of
 employment, most of which are non-negotiable for engineers.  The question
 is, how many individuals can afford going to court, both in terms of cost
 as well as time?  And courts are unpredictable, so you might even lose and
 be destroyed financially.  Thus, specific laws codifying such employee's
 rights are great.  Perhaps such anti business laws played a part in the
 high-tech buildup in CA.

 Peter



 On 06/28/12, Jim Luxjim...@earthlink.net wrote:

 On 6/28/12 6:38 AM, Peter Gottlieb wrote:

 Very true, and in some cases (Texas case) a judge ruled that an employee
 that left a firm can never work in that same field again for the rest of
 their life due to both positive and negative knowledge.


 Not in California, where such agreements are specifically prohibited by
 law.

 And, for that matter, the later legal strategy calling out inevitable
 disclosure (that is, that if you work in the same field you will
 inevitably disclose something that is trade secret) has been held
 invalid in a variety of courts.

 This doesn't stop company A from threatening to sue Company B who wants
 to hire someone from Company A, but it turns the threat into nothing, if
 Company B's lawyer writes a nice letter citing the half dozen or so
 cases to Company A's lawyer. In effect telling A, pound sand with your
 stupid extortion

 It *is* still effective in the old boys network.. executive from company
 A mentions to executive from company B, you know, if you hire good ol'
 Bob, it could get sticky, legally. You sure you want to take that on.
 Of such are things like illegal anti-poaching agreements made and of
 such are consent decrees issued.

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Re: [time-nuts] Serial port server .. any interest in a write up onusing ?

[Bob Bownes]

I use the lantronix serial to ethernet converters and I use Xylogix
terminal servers. I've not had much luck getting either to work with
classic windows based applications, though I'd love to do so as I have a
plethora of both.

I use a 64 port xylogix in the basement to connect to all the serial ports
of various servers, routers, and other old or embedded gear without
ethernet. It does that job very very well.



On Tue, May 22, 2012 at 11:37 AM, li...@lazygranch.com wrote:

 My solution is 100% compatible with the OS. That is, no special drivers.

 I have had issues with some programs using virtual ports.

 Magma boxes were common in digital audio recording prior to really wide
 (multichannel) sound cards. I've run 5 soundcards at a time under linux
 with the Magma box. Any kernel 2.6 or higher can use the Magma scheme. It
 also runs on win2k and win7. Mac too in theory, but I don't use Apple
 hardware so I can't verify this.



 -Original Message-
 From: Azelio Boriani azelio.bori...@screen.it
 Sender: time-nuts-boun...@febo.com
 Date: Tue, 22 May 2012 14:19:38
 To: Discussion of precise time and frequency measurement
 time-nuts@febo.com
 Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
 Subject: Re: [time-nuts] Serial port server .. any interest in a write up
  onusing ?

 There are Lantronix CoBox, XPort too and the TIBBO. Something like
 ebay 370532038785,
 290714846432 for those of you in the States or 270711839584 for the Europe.
 They are one_serial_port-to-ethernet adapter based on the telnet protocol
 but Lantronix has a virtual COM port driver to translate the ethernet
 attached serial port into a normal COM port on your PC.

 On Tue, May 22, 2012 at 2:14 PM, li...@lazygranch.com wrote:

  For the maximum software compatibility, I'd go for the multiple port
  serial card. Next step up would be a PCI expansion chasis like a Magma
  using multiple serial cards. I got one on ebay and PCI slots work like
 the
  real thing under both linux and windows. I use it for multiple
 soundcards,
  but it works for any PCI card.
  The only trick is to power the PCI expansion chassis before booting.
 
  -Original Message-
  From: J. L. Trantham jlt...@att.net
  Sender: time-nuts-boun...@febo.com
  Date: Tue, 22 May 2012 06:54:02
  To: 'Discussion of precise time and frequency measurement'
  time-nuts@febo.com
  Reply-To: Discussion of precise time and frequency measurement
 time-nuts@febo.com
  Subject: Re: [time-nuts] Serial port server .. any interest in a write up
 onusing ?
 
  Pete,
 
  I would like to hear more about this.  Consider me an infant in 'network'
  and use really simple terms.
 
  I have an old Dell computer that runs Win2KPro with two serial ports
 built
  in that was discarded by my office.  I use it to communicate with a TBolt
  and a Z3816A.  The ability to communicate with several other serial ports
  would be beneficial but the thought of getting several PCI/Serial cards
 for
  the computer seemed like the only option.  I would love to hear of other
  options, particularly for 'pennies'.
 
  Joe
 
 
 
  -Original Message-
  From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
  Behalf Of Pete Lancashire
  Sent: Monday, May 21, 2012 9:55 PM
  To: Discussion of precise time and frequency measurement
  Subject: [time-nuts] Serial port server .. any interest in a write up
  onusing ?
 
 
  Like many time-nuts I have quite a few devices that communicate to the
  outside world with a serial port. And like many I have more then one. In
 a
  past life I use to have to connect to sometimes a 100 RS232 in one
  location.
  A popular device is called a terminal server or concentrator. They would
  take from 1 to 48 RS232 ports on one side and let you talk to them via an
  Ethernet interface. I so far have twelve RS232 ports in use.
 
  Now that the need for such devices has diminished, these terminal servers
  are showing up, sometimes for pennies.
 
  One brand and model Digi's TS family of models I and have verified they
  work
  with Lady Heather and Trimble Studio on a Windows XP PC.
 
  Digi offers for free a program that makes each RS232 Port look like a COM
  port, and after configuring the terminal server, and this driver, you
 just
  just fire up Lady Heather pointing to the correct COM Port.
 
  Other RS232 ports on the terminal server can either be COM ports, or one
  can
  be connected to via Telnet of for security SSH. For example I have an
  Odetics on one port and I just enter telnet ts4a (the DNS name I gave one
  of
  the terminal
  servers) 2003 (the IP port associated with the third RS232 port).
 
  So if this is of interest to anyone I'll go into more detail, models,
 setup
  etc.
 
  -pete
 
  -pete
 
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Re: [time-nuts] Serial port server .. any interest in a write up on using ?

[Bob Bownes]

I buy them on ebay. Usually $30+SH for 32 ports. 64 port units are harder
to find as are self booting units. (Most xylogics boot from the network,
which is easy enough to make work)




On Tue, May 22, 2012 at 11:46 AM, Chris Albertson albertson.ch...@gmail.com
 wrote:

 Terminal servers are simple boxes.  You just Telnet to the port.  Not
 much you need to know to use one.   But the question is Where to buy
 one cheap?  Is someone on eBay or the like trying to unload a bunch
 of these?

 On Tue, May 22, 2012 at 4:26 AM, Bob Camp li...@rtty.us wrote:
  Hi
 
  I'm interested as well. The USB gizmos are fine for close stuff. They
 aren't quite so nice for gizmos in the attic when the computer is in the
 basement…
 
  Bob
 
  On May 21, 2012, at 10:55 PM, Pete Lancashire wrote:
 
  Like many time-nuts I have quite a few devices that communicate to the
  outside world with a serial port. And like many I have more then one.
  In a past life I use to have to connect to sometimes a 100 RS232 in
  one location. A popular device is called a terminal server or
  concentrator. They would take from 1 to 48 RS232 ports on one side and
  let you talk to them via an Ethernet interface. I so far have twelve
  RS232 ports in use.
 
  Now that the need for such devices has diminished, these terminal
  servers are showing up, sometimes for pennies.
 
  One brand and model Digi's TS family of models I and have verified
  they work with Lady Heather and Trimble Studio on a Windows XP PC.
 
  Digi offers for free a program that makes each RS232 Port look like a
  COM port, and after configuring the terminal server, and this driver,
  you just just fire up Lady Heather pointing to the correct COM Port.
 
  Other RS232 ports on the terminal server can either be COM ports, or
  one can be connected to via Telnet of for security SSH. For example I
  have an Odetics on one port
  and I just enter telnet ts4a (the DNS name I gave one of the terminal
  servers) 2003 (the IP port associated with the third RS232 port).
 
  So if this is of interest to anyone I'll go into more detail, models,
 setup etc.
 
  -pete
 
  -pete
 
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 --

 Chris Albertson
 Redondo Beach, California

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Re: [time-nuts] Chinese Scopes (was: Re: LORAN-C at MIT)

[Bob Bownes]

You know, I have a 1Gig Tek digital (DSA602 with 11A72/11A71,11A34) on my
bench and a 1G Tek analog (7934). The 7934 never gets fired up anymore. I
really should reclaim the space.


On Mon, Apr 16, 2012 at 11:41 AM, Tom Knox act...@hotmail.com wrote:


 I was speaking several years ago to someone at Tektronix and asked why
 they did not still make an analog scope.
 He told me cost was the reason, simply price; to make a modern version of
 the 7104 or 2467B would cost nearly as much as an Italian sports car.
 I have the Latest 40Gs/s scope and it is fantastic but still have a LeCroy
 LA354 analog (of sorts) scope as a second opinion.
 All that said, as someone who brokers equipment, it is difficult to
 justify as a reseller older scopes less the 500MHz in light of the great
 products coming out of China.

 Thomas Knox



  Date: Mon, 16 Apr 2012 08:19:58 -0700
  From: garn...@gmail.com
  To: time-nuts@febo.com
  Subject: Re: [time-nuts] Chinese Scopes (was: Re: LORAN-C at MIT)
 
  I have the latest and greatest from both Tek and Agilent at work,
  designed and made right here in the states. They suffer from menu-itis
  just like the chinese stuff does. My Tek DSA 72004 at work is a
  complete PITA to use unless I have the mouse and keyboard attached. In
  my opinion, it's just how things are in the modern age.
 
 
  -Eric
 
  On Mon, Apr 16, 2012 at 8:03 AM, J. Forster j...@quikus.com wrote:
   I often smile secretly at those who tout the latest asian stuff. It
 may be
   small, light, and look like a 'puter, but it doesn't compare for bench
 use
   to a Tek 7000 series similar vintage portables.
  
   Going through layer after layer of ever more obtuse menus is just not
   'user friendly' to me. Maybe it is to the designers, because they are
 used
   to a 10,000+ character alphabet?
  
   -John
  
   
  
  
  
  
   On Mon, Apr 16, 2012 at 09:46:27AM +0200, Attila Kinali wrote:
  
Sadly, the last scope I bought was a Chinese Rigol. (I do have
 real
scopes too.) It is getting to the point where Rigol and Instek will
   make
buying boat anchors a thing of the past.
  
   What's the quality of those chinese scopes?
  
   I never had the opportunity to use good old Tek, HP or Fluke
 instruments,
   because I never had access to them, so when I begun to buy
 instruments for
   myself, I was completely unbiased and I looked to the price and spec
   sheets
   more than the maker.
  
   To start, I wanted to replace my very very old (but very good) analog
   multimeter, so I bought an handheld Metex digital multimer. I choose
 what
   was
   then their top item with thermocouple and PC connectivity.
   I had soon to give it away for free to a friend (who needed a wire
   continuity
   beeper) and I bought a Fluke 177. It costed me even more, it has not
 PC
   connectivity and thermocouple, but the Metex was completely unuseable
   while the
   Fluke is very good.
  
   Then it was the time for a scope, a function generator and a lab power
   supply.
   I bought all the three from Instek. The scope was the GDS-820S and as
 soon
   as I
   had the opportunity, I sold it and bought an Agilent DSO3062A. This
   Agilent too
   is very entry-level, the plastic case cracks easily, in general the
   quality is
   not near the level the other Agilent instruments I late bought (like
 the
   34401A) but the Instek was unuseable while the Agilent is ok.
   (I still own the function generator and the power supply: being not
   precision
   items they are useable... but for precision I bought an used Wavetek
   generator)
  
   To sum it up, my experience is that good instruments are unvaluable,
 for
   work
   as well for hobby (for hobby it's even more important, because
 it's
   supposed
   you should enjoy doing it!)
  
   Best regards,
   Andrea Baldoni
  
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  --
  --Eric
  _
  Eric Garner
 
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Re: [time-nuts] Best location for a GPS antenna...?

[Bob Bownes]

I do like the optical isolation suggestion. While less than optimal,
perhaps the easiest solution is not to put the isolation between the t'bolt
and the antenna, but to put the isolation between the t'bolt and the
distribution amplifier.

For example, locate the antenna as suggested. Locate the t'bolt in a
suitable enclosure/location either at the building entry or even at the
bottom of the tree. Protect it as well as you can, take best practices for
grounding, etc, but expect to loose one every few years. Maybe put one in
the spares collection. Then take the output of the t'bolt, run through
appropriate electrical to fiber conversion, and feed that to the
distribution amplifier. don't use metal jacketed fiber or metal conduit. A
mistake I have seen made, to great expense.

The issue is that this treats the t'bolt as a sacrificial item. I would
contend that, at a cost of $80-90, you could spend far more time and effort
trying to isolate, amplify, correct, and bias the antenna than that is
worth. Effort and gear that would need to be replaced every time it gets
blown up. My admittedly small direct experience is that lightning arrestors
don't protect from near or direct strikes, just from 'close' strikes.

Just $0.02 from a part of the world that doesn't get zorched nearly as
often. :)

Bob
KI2L

On Wed, Apr 11, 2012 at 8:50 AM, Michael Baker mp...@clanbaker.org wrote:

 Time-Nutters--

 My workshop is surrounded by tall trees (70 to 80 ft).  There
 is no easy way to place my T-Bolt antenna above the tree-top
 foliage.   Since choke-ring antennas do not provide much benefit
 for dealing with multi-path that originates from directly above
 the antenna I have considered putting the antenna on a 10-ft
 pole and mounting the pole in the top of the nearby trees so
 as to have the antenna just above the tree-top foliage.

 However, here in north-central Florida lightning is a serious
 problem.   In the 12 years we have lived here, 3 trees have
 been hit within 75 meters of my workshop building behind
 my house.

 Here is a DropBox link to a map of lightning-strike-days
 in USA locations:
 http://dl.dropbox.com/u/**60102282/Lightning%**20Isokeraunic%20map.JPGhttp://dl.dropbox.com/u/60102282/Lightning%20Isokeraunic%20map.JPG

 I have a number of VHF and UHF antennas mounted on my
 workshop building but when not in use, they are kept
 disconnected where they enter the building.

 I have thought about finding some way to bring the GPS
 RF signal into my workshop via an optical fiber interface
 and sacrifice the RF to optical fiber interface if lightning
 strikes it in a treetop but have not found a way to implement
 this idea.

 Two years ago lightning struck a neighbor's TV antenna
 mounted on a pole attached to the side of his house and
 started a fire in one of their 2nd floor bedrooms which
 did a lot of damage before it was put out.  The tower
 was well grounded and the coax leading into the room
 was fed through a grounded lightning protector but none
 of these precautions prevented the fire from the lightning
 strike.

 Any list folks have ideas on this?

 Mike Baker  WA4HFR
 Gainesville/Micanopy, Fla





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Re: [time-nuts] Best location for a GPS antenna...?

[Bob Bownes]

Don't forget to tighten the fiber connectors and correct for the length of
the fiber or you'll be off by 60ns! ;)


On Wed, Apr 11, 2012 at 1:17 PM, Chris Albertson
albertson.ch...@gmail.comwrote:

 On Wed, Apr 11, 2012 at 7:19 AM, Bob Bownes bow...@gmail.com wrote:

  The issue is that this treats the t'bolt as a sacrificial item. I would
  contend that, at a cost of $80-90, you could spend far more time and
 effort
  trying to isolate, amplify, correct, and bias the antenna than that is
  worth. Effort and gear that would need to be replaced every time

 I thought of that right after I suggested using fiber data lines.
 You'd loose a few expensive t-bolts.But I think there is a better
 and cheaper way to go:   Buy a cheap Motorola Oncore receiver.   The
 Oncore UT costs all of about $18 on eBay, buy four of them.The
 only signal you need to bring into the workroom from an Oncore is PPS
 and that is way easy to do using fiber.   The other signals (rs232)
 can be connected as needed and that is not often.  Then you build a
 standard GSPDO in the workshop.The initial cost is lower and the
 engineering is simple (because only the PPS has to go over fiber)

 The Oncore and GPSDO can give as good of result as the t-bolt.  It
 mostly depends on how good the OCXO is, maybe even you build two
 GPSDOs running off the same PPS the second one being  Rubinium based.
 My $35 Rb can holdover for many weeks (at the level I need) if GPS is
 down.

 Then you can install the t-bolt with an antenna you can disconnect and
 only use the t-bolt now and then during good wearer to double check
 the GPSDO that you can leave running 24x7


 Chris Albertson
 Redondo Beach, California

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Re: [time-nuts] Best location for a GPS antenna...?

[Bob Bownes]

I suspect that would make the multipath problem even worse.

On Wed, Apr 11, 2012 at 4:06 PM, Andrea Baldoni erm1ea...@ermione.comwrote:

 On Wed, Apr 11, 2012 at 10:19:40AM -0400, Bob Bownes wrote:

  I do like the optical isolation suggestion. While less than optimal,
  perhaps the easiest solution is not to put the isolation between the
 t'bolt
  and the antenna, but to put the isolation between the t'bolt and the
  distribution amplifier.

 By the way, would it be possible to retransmit the GPS signal to isolate
 it?

 I mean, rx external antenna - preamp - tx directional internal antenna
 - big
 air gap - rx directional internal antenna - receiver.
 The preamp would not be so power hungry as the full thunderbolt and maybe
 it could be powered via a magnetic link (or a little solar panel with a
 lamp illuminating it).

 Best regards,
 Andrea Baldoni

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Re: [time-nuts] 0MHz distribution...NOT

[Bob Bownes]

What, if any, are the phase changes?


On Mon, Mar 12, 2012 at 5:39 PM, Chuck Forsberg WA7KGX N2469R
c...@omen.comwrote:



 On 03/10/2012 04:44 PM, Mark Spencer wrote:

 I've done this as well.

 I daisy chained several pieces of hp and marconi gear together that all
 had an approx 1k ohm input impedance for the frequency reference and fed
 them from a single 10 Mhz source via t connectors with a 50 ohm terminator
 at the end of the line.   Looking at the signal with either a scope or a
 time interval counter I have seen noticeable phase shifts when some of the
 equipment receiving this signal is turned off or on.   That being said so
 long as the equipment was not turned off or on the adev of the signal was
 as expected.   Your mileage may vary.

 Sent from my iPad

 On 2012-03-10, at 4:24 PM, Michael Blazermbla...@satx.rr.com  wrote:

  You may want to take a look at the signal on a scope.  Most instruments
 terminate their reference input.  You might actually have 4 50 ohm loads on
 the Thunderbolt's output and the input voltage might be marginal.  If your
 instruments have both reference input and output, it's better to daisy
 chain the units.


 On 3/10/2012 5:10 PM, Chuck Forsberg WA7KGX N2469R wrote:

 A month or two ago I had sketched out a simple distribution amp
 for my 10 MHz reference.   In the meantime I became somewhat
 disillusioned about my FE-5680a standards.   So I removed the
 FE-5680a and disconnected its power supply from the box that
 holds the Thunderbolt, power supply, and big line filter.

 I decided to try daisy-chaining the Thunderbolt's 10 MHz output.
 I have plenty of hardware left over from the days of 10BaseT networking.

 So I have the Thunderbolt going to a BNC T on the back of my FlexRadio
 1500,
 hence to my Advantest U3641 spectrum analyzer, and finally to the
 external
 reference on my Racal-Dana 1992 nanosecond universal counter.  That end
 has a 50 ohm termination on the other side of its T connector.

 All three devices seem happy with the 10 MHz they are receiving.

  I connected my Tek 2712 to the end of the chain.  It reads +10dbm
 +-1db.

 Switching units on/off/ext ref causes less than 1db change in the 10 MHz.



 --
 Chuck Forsberg WA7KGX N2469R c...@omen.com   www.omen.com
 Developer of Industrial ZMODEM(Tm) for Embedded Applications
  Omen Technology Inc  The High Reliability Software
 10255 NW Old Cornelius Pass Portland OR 97231   503-614-0430


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[time-nuts] 5061's on ebay

[Bob Bownes]

There are 3 5061's listed on ebay at the moment. Anyone know anything about
them?
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Re: [time-nuts] Low-long-term-drift clock for board level integration?

[Bob Bownes]

Think trying to measure the distance between two distant moving spacecraft
with no idea what the gravitational gradient is between them or the ability
to measure the doppler.

Unless, of course, Bill is doing much different things than he was when I
last ran into him. :)



On Mon, Feb 20, 2012 at 3:32 PM, Hal Murray hmur...@megapathdsl.net wrote:


  You may be able to do a similar thing in your receivers.  For example if
 the
  master node were to send a timing message  at known times (say once at
 the
  top of  every hour) the receivers could use that to determine their local
  clock offset  and rate for those cases where the path was the same (or
 maybe
  even for a list of paths).

 Nope.  The problem is queuing delays in routers.  Satellites don't have
 queues.

 I think those delays is what he is trying to measure.


 --
 These are my opinions, not necessarily my employer's.  I hate spam.




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[time-nuts] Tek to HP conversion... Was: Re: Fwd: FE-5680A Contact FEI

[Bob Bownes]

I was a Tek aficionado for many many years. My first personal scope was a
tek, my first work scope was a Tek. I've owned at least half a dozen over
the decades. The three scopes I own today are Tek. But everything else on
my lab bench has changed over to HP (with the exception of a couple of
TM5006 mainframes full of specialty plugins).

The quality, availability, and most important to me, the consistency of HP
gear has been impressive. I've yet to go into a lab where the majority of
basic RF equipment, counters, sig gens, spectrum analyzers, etc was not HP.
Unless they were lucky enough to have RS.

The ability to get manuals, parts, and just plain guidance on the HP gear
has been great.

Now if I can score an HP Primary or GPSDO standard, I'll be happy.


On Fri, Feb 17, 2012 at 1:26 PM, paul swed paulsw...@gmail.com wrote:

 I believe in HPs case a unique situation occurred on the old gear.
 That is there were and are people at agilent willing to take the time to
 preserve their history. After all its still pretty fantastic stuff even at
 20, 30, and yes I have a piece in the 40-50 years old era. Generally
 amazingly well built. I do know that when test and measurement was HP their
 support was top notch both for me professionally and personally. It did
 effect what I chose to buy for the business. But on the personal side they
 always helped I was above board about why I was calling.
 Ahhh for the good ole days.
 Regards
 Paul
 WB8TSL



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Re: [time-nuts] FE-5680A 1 pps photo

[Bob Bownes]

Just for completeness sake, here is a screen capture off of my DSA-602 of
the 1pps. Note that the trace starts 500ns _before_ the 1pps triggers the
capture. Ah the wonders of digital sampling.


http://www.fastbobs.com/pictures/1pps.jpg

Also as a pdf

http://www.fastbobs.com/pictures/1pps.pdf

Bob


On Thu, Feb 2, 2012 at 1:20 PM, John Howell j...@howell61.f9.co.uk wrote:

 Not odd but my mistake, I took a picture on both 'scopes and the Fluke
 gave marginally better results, the text referred to the wrong one. Sorry
 for the confusion.

 On 2 Feb 2012, at 16:43, David wrote:

  Odd.  Did Tektronix mark it Fluke PM3082? :)
 
  It is nice to know that the current generation of digital cameras can
  be used for this application.  It is too bad that the image has so
  much noise.
 
  On Thu, 2 Feb 2012 16:27:03 +, John Howell j...@howell61.f9.co.uk
  wrote:
 
  and here's another photo of the pulse from one of the newer
 breed of FE-5680A that require the 5V.
  Taken with a Sony Cybershot H5, 8 sec exposure, 'scope is an elderly
 Tektronix 2252
 
  http://dl.dropbox.com/u/1690159/1PPS_1%20FE-5680E.jpg
 
  On 2 Feb 2012, at 15:50, Alberto di Bene wrote:
 
  I managed to take a photo at the scope screen showing the 1 pps pulse
  from an old FE-5680A (the one that does not need the 5V and does not
  output the oscillator signal - just the 1pps).
 
  Exposure was 30 sec, F9. The signal was barely visible with naked eye,
  and some jittering is present. The room of course was in complete
  darkness, but the reflex of the stand-by led of another instrument
  can be seen...
 
  http://dl.dropbox.com/u/15089947/1pps.gif

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Re: [time-nuts] TM 5680-0211 for 5680A series Rubidiums

[Bob Bownes]

If someone sends me the manual, I have a location I can host it.

Bob


On Wed, Feb 1, 2012 at 12:38 PM, Larry McDavid lmcda...@lmceng.com wrote:

 I wish Rob Kimberley's email address had been preserved so I could also
 ask for this manual pdf file without adding traffic to TimeNuts.

 Chris Albertson offered to post the manual on-line to simplify this. I
 hope that is arranged by someone!

 However it be available, I want a copy of the 5680A series Technical
 Manual.

 --
 Best wishes,

 Larry McDavid W6FUB
 Anaheim, CA  (20 miles southeast of Los Angeles, near Disneyland)

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[time-nuts] Determination of the placement of the first pps

[Bob Bownes]

As I am, as Heinlein would say, but an egg in terms of time-nuttery,
perhaps someone could point me toward some history in order to help answer
a question recently posed to me.

At what point was the original global 1pps leading (trailing?) edge
defined/distributed and to what was (is) it referenced? Someone, someplace,
had to give the original time 'hack', no?

I found I could talk about all the wonderfullness of GPSDOs, rubidiums,
ocxo's and the like but couldn't answer that simple question with much more
depth than 'NIST does it for the US' or 'you pull it off of the GPS'.

Thanks,
Bob
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[time-nuts] 5370A on ebay

[Bob Bownes]

if anyone is looking for a 5370, there is one on ebay that is currently
listed for $29+shipping...

http://www.ebay.com/itm/HP-Agilent-5370A-Universal-Time-Interval-Counter-/160714650831?pt=LH_DefaultDomain_0hash=item256b56f4cf

No financial interest, but that's a lot less than I paid for mine! ;)
Probably worth it for the ocxo!

Bob
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Re: [time-nuts] GPS interference and history...

[Bob Bownes]

When you are thinking about replacing GPS receivers, don't forget about
every police car, ambulance, fire truck and most of the tractor trailer's
in the US...The latter don't need timing down to the second, but the first
three use it to well under a minute.

One of the first things you learn when on an ambulance crew is what lump on
the roof to wrap the aluminum foil over when you are going to park the rig
after that run of 5 middle of the night calls and go to sleep. ;)

Some day I'll get the laptops in the rigs to sync up with the GPS directly
rather than using NTP. ;) We probably should be using it to drive the time
code in the video recorders...H.

Bob


On Fri, Jan 13, 2012 at 9:29 AM, Jim Lux jim...@earthlink.net wrote:

 On 6/10/11 7:01 PM, Hal Murray wrote:


 li...@rtty.us said:

 There's an enormous amount of gear out there that gets timing off of GPS.


 That's an interesting claim.  Does anybody have any data on the usage of
 GPS
 for timing?

 I assume there is one in every cell tower and one in every 911 call
 center.
 Are there other large categories of users?



 GPS is pretty ubiquitous as a time source for data loggers in the field,
 things like traffic signals, etc.   There's real value in an inexpensive
 little box that makes sure you don't have to set the clock, even if the
 clock accuracy requirement is something like 1 minute.






 What would it cost to replace all of it?  If you wanted to do something
 like
 that, what would it cover?  How about people like us running old
 recycled
 gear?  (Z3801A, ThunderBolt, ...)


 A fortune, quite literally




 I think I saw one last week.  It was on a river level measuring station on
 the Sacramento River.  It was a small block building.  There was an
 antenna
 pointing up into the sky.  I assume there is a satellite up there.  There
 was
 also a small (~3 inch dia) hemisphere antenna. I assume it was GPS.  (They
 had power going into the building (no solar panels) so it should have been
 simple to get a phone line too.)


 Not necessarily.  And it's not cheap.  Don't forget that you can't run
 power and phone in the same conduit, cable, etc.   So basically you're
 doubling the physical plant installation costs to bring in phone, just for
 the labor to bring it from the nearest point of presence. Especially in
 rural farm kinds of areas, power is more pervaisve than phone (gotta run
 irrigation pumps, etc.)

 Adding a $100-200 GPS receiver (we're not talking GPSDO with OCXO here..)
 is probably cheaper than running ANY length of phone wires: just for the
 termination costs.

 I suppose one could use some sort of GPRS cellular service and get time,
 but then you're on the hook for a monthly subscription fee, etc.


 cheap L1 only GPS is a great solution.  Apply power, wait, you've got
 accurate time.  No need to have someone visit periodically and check to see
 if the clock needs to be reset, etc.






 I'm not sure why they need GPS at the recording house.  They know where
 it is
 so timing is the only use I can think of.  But they could also get that at
 the receiving end.  Millisecond accuracy isn't helpful.  Second level
 accuracy might be interesting if something breaks and you want to know
 when
 the wave got to downstream stations.  The risetime is probably over a
 second.


  You're right, they don't need milliseconds, nor do they need seconds,
 probably.

 There's really no other convenient way to get time to the nearest minute
 that is as reliable and cheap as GPS. Think about it... WWVB? WWV? Vertical
 pointing sun sensor?




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