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  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  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  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  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  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]

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  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  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  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  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  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  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  wrote:
> 
>> On Mon, Oct 23, 2017 at 1:49 PM, Bob Bownes  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 Ohm coax, frequency
> > > reference signals to my test e

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;">
> 
> https://www.avast.com/sig-email?utm_medium=email&;
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> 
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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 
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  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  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"  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  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  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"  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  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
>>>> ___
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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
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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&si=8bBNGShIPf%252FvJpucfMDlEGXDrwI%253D&orig_cvip=true&rt=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  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 
> To: Discussion of precise time and frequency measurement  
> 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  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  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  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.
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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] Is there any Ubuntu/Linux Software for the Z3801A?

[bownes]

Walter,

You can always download VirtualBox and run a Windows system in there under 
Linux, OS X, Solaris, or whatever you like. It's free, and it works well. 

Oracle VM works too, but is probably overkill. 

Bob

> On Dec 1, 2016, at 13:07, walter shawlee 2  wrote:
> 
> After re-working the lab I have my Z3801A in, I realized there's no windows
> computers left anywhere near there.  Is there any monitoring software that 
> will run on my 16.04 Ubuntu Linux machines?  I have the Z3801A with an 
> external antenna, that drives a 10Mhz distribution amp for optional external 
> references around the lab. I don't have anything looking at it, however, so I 
> am not sure if that is actually correcting the GPSDO or I am seeing the raw 
> oscillator, which si pretty good by itself.  The other shop counters have 
> externally NIST-cal'd hp 10811A's in them, so they are pretty accurate 
> anyway, but I am curious to know the real story.
> 
> I also have a re-cycled rubidium module and ovenized oscillator cal'd to NIST 
> in tandem as another check source I put together this year.  I'm just looking 
> for external validation of those last few figures. I guess that is an 
> occupational problem of having too many sources and counters, one is never 
> really totally certain. kind of a local quantum cloud of measurement 
> uncertainty.
> 
> I was able to get those surplus DeLorme GPS pucks running under Ubuntu, I ran 
> VMware to host an XP install, then tracked down the XP-only serial emulator 
> needed to read the USB puck interface, and ta-da, it works. Hideously 
> complicated way to see if they were good, but I was curious to know.  No 
> VMware in that lab, however, so looking for a native app to read the Z3801A
> 
> any useful Z3801A software suggestions appreciated,
> all the best,
> walter
> 
> -- 
> Walter Shawlee 2, President
> Sphere Research Corporation
> 3394 Sunnyside Rd.,  West Kelowna,  BC
> V1Z 2V4  CANADA  Phone: (250) 769-1834
> walt...@sphere.bc.ca
> WS2: We're all in one boat, no matter how it looks to you.
> Love is all you need. (John Lennon)
> But, that doesn't mean other things don't come in handy. (WS2)
> 
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Re: [time-nuts] RPi/ beagle bone-like computer without video

[bownes]

Fits very nicely into a 5370 in fact. :)

> On Nov 30, 2016, at 17:12, Graham / KE9H  wrote:
> 
> The BeagleBone Green is a BeagleBone Black with the HDMI and video chip
> removed.
> 
> Mouser Part number *Mouser Part #: *713-102010027, $39, In stock.
> 
> 
> Makes a great little headless server.
> 
> --- Graham
> 
> ==
> 
>> On Wed, Nov 30, 2016 at 3:51 PM, Clint Jay  wrote:
>> 
>> Raspberry Pi compute module? Maybe even a Pi Zero?
>> 
>>> On 30 Nov 2016 21:47, "Adrian Godwin"  wrote:
>>> 
>>> The tiny g3 routers are worth looking at. They have WiFi, Ethernet and
>> USB,
>>> cost very little and will usually run wrt54g Linux. Can be rather short
>> on
>>> memory though.
>>> 
 On 30 Nov 2016 8:43 p.m., "jimlux"  wrote:
 
 I'm looking for a small linux single board - similar to RPi or
>> Beaglebone
 Black, but don't need the HDMI, or video stuff.
 Preferably without weird connectors, and available for wide temperature
 ranges (it's for a data logger/collector in the field)
 
 What's out there?
 
 There's BBB in industrial flavor (-40 to +85C ) for $60-70
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Re: [time-nuts] Linux PPS clues?

[bownes]

I suspect the multitasking aspect of the OS will give you far more jitter than 
one could cope with. 

> On Nov 4, 2016, at 22:46, Casey L. Jones  wrote:
> 
> Maybe you could use something like a serial to parallel converter chip or the 
> serial port input of a microcontroller. You could feed in a constant string 
> of zeros until an event, and then feed in a one to the stream when the event 
> occurs. You could save the stream of ones and zeros in memory for maybe a 
> second, and then stamp the block with the time. Then you can have your main 
> CPU figure out the time of each event by knowing the bitrate and looking at 
> how many bits precede each one bit back to the beginning of the block. The 
> blocks would likely be largely zeros, and would thus compress really well if 
> you decide to not even bother converting the format of the blocks to a 
> timestamp format. The advantage of this scheme is that it could probably have 
> a sampling rate far higher than a timestamping process, without overstressing 
> even many modestly powered processors.
> 
> Another way to synchronize your samples with GPS, at the cost of some sample 
> rate, is to use a two input multiplexer at your serial input and to take 
> every odd bit of your serial stream to be a sample of the pps output of your 
> GPS and every even bit to be the state of your event trigger. That way your 
> pps and data are interleaved in your bitstream for post processing.
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Re: [time-nuts] Thinking outside the box a super reference

[bownes]

Not to mention there is not so sensitive film, sensitive film and really 
sensitive film. 

Good old orthographic film took minutes in bright light. 



> On Nov 4, 2016, at 20:24, Poul-Henning Kamp  wrote:
> 
> 
> In message , David writes:
> 
>> Various online sources say that natural rubidium is radioactive enough
>> to fog photographic film in 1 to 2 months but that is also the case
>> with unprocessed uranium ore so I would not worry about it at all.
> 
> Yes, that sounds about right for an isotope with a 40 billion years
> half-life.
> 
> 1 to 2 months is a LNG time for photographic film.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
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[time-nuts] IRIG-B for OS X

[bownes]

Has anyone seen an IRIG-B generator for OS X sound port?

I know there is one for the PC in NTP, but thought I would ask before diving in 
to that asp pit. 

Bob
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Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

[bownes]

Just shipped out three new systems for $DAY_JOB to Goldstone, Madrid and 
Canberra. 

Love it when work and time nuts intersect. 



> On Sep 13, 2016, at 17:35, Andy ZL3AG  wrote:
> 
> 
> That sounds like fun!
> 
> Do they have a mailing list they hang out on?
> 
> https://eyes.nasa.gov/dsn/dsn.html
> 
> 
> 
>> On 14/09/2016, at 5:04 AM, Mike Baker wrote:
>> 
>> Hello, Time-Nutters--
>> 
>> Full disclosure--  I am a complete newbie at understanding the
>> intricacies of generating a really stable, low phase noise, accurate
>> frequency reference for microwave reception up around the 8 GHz
>> DSN (Deep Space Network) band.  I have been following the back
>> and forth comments on the Time-Nuts list about improving the
>> Trimble T-bolt's 10 MHz output but confess that most of it is pretty
>> much deeper technical voo-doo than I am comfortable with.
> 
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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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Re: [time-nuts] DIY VNA design

[bownes]

Comment inline


> On Aug 21, 2016, at 18:59, Dr. David Kirkby (Kirkby Microwave Ltd) 
>  wrote:
> 
> I am not convinced that this is time-nuts related,  although I am sure many
> time-nuts either have a VNA or would like one. Such a project needs its own
> forum.
> 

v...@yahoogroups.com would be the place. 

The intersection of HP equipment && Time-Nuts && VNWA mailing lists is >> 1 :)

> 
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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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Re: [time-nuts] Shera revisted

[bownes]

There are also some nice cypresses semiconductor parts that are similar and 
have a really nice dev environment. 
Basically a core surrounded by programmable logic. Code in C ore close to it. 



> On Aug 11, 2016, at 07:06, Bob Camp  wrote:
> 
> Hi
> 
> To your earlier point, there are a number of fairly low cost boards with 
> Zynq’s on them. 
> They aren’t into the $5 range, but they are not that much more than one of 
> the Beagle 
> boards. 
> 
> Bob
> 
> 
>> On Aug 10, 2016, at 11:18 PM, Chris Albertson  
>> wrote:
>> 
>> Thanks for pointing out the Zynq.  Wow you get a dual core ARM and an
>> FPGA all in one package.   It seems overkill for a GPSDO but not the
>> type you are making as you can transferring the time out of the GPSDO
>> using PTP.
>> 
>> The Zyng looks to the the perfect platform for low-cost SDR.
>> 
>> On Wed, Aug 10, 2016 at 2:30 PM, Joakim Langlet
>>  wrote:
>>> Dear time-nuts,
>>> 
>>> My name is Joakim Langlet (SM0OET) and I just recently joined this list. As
>>> Brooks Shera was mentioned, I remembered that I was referenced in the
>>> footnotes of the original article in the QST - July 1998. It feels almost
>>> historical now. Brooks bought a few OCXOs from me.
>>> 
>>> I am currently working on a GPS stabilized OCXO.
>>> It is based on a Xilinx Zynq FPGA as the processor and counter arrangement.
>>> The hardware is starting to take shape. The control voltage of a 20 MHz OCXO
>>> is set by a DAC coupling from which I hope to set the voltage in very small
>>> steps.
>>> The OCXO has a CMOS level output which is converted to LVDS and is wired to
>>> the FPGA board. The Xilinx Zynq take a minimum frequency of 19 MHz as input
>>> to the PLL of the clock tile. My intention is to scale up the clock to some
>>> where a bit over 200 MHz to be fed to the counters.The 1 PPS from the GPS
>>> receiver is also fed into the FPGA to gate the counters.
>>> 
>>> The reason for my choice of processor is that I want to run Linux on it in
>>> order benefit from the large software base. Time distribution using PTPv2
>>> and a nice web-application to visualize and control what is going on inside
>>> is part of the intended concept.
>>> 
>>> I still have a long way to the finish line but I will try to present some
>>> results as I proceed.
>>> 
>>> I am following what is written on this list with great interest. It feels
>>> good to know that I am not the only nut 
>>> 
>>> BR/
>>> Joakim
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>>> and follow the instructions there.
>> 
>> 
>> 
>> -- 
>> 
>> Chris Albertson
>> Redondo Beach, California
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Re: [time-nuts] [LEAPSECS] Leap second to be introduced at midnight UTC December 31 this year

[bownes]

We've been dealing with speed of light issues for over 20 years in the 
financial world. And telecom. 

Someone recently built a new fiber route from Chicago to NY because it was just 
a touch shorter. The distances are down to hundredths of a ms. 

> On Jul 25, 2016, at 17:41, Bob Camp  wrote:
> 
> Hi
> 
> In these days of computers trading with computers, the whole issue of “who 
> did what when” can 
> result in major money trading hands. I’m sure that at some point the 
> financial markets will have to
> deal with light speed issues and geography if they have not already.  
> 
> Bob
> 
>> On Jul 25, 2016, at 4:57 PM, Mark Sims  wrote:
>> 
>> Apple's new file system timestamps files with nanosecond resolution.   A lot 
>> of Linux file systems also do that now.   The nanosecond ain't what it used 
>> to be...  I can imagine people wanting picosecond timestamps in the near 
>> future.  Who knows,  maybe we'll have something like NTP compensating for 
>> light-speed delay for the gap between the read/write heads and disk surface 
>> (assuming we still use heads and surfaces)  ; -)
>> 
>> Except that you still have the issue of “what time did this file get 
>> changed”. To most of us, that’s not really a big deal. A second either way … 
>> who cares. 
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Re: [time-nuts] [LEAPSECS] Leap second to be introduced at midnight UTC December 31 this year

[bownes]

A second here or there is a very big deal to those of us in the financial and 
database worlds. 

Aside from the well known instances involving electronic trading I have 
customers fighting over cabinet positions and cable lengths to place processors 
closer to disk drives and on switch paths with 10ns less latency. 





> On Jul 25, 2016, at 16:57, Mark Sims  wrote:
> 
> Apple's new file system timestamps files with nanosecond resolution.   A lot 
> of Linux file systems also do that now.   The nanosecond ain't what it used 
> to be...  I can imagine people wanting picosecond timestamps in the near 
> future.  Who knows,  maybe we'll have something like NTP compensating for 
> light-speed delay for the gap between the read/write heads and disk surface 
> (assuming we still use heads and surfaces)  ; -)
> 
> Except that you still have the issue of “what time did this file get 
> changed”. To most of us, that’s not really a big deal. A second either way … 
> who cares.   
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Re: [time-nuts] The home time-lab

[bownes]

Or the current version:

Large AC motor driving a LARGE flywheel with an AC (and/or -48VDC) generator on 
the other side feeding a very large battery plant. If mains drops more than 1/2 
cycle it connects the turbine and starts it up. 

We had a 5MW one at $OLD_GIG for feeding our supercomputer factory. 

It was rumored that at least one customer location kept one of their turbines 
(redundant) idling at all times because they could not afford to loose a data 
set. 



> On Jul 25, 2016, at 09:55, Bob Camp  wrote:
> 
> Hi
> 
> If you go back far enough in time …. there is another alternative:
> 
>   Big rectifier bank, turning AC into DC, often off of multiple phases or 
> sources. 
> 
>   Big DC motor running into a fairly large flywheel. 
> 
>   AC generator (or in some cases DC generators) running off of the shaft
> 
>   A tuning fork (yes state of the art timing) based control on the AC 
> output frequency  
> 
>   A saturated reactor control loop on the generator side, same thing on 
> the motor side.
> 
> Wonderfull stuff. State of the art UPS for your shipboard computer in 1962. 
> Ear muffs anyone? 
> 
> Bob
> 
> 
> 
>> On Jul 25, 2016, at 8:39 AM, Charles Steinmetz  wrote:
>> 
>> Chris wrote:
>> 
>>> I've never thought UPS were a good idea for anything but a computer
>>> that needs to shut down gracefully.   For your use you need something
>>> that cleans up the AC mains power.
>> 
>> A proper "online" (or "double conversion") UPS does just that.  It always 
>> provides cleanly-generated sine-wave power from a DC-AC converter.  Most 
>> will even deliver crystal-controlled power (i.e., non-synchronous with the 
>> AC line) in several frequency increments, if you desire, as well as a choice 
>> of regulated output voltages.  (For obvious reasons, they are usually 
>> operated synchronously.)
>> 
>> They are *much* more effective than ferroresonant supplies at removing 
>> glitches from the mains supply.
>> 
>> You must be referring to "offline" backup supplies.
>> 
>> Best regards,
>> 
>> Charles
>> 
>> 
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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] Good GPSDO on eBay?

[bownes]

To paraphrase a few other folks, taking on the task of building your own, even 
using the VE2ZAZ board as a basis is a very educational experience. It will 
teach you an enormous amount. There are lessons in control systems, phase and 
frequency locked loops, oven controllers, phase and frequency measurement, and 
doubtless lots of things I've overlooked. 

Well worth the effort. 

> On Jul 9, 2016, at 23:06, Bob Stewart  wrote:
> 
> But, as a starter GPSDO, probably anything is good.  Frequency accuracy, even 
> if a fraction of a Hz off, is all you're looking for at first.  I bought one 
> of Bert Zauhar's (VE2ZAZ) circuit boards and chips for my first one.  It was 
> a good experience.  And when I was done, I had a GPSDO that was as good as 
> most of what you find on ebay in the bargain basement, but at a much lower 
> cost.  But then you need a case, and something to compare it to, and 
> something even better, and then you're a time-nut.
> 
> But 
> 
> 
> At 04:40 PM 7/9/2016, Richard Mogford wrote:
>> This looks like a good beginner's GPSDO on eBay: 172148560746
>> 
>> "This is GPS Disciplined Clock made with trimble GPSDO Board.Full 
>> tested by Agilent 53132A with US-012 option and Ex-ref from trimble 
>> thunderbolt GPSDO."
>> 
>> 
>>   The seller says it has a sine wave output and is accurate from
>>   10e-11 to 10e-12.
>> 
>> Any thoughts?
>> 
>> Richard
>> 
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Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)

[bownes]

And try to tell transistor A from transistor B from diode C when they are all 
upside down. 

A moving head design can be made to pick up parts off of reels on all four 
sides. But it takes more table space. Which is money. 

As someone else said, you need Z rotation, which isn't as easy as it sounds 
when using pneumatics to pick up the part. 

Moving table design sounds like a recipe for shaking the parts off the solder 
pads. I've not had good luck with solder paste staying tacky for long. In which 
case you are dispensing paste then sticking part. Not a deal breaker but slow. 

> On Jun 25, 2016, at 04:12, Adrian Godwin  wrote:
> 
> Many parts can't be recognised visually. Capacitors are the obvious example.
> 
> On Sat, Jun 25, 2016 at 6:11 AM, Chris Albertson 
> wrote:
> 
>> The ideal hobby use pick and place machine would be very different
>> from a commercial machine.  Lets say I want one board made.   What I
>> want to minimize is my time.  With a conventional machine by FAR most
>> of my time is spent setting the machine up.  In fact setup is so slow
>> that for smaller PCBs I could do it with tweezers in a fifth of the
>> time needed to set up the machine.
>> 
>> So a hobby machine must be designed such that you could get it going
>> in nearly zero time.   In the ideal case you drop the parts all mixed
>> up, (but right side up) in a small tray.  They are mixed and in random
>> orientation.  then you give the machine your PCB design file (not a
>> special pick and place file) and then a vision system IDs the parts.
>> Today vision is dirt cheap.
>> 
>> But the 3D printer needs one more degree of freedom.  It must be able
>> to rotate the part (or the PCB) as it is unlikely the part on the tape
>> or tray only needs translation to the PCB, likely ration is required
>> in almost all cases.
>> 
>> I think a hobby machine would only be successful if it could reduce
>> the setup time to nearly zero and for that it would need a really good
>> vision system that could hunt down randomly placed parts.  It would
>> have to work pretty much like you or I would do the job manually.  But
>> we have software like openCV and good "board cams" with M7
>> interchangeable lenses for $35.  A vision system actually saves a ton
>> of money because the machine need not be so precise as vision closes a
>> feedback loop.
>> 
>> Also how many hobbyists are going to have reels of parts?  I might buy
>> some parts by the dozen but most no more than about 4 or 6 at a time.
>> I don't want a large machine.  It should have a working surface, a
>> white melamine table about 12 inches square and I place the PCB to be
>> stuffed and all the parts on the same foot square table at any random
>> location then press the "go" button.  The camera scans the table.
>> This kind of machine would be horrible for production work but a one
>> foot cube machine that required zero setup is what most of us want.
>> 
>> Going a little farther.  I'd like this SAME machine to actually make
>> the PCB too.  A 3D printer could route the copper and drill holes and
>> print the solder resist plastic too.
>> 
>>> On Fri, Jun 24, 2016 at 8:56 PM, Attila Kinali  wrote:
>>> On Fri, 24 Jun 2016 13:59:58 -0500
>>> "Graham / KE9H"  wrote:
>>> 
 Lots of problems to be solved...
>>> 
>>> Most of these problems are easy:
>>> 
 How do you take loose parts or cut tape or tape reels
>>> 
>>> You don't. No loose parts with any kind of pick&place machine.
>>> As for cut tape, these can be taped on an empty reel to make
>>> them compatible. Everything has to be in a tray, reel or similar.
>>> 
 and get the right
 part out, and into the chuck, oriented in the right direction?
>>> 
>>> Orientation is defined by the reel/tray the parts come in.
>>> This is also documented in the datasheet, usually.
>>> 
 How many different kinds of parts, sizes, shapes, pin counts, IC
 footprints, can you handle at once?
>>> 
>>> As many as there is space around the machine :-)
>>> 
 How do you know it is the correct part?
>>> 
>>> You put it manually in the right feeder and double check that it
>>> fits the programming.
>>> 
 How do you know where the "+" end, or "pin 1" is?
>>> 
>>> This comes with the orientation of the part in the reel/tray.
>>> 
 How do you know that there actually is a part in the chuck?
>>> 
>>> Your trays are guaranteed to be non-empty by manually loading them.
>>> 
 How do you know the part in the chuck is oriented the way you expected
>> it?
>>> 
>>> The manufacturer guarantees that the reels/trays are loaded correctly.
>>> 
 How do you know where the footprint on the circuit board is located?
>> (to a
 few thousandths.)
>>> 
>>> This is provided by the pick&place file. Usually its 3-5 digits after the
>>> decimal point, when using mm. But as I wrote before, you don't have to
>>> place part hyper exact. Being within 0.1-0.3 of the pitch of the part
>>> is usually enough. Surface tension does the rest.
>>> 
>>>

Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping

[bownes]

Aside from using the toaster oven reflow controller from SparkFun? 

> On Jun 23, 2016, at 21:28, Jay Grizzard  wrote:
> 
>> On Thu, Jun 23, 2016 at 11:28:00PM +, Mark Sims wrote:
>> A usable re-flow oven can be had for $300.
> 
> Do you (or anyone) have suggestions for usable reflow ovens in this price
> range? Every time I've gone looking on Amazon, I've found ovens which
> (according to reviews) had cycle timers were *horribly* off, to the point
> they would sometimes burn boards by keeping them at peak temperature 
> for 2x - 3x as long as they were programmed to. Though you can work
> around that if you really want to, this really doesn't meet my definition
> of "usable".
> 
> Am I missing some obvious cheapie oven without these types of problems?
> 
> -j
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[time-nuts] HP 4352A

[bownes]

I just asked over on the HP equipment list, but time nuts had a thread on the 
4352 a while back...

 Has anyone got a service manual for the  4352A? The B version is out there in 
the wild, but the A version seems to have gone MIA. 

Additionally, should anyone have either a 11636B power divider or 8471e#004 
peak detector surplus to their needs, please let me know as the 4352A I got 
last week is missing both. 

There are, however, three more left on eBay from a vendor outside LA. They are 
all missing the power divider and peak detector however. But for $130, I 
figured it was worth a gamble. 

I suspect that any power divider good to 4GHz and peak detector good to the 
same can be made to work pretty well though. If I can't find the peak detector, 
 I may try substituting a linear power detector since I have a drawer full. 

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[time-nuts] Datum 105242-001 pinout

[bownes]

My Google fu is weak tonight. 

I'm out in the field getting ready for the ARRL VHF/UHF contest. Thought I'd 
bring along the bits for my 10GHz transverter and assemble it during the 
downtime. 

But I'm being thwarted. 

Does anyone have the pinout for  the six pin Datum 10Mhz oscillators?

Thanks! 
Bob
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[time-nuts] MIT Flea & HP 5328

[bownes]

Apologies to those not in or around Boston tomorrow. You can ignore this msg. 

I'll be at the flea tomorrow selling off a 5328 with 10811 OXCO & 15GHz 
prescaler and a few other goodies.

I seem to recall that there are generally a few of us in attendance. Perhaps we 
could have an impromptu gathering of time nuts at say, 11 AM? 

Bob
KI2L
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Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

[bownes]

N connectors should never need to 'lubed'. Properly assembled they are 
waterproof. Same goes for BNC. That's what the rubber gasket on the mating 
surface is for. Metrology grade Ns don't have the gasket but you shouldn't need 
it on your metrology bench. :)

That being said, it never hurts to wrapped up with coax seal tape. 

> On Apr 20, 2016, at 21:03, Ryan Stasel  wrote:
> 
> Bob/Paul,
> 
> Thanks. And there's the rub... Who knows what the specs are on "generic" RG6 
> QS. I'll see what my seller wants for their LMR400, but otherwise yeah, RG6 
> is just easier. I have both compression and crimp connectors for it, 
> including some RG6 N-connectors (yeah, they're probably for LMR300, but they 
> work). 
> 
> Other question: any tips for the exterior N connection? I can "weatherproof" 
> the actual cable-connector crimp, but I'm curious if anyone bothers to "lube" 
> the N connector to keep moisture from otherwise seizing it up. 
> 
> Thanks!
> 
> Ryan Stasel
> IT Operations Manager, SOJC
> University of Oregon
> 
> Sent from my iPhone
> 
>> On Apr 20, 2016, at 17:00, Bob Camp  wrote:
>> 
>> Hi
>> 
>> RG-6 Quad Shield should be fine as long as it’s meeting the published specs. 
>> The advantage of LRM-400 is that you likely *know* where it came from and 
>> what the specs are. 
>> 
>> If you decide to split the antenna between GPSDO’s, a powered splitter is a 
>> really good idea. Each time you split another 2 ways, you loose 3 db. Get at 
>> least a 4 way splitter ….
>> 
>> Bob
>> 
>>> On Apr 20, 2016, at 4:41 PM, Ryan Stasel  wrote:
>>> 
>>> All, 
>>> 
>>> I’m going to be installing a “permanent” antenna at home, and will need a 
>>> run of about 100ft to get from my workstation, to the mast I’ll be mounting 
>>> the antenna on (Symmetricom 58532A). I’ve seen some indication that both 
>>> the antenna and the Trimble Thunderbolt won’t have any issues with running 
>>> over 75ohm cable, but thought I’d ask the “experts” whether I’d be better 
>>> off with some RG6 Quad-shield, or LMR400 (I’ve got a local source that 
>>> doesn’t know what LMR400 is, or what it’s worth)? 
>>> 
>>> Obviously I’d prefer to run and crimp RG6, but if I’d be better off with 
>>> LMR400, I’d rather run that now than go back into the crawlspace again. =)
>>> 
>>> Also, if it helps, I’ll probably have a Symmetricom/HP 58516A at/near the 
>>> T-bolt so I can experiment with other GPS(DO)s as well (especially one of 
>>> the JRMiller boards I bought and built (but never finished) ages ago). 
>>> Which brings the question, will the T-bolt provide the oomph needed to 
>>> power that splitter and the antenna over that length of cable? 
>>> 
>>> Thanks! 
>>> 
>>> -Ryan Stasel
>>> 
>>> 
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Re: [time-nuts] Fast risetime pulse generator

[bownes]

Maybe a krytron? If you are able to get one anyway. ;)

> On Apr 13, 2016, at 18:32, David  wrote:
> 
>> On Wed, 13 Apr 2016 00:03:03 -0500, you wrote:
>> 
>> ...
>> 
>> If you are building up something, you probably want a SRD (step
>> recovery diode) or tunnel diode. But both may be hard to find and
>> expensive these days.
> 
> Step recovery diodes are very similar in construction to varactor
> diodes so the later can be used in step recovery applications with
> qualification.
> 
> I have also seen the 1N4148 used as a step recovery diode when driven
> by an avalanche pulser but I do not know if it was qualified.
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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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Re: [time-nuts] HP 5372A advice

[bownes]

Has anyone published a summary of the differences between the '71 & '72?


> On Jan 20, 2016, at 15:11, Poul-Henning Kamp  wrote:
> 
> 
> In message <569fde69.2020...@rubidium.dyndns.org>, Magnus Danielson writes:
> 
>> Good, then I have not remembered completely wrong.
> 
> The 5371 and 5373 manuals are not without relevance either, and
> don't overlook the app-notes and the HPJ (1989-02) articles either.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] New Member + Basic Questions

[bownes]

The 8640 will lock to an external 5Mhz reference. That's what the BNC in the 
heatsink is for. At least that is where it is on mine. 

The trick is doing a good divide by two. 

However, that said, the 8640 tops out at ~1024MHz, which if you get interested 
in even the lower microwaves, is not quite enough. 



Bob
KI2L

> On Jan 11, 2016, at 09:47, Rob Sherwood.  wrote:
> 
> The HP 8647A may be the worst signal generator HP ever made.  The 8656B won't 
> even go down low enough in level to make a noise floor measurement on a 
> modern transceiver.  Sure you can add external attenuation, but you won't 
> know about how much leakage is occurring.  Otherwise why wouldn't HP have 
> added another 15 dB attenuation in the box? That is why I mentioned the 
> 8657B.  Yes the 8662A's reliability issue is the power supply.  No question 
> not a starter generator.  The 8642A was never intended for field repair, but 
> it is the only generator with low enough phase noise to test top radios 
> today, and something a ham could afford. Again, not the first sig gen that 
> should be on your list 
> 
> Rob, NC0B
> Sent from my iPad
> 
>> On Jan 11, 2016, at 8:01 AM, "Nathan Johnson"  wrote:
>> 
>> 
>> 
>> I really appreciate all the help. I really like that Ref0 combination, I 
>> don't
>> see any Ref1s available right now, but you are saying that any decent
>> GPS+Arduino can substitute? Should I be looking in the archives for that, or 
>> is
>> there a website?
>> Minor clarification to my earlier post about the signal gen, I am aware that 
>> the
>> 8640 won't lock to an external reference. I had intended that to read
>> 8640-something or 50-something. I'm watching an 8647 and an 8656b on the 
>> usual
>> site at the moment. That 8662 looks beautiful, but it's a huge investment 
>> for a
>> piece of old gear that has a reputation for being a bit... Cranky and
>> opinionated. I have no practical need for that now, so I won't sign up for 
>> that
>> kind of challenge until I do.
>> I'm quite familiar with how this stuff multiplies, I have a Tektronix scope
>> collection, and have been a lurker on the TekScopes list for about a year. 
>> There
>> is a running joke on that list about "scope acquisition disorder". I'm pretty
>> sure that I'm infected, but I only have 5 scopes in the house at the moment, 
>> so
>> it's not that bad... Yet!
>> 
>> Nathan KK4REY
>> Sent using CloudMagic Email
>> [https://cloudmagic.com/k/d/mailapp?ct=pi&cv=7.4.15&pv=9.1&source=email_footer_2]
>> On Mon, Jan 11, 2016 at 04:28, Discussion of precise time and frequency
>> measurement  wrote:
>> Good thread everyone.
>> Nathan you have received a lot of wisdom and humor today.
>> Yes for sub $200 you can be in good shape.
>> If lucent remember a Ref0 needs an arduino and a good GPS 1 PPS.
>> Though frankly even neo6s play well.
>> If a Ref1 it has a GPS in and no need for the arduino. The $175 gets you a
>> ref1 and ref0 combo that tie together usually with a cable thats shipped
>> with the units.
>> Mine were brand spanking new. NOS.
>> Good luck.
>> To Ron o yes no shed or anything but the gear builds up. Darn thing is
>> this stuff actually last longer then an iPhone99X due out tomorrow I am
>> sure.
>> Paul
>> WB8TSL
>> 
>>> On Sun, Jan 10, 2016 at 4:31 PM, Rob Sherwood.  wrote:
>>> 
>>> Paul,
>>> 
>>> Your last paragraph was a hoot. A ham friend of mine recently rented a
>>> storage shed to keep all his spare test equipment and parts units. Another
>>> ham friend used to have four storage units to store all his "stuff". The
>>> disease is not curable with either time or antibiotics.
>>> 
>>> My XYL will have to deal with two homes with labs and ham shacks, 7
>>> towers, 13 yagis, etc. when I am SK. Need I say more.
>>> 
>>> Rob
>>> NC0B
>>> 
>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed
>>> Sent: Sunday, January 10, 2016 1:56 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] New Member + Basic Questions
>>> 
>>> 
>>> 
>>> Nathan,
>>> Bob shared a link for the Lucent units and a great amount of detail has
>>> been shared on Time-nuts about them. They will do what you want. The Ref0
>>> requires a external GPS receiver and another Time-Nuts Arduino. It works
>>> really well and the quality of the ref0 seems to be that of the 1pps
>>> feeding it.
>>> But they also make a no brainer pair that has a ref0 and ref1 that has a
>>> built in GPS receiver. They were $175 but they go all over the place in
>>> price. But it does just work.
>>> Trace-ability is an interesting word around this group. From your
>>> description not sure thats really a need. Accept for the oven oscillator
>>> they all are great and yes even really good oven oscillators are great and
>>> can actually be amazing. Not cheap at all though.
>>> You describe your counter and sig gen they have a resolution of .1Hz so
>>> going further isn't really all that helpful.
>>> Now

[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] How did they distribute time in the old days?

[bownes]

And to tie this back to the UPS thread, at university, the Simplex clock sync 
signal made our Vax 11/730 TOD clock run wy fast. 
I never figured out if it was using line frequency zero crossings for seconds 
or if it was leaking as DEC fixed it not long after it was installed. (And it 
was moved to a different phase of the power system than the clocks...)



> On Oct 14, 2015, at 15:55, Jim Harman  wrote:
> 
> The Western Union clocks were still in use at broadcast stations in the
> early 1970s. One problem was that the reset pulse and resulting jump in
> time would come exactly on the hour, when you were trying to synchronize
> with a network news broadcast that began at the network's version of 00:00.
> 
> ABC and I presume the other networks would send a tone 10 seconds before
> their program started, By listening to the network on the "Cue" channel,
> you would have a pretty good idea of when the news would start.
> 
> Another system in wide use around then and still somewhat today for
> controlling the clocks in a large building was sold by Simplex. The
> building would have a master clock (set manually by the custodian or
> whoever) that pumped out tones at about 3 KHz over the power lines. These
> signals would come out a couple of minutes before the hour, presumably to
> avoid problems with events scheduled on the hour. The slave clocks were
> designed to run a little fast, and would wait at 58:00 until they received
> a tone to restart. I believe there was a special tone that would make the
> clock run "fast forward," to deal with longer adjustments for power outages
> and DST.
> 
> One drawback of this system is that the tones sometimes leak into audio
> equipment, and in a quiet room they are often audible through the
> fluorescent light ballasts.
> 
> On Wed, Oct 14, 2015 at 12:42 PM, Nick Sayer via time-nuts <
> time-nuts@febo.com> wrote:
> 
>> 
>> 
>> 
>> The WU standard time service goes back further than the turn of the 20th
>> century. It started in 1870.
>> 
>> --
> 
> --Jim Harman
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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] Thunderbolt/Arduino RS232 Interface Issue

[bownes]

Swap the tx and rx lines on the Arduino. Swap back to reconnect to PC. 



> On Jun 3, 2015, at 10:51, Chris Albertson  wrote:
> 
> In the RS-232 world devices are either DTE or DCE.  You need one of
> each on each end of the line if using a normal straight cable.To
> connect two like devices you need a crossover cable (AKA "null modem")
>From the sounds of it I'm guessing the PC is a DCE and the Arduino
> and Thunderbolt are both DTE.
> 
>> On Tue, Jun 2, 2015 at 9:38 PM, Dan Quigley  wrote:
>> Hello,
>> 
>> I'm integrating an Arduino (Due/Mega have tried both) with a surplus 
>> Thunderbolt and need some advice.
>> 
>> The Thunderbolt is a known working unit (supplies 10Mhz to my HPSDR rig) and 
>> the serial interface works fine between it and a PC.  I've read the coverage 
>> about this kind of integration (and some of the archived discussions on this 
>> board) and am employing a commercially available MAX232-based "shield" 
>> (RS232 V2) to handle the level translations.  Just three lines (RX/TX/GND) 
>> are  used.  The MAX232 circuit is working, reliably passing data between the 
>> Arduino and a PC.
>> 
>> With the Thunderbolt is connected to the MAX232 no data passes.  Activity 
>> LEDs on the non-RS232 of the MAX232 circuit show no activity when the 
>> Thunderbolt is providing data, indicating the MAX232 is not performing the 
>> intended level translation.  I've scoped the RX/TX lines coming from the 
>> Thunderbolt both when connected to the Arduino and not.  There is a distinct 
>> difference. When disconnected, the pulses are about 10.3v and nice, crisp 
>> and square.  Connected, the pulses are ~50% lower in voltage (4.1v) showing 
>> an exponential rise in voltage and trace noise.
>> 
>> I'm pretty much stumped at the moment and wonder if anyone can offer a 
>> suggestion or thoughts on a direction to take.
>> 
>> Thanks in advance,
>> Dan Quigley (N7HQ)
>> 
>> 
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> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
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Re: [time-nuts] KS-24361 "NO GPS" - again

[bownes]

Typically the pins are two or three lengths. 

The longest pins are ground, the next are power, then signal pins. Quite often 
used for things that are hot swapped. Take a look at a USB cable for example. 





> On May 29, 2015, at 19:01, Chuck Harris  wrote:
> 
> Thees units were made for the phone company, and phone companies
> are big on "hot-swapping" modules.  The shorter pins are shortened
> to make sure that their circuit doesn't make contact until the
> longer pins have made contact.  Don't "fix" them!
> 
> -Chuck Harris
> 
> billriches wrote:
>> Hi Ulli,
>> 
>> I heard some comments that the short jumper cable between the two units
>> would make an intermittent connection.  You will notice that some of the
>> pins in the connector are shorter than the others and hopefully that is the
>> problem.  I don't know if the plugs are wired 1 to 1, 2 to 2 and so forth
>> but you could figure that out and make up another cable and try it.
>> Hopefully your problem will be as simple as a bad cable.  I have had two of
>> those systems running 24/7 for almost a year and have had no problems.
>> 
>> 73,
>> 
>> Bill, WA2DVU
>> Cape May
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Re: [time-nuts] Small time server for mobile use.

[bownes]

All interesting solutions. 

For the advocates of RPi solutions, I put about half a dozen in to support some 
non mission critical infrastructure about a year ago. We are using them for for 
logging, reading QR codes, running a vending machine, kiosk web browsers, and 
similar tasks. In short, nothing requiring heavily lifting. 

I've been incredibly dissappointed in the results. Well over half of them have 
needed replacement and not a one runs reliably. They need rebooting at 
intervals from hours to a few tens of days to recover from total lock up. The 
problem is not environmental, power or SD cards. 

As such, I'd be hard pressed to go with such a solution for Mark's problem. 

Soekris single board PCs are still out there, have a decent ecosystem, and are 
pretty rugged. Hard to beat for the budget requested. And decent GPS NTP 
implementations are documented. 

Failing that a nice used Symetricomm :)




> On May 12, 2015, at 21:09, Mark Spencer  wrote:
> 
> Thanks.   Yep running an extra Dc to Dc converter is an option but we already 
> have access to clean 28 and 13.8 VDC supplies with some extra capacity.  We 
> could likely provide up to a 100 watts of power for this system (I doubt it 
> would need that much.)
> 
> The hold over requirement is in the range of several hours.   The temperature 
> swings could be fairly large (ie. cold soak outside at minus 35C, then inside 
> a heated garage, plus what ever temperature the equipment bay rises to when 
> the vehicle has been operating for some time probably less than 85 deg C.) 
> mounting the equipment in locations other than the equipment bay would likely 
> result in lower max temperatures.
> 
> I'm not sure about the cooling capacity of the equipment bay, but there are 
> other areas with climate control systems where this device could be installed 
> if needed.  I'm fairly comfortable that a device that generated up to 100 
> watts of heat could be accommodated (ie, I would assume all of the electrical 
> power going into the device gets turned into heat) but would need to double 
> check this.
> 
> The size is somewhat flexible.
> 
> To a certain extent the requirements could be adjusted to fit an existing 
> COTS product that was perceived as generally suited to the application.   As 
> this is a one off requirement, that will be in use for a limited time some 
> limitations can be worked around or lived with.
> 
> The budget could be several thousand dollars.
> 
> I thought about a Raspberry Pi type of solution, but need to factor in the 
> cost of my time or that of someone else, plus there is a strong desire to 
> either drop in a COTS "black box" or use a laptop.
> 
> Thanks for the comments.
> 
> 
> Sent from my iPad
> 
>> On 2015-05-12, at 3:54 PM, Pete Stephenson  wrote:
>> 
>>> On Tue, May 12, 2015 at 7:11 PM, Mark Spencer  
>>> wrote:
>>> Hi sorry for a possibly OT post.
>>> Has anyone had practical experience with small commercially available time 
>>> servers / ntp servers suitable for mobile  use in a vehicle.
>> 
>> I don't know about any commercially-available products, but it sounds
>> like it'd be pretty straightforward to do with a Raspberry Pi or
>> something similar if you don't mind a little bit of DIY.
>> 
>> What constraints do you have on budget, size, power requirements, and 
>> cooling?
>> 
>>> The use case is I am in need of an accurate (ie.  within 100 ms) time 
>>> source for several pc's in moving vehicle.Being able to run directly 
>>> off a 13.8 or 28 VDC  source would be a major plus but AC power is also 
>>> available.
>> 
>> The Pi runs on 5V DC. DC-DC buck converters that can convert 7-35V to
>> 5V DC are cheap, efficient, and widely available. Shouldn't be a
>> problem.
>> 
>>> Hold over if there are gaps in GPS coverage is also a major plus.
>> 
>> How long would you need holdover? Seconds or minutes (e.g. driving
>> through a tunnel)? Hours? Days? Would the computers in the vehicle be
>> subject to large temperature shifts?
>> 
>> A Pi should be able to handle +/- 100ms of holdover in the
>> minutes-to-hours range using NTP.
>> 
>>> We already have a GPS with a 1 pps output, but an integrated box with it's 
>>> own GPS would be best.
>> 
>> A tiny integrated module like the Adafruit Ultimate GPS breakout[1] is
>> cheap, handy, and emits a 1PPS signal. It's also extremely small and
>> can be purchased in "hat" form[2] that mounts directly to the Pi.
>> 
>> Cheers!
>> -Pete
>> 
>> [1] https://www.adafruit.com/products/746
>> [2] https://www.adafruit.com/products/2324
>> 
>> -- 
>> Pete Stephenson
>> 
>>> On Tue, May 12, 2015 at 7:11 PM, Mark Spencer  
>>> wrote:
>>> Hi sorry for a possibly OT post.
>>> Has anyone had practical experience with small commercially available time 
>>> servers / ntp servers suitable for mobile  use in a vehicle.
>>> 
>>> The use case is I am in need of an accurate (ie.  within 100 ms) time 
>>> source for several pc's in moving vehicle.Being able to run directly 
>>> of

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  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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> > To unsubscribe, go to
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[time-nuts] HP Agilent 5061A Cesium Beam Frequency Standard

[bownes]

If anyone happens to be looking for a 5061A in the Bay Area this might be a 
good deal. 

Bob

View item:
HP Agilent 5061A Cesium Beam Frequency Standard

End Time: Feb 20, 2015, 18:32:56 EST




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Re: [time-nuts] Set time on Solaris computer from HP 58503A

[bownes]

> On Dec 14, 2014, at 07:42, Dr. David Kirkby (Kirkby Microwave Ltd) 
>  wrote:
> 
>> On 14 December 2014 at 11:57, Hal Murray  

> 
> That command works.
> 
> How do you reboot - apart from of course powering the thing off?
> 

# shutdown -y -i6 -g0

Or

# reboot

Or

# init 6

Bob
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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"  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  wrote:
>> 
>> On Thu, Dec 11, 2014 at 10:27 AM, Dan Drown 
>> 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] GPS in the news

[bownes]

I read the article and thought it would make for an interesting crowd sourced 
project if the sensitivity is large enough to build a distributed sensor 
network with GPSDOs. 



> On Nov 18, 2014, at 17:15, Magnus Danielson  
> wrote:
> 
> Hi Charles and Joe,
> 
> Read this, and hopefully you get smarter than from the write-up you linked:
> http://arxiv.org/pdf/1311.1244v2.pdf
> 
> I could not find any attempt at sensitivity scale required, and thus the 
> feasability of actually detecting these deviations.
> 
> From a quick look at it, I have a kind of notion of what they imply one 
> should look for, but it's not really well described exactly what to expect, 
> but maybe it becomes clearer on a quality read-through. It is more suggestive 
> than detailed method proposing, enough to show the idea, but not enough to 
> implement it, it needs the engineering on top of it.
> 
> Cheers,
> Magnus
> 
>> On 11/18/2014 03:12 PM, Joseph Gray wrote:
>> Yes, I read that yesterday. It will be interesting to hear what the
>> outcome of the study is.
>> 
>> Joe Gray
>> W5JG
>> 
>> 
>> On Tue, Nov 18, 2014 at 4:59 AM, Charles Steinmetz
>>  wrote:
>>> Dark matter the source of GPS irregularities?
>>> 
>>> 
>>> 
>>> Best regards,
>>> 
>>> Charles
>>> 
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Re: [time-nuts] 10811's

[bownes]

Is there a quick and dirty summary of which are the "good" 10811's? Otherwise, 
I clearly need to go through my collection and characterize them! :)

I should probably do that anyway...



> On Nov 17, 2014, at 21:50, Bob Camp  wrote:
> 
> Hi
> 
> As best anybody can tell, the improved phase noise and ADEV 10811’s came out 
> of a screening / select process. There is a finite chance that a “normal part 
> number” 10811 could be as good as or better than a part from one of the 
> “better part number” versions.
> 
> Bob
> 
>> On Nov 17, 2014, at 9:42 PM, John Allen  wrote:
>> 
>> As you all know, but has not been mentioned, is that there are many versions
>> of the venerable 10811, which different specifications, including phase
>> noise and stability.
>> 
>> 
>> 
>> The well known HP document 90027-1 lists many of them, and thanks to TVB, it
>> is here:
>> 
>> http://www.leapsecond.com/museum/10811a/90027-1.pdf
>> 
>> 
>> 
>> The contents include
>> 
>> 1 10811D/E Crystal Oscillators 2 10811D/E Option 001  3 10811D/E Option 002
>> 4 10811D/E Option 003  5 10811D/E Option 100 
>> 
>> 6 10811-60111 7 10811-60109 8 10811-60209 9 10811-60211 10 10811-60102 11
>> 05071-60219 12 10811-60158 13 10811-60160 
>> 
>> 14 10811-60164
>> 
>> 
>> 
>> I hope that this is helpful. Regards, John K1AE
>> 
>> 
>> 
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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  
> 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  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  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]

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  wrote:

> On Mon, 3 Nov 2014 11:54:41 -0800
> Peter Monta  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]

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  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]

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  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" 
> 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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Re: [time-nuts] 5370 processor boards available

[bownes]

At that point, why not just remove the few remaining HP parts and put them in a 
new enclosure? :)



> On Oct 8, 2014, at 10:29, Pete Lancashire  wrote:
> 
> One future project would be to replace the front panel with a LCD/Touch
> Panel
> 
> 
> 
>> On Wed, Oct 8, 2014 at 6:56 AM, Chuck Harris  wrote:
>> 
>> Hi Magnus,
>> 
>> As one of the charter users of the board, I know that.  I was hoping
>> that some of the other users might elaborate on what John's board has
>> done for them that they wouldn't have done otherwise.
>> 
>> The addition of a BBB inside of a 5370 just reeks of future capabilities,
>> and possibilities.  How have these opportunities been exploited?
>> 
>> I quite enjoy being able to run my 5370 in the lab when I am in my
>> office... but that is a luxury, not a need... for me.
>> 
>> -Chuck Harris
>> 
>> Magnus Danielson wrote:
>> 
>>> Hi Chuck,
>>> 
>>> The benefit is that you can use Ethernet straight into the 5370, you can
>>> get much
>>> higher sampling rates and well, we can have fun hacking up more
>>> functionalities into
>>> the 5370 native support if we like to.
>>> 
>>> Cheers,
>>> Magnus
>>> 
 On 10/08/2014 02:46 PM, Chuck Harris wrote:
 
 Hi John,
 
 Can you share with the group any interesting applications this
 new processor board has enabled?
 
 Other than turning the 5370A into a capable replacement for the
 5370B...
 
 -Chuck Harris
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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] Oscilloquartz 3210 Cesium Standard

[bownes]

Careful Chris, it sounds like you are developing the symptoms of the Vintage 
strain of the time nuts infection. Next thing you know, you will be looking at 
tall clocks. 

Bob, who is debating the wisdom of non invasively synchronizing the family 
heirloom tall clock to the new cesium clock...

> On Aug 28, 2014, at 10:33, 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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[time-nuts] MIT Flea

[bownes]

Apologies for to those not in New England or not going to the Flea. 

I'm heading out to the MIT Flea at oh-freaking-dark in the morning and I know 
there are often several time nuts who go. If you happen to see a guy wander by 
in a Horton Emergency Vehicles hat looking very tired, say Hi!
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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  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 
> 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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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  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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[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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Re: [time-nuts] Time Code Units Available

[bownes]

Walter,

If the two datachron units and the datum 9300 are still available, I would be 
most interested. 

Thanks!
Bob

> On Jul 8, 2014, at 17:08, walter shawlee 2  wrote:
> 
> (very sorry for the first file size! Here's a smaller one)
> 
> Since there were several requests for more details, here's the various*time 
> code units *we have, numbers following in () are *quantities*. Sorry, the 
> fluke 207-1 VLF receiver is gone.
> 
> A pic is attached to show some units and the condition (very good), and 
> here's a list of what I found in one building.
> 
> There are probably more elsewhere, but I have to search further later. I 
> remain mystified as to *why* I thought we needed all these at some earlier 
> time.  We also have a huge quantity of stabilized/TCXO oscillator modules if 
> interested. probably more fun to snorkel through them in person, however.
> 
> *TRAK:*
> 
> 8400 Time Code Translator/Generator
> 
> 8390 Time Code Generator (2)
> 
> 8392 Countdown Reader
> 
> 8397-4 Time Code Translator (3)
> 
> 8397-8 Time Code Translator (2)
> 
> *OTHERS:*
> 
> Kinemetrics/Truetime 60DC NBS Time (WWVB)
> 
> Kinemetrics/Truetime 468DC NBS Time (Satellite)
> 
> (*I believe these are complete receivers, but both need antennas I do not 
> have*)
> 
> KODE Inc. TCU
> 
> DATACHRON 3700 CDU (Large display) ($40)
> 
> DATACHRON 3070 Time Code Translator/Generator
> 
> Anadex Counter CF-601R (seems to be second counters w/plasma displays) (2)
> 
> Datum 9300 Time Code Generator/Translator ($25)
> 
> ODETICS 285 Time Code Unit
> 
> Time Code Generators are $50 each, Translators/Displays are $30 each.
> the Kinemetrics and Odetics units are $50 each.
> all are as-is, as shown in the pic. shipping is extra.
> If you are coming up for the August 1/2 Free Stuff session,
> we will toss some of these into the free pile!
> 
> all the best,
> walter
> 
> -- 
> Walter Shawlee 2, President
> Sphere Research Corporation
> 3394 Sunnyside Rd.,  West Kelowna,  BC
> V1Z 2V4  CANADA  Phone: (250) 769-1834
> walt...@sphere.bc.ca
> WS2: We're all in one boat, no matter how it looks to you
> 
> 
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Re: [time-nuts] GPSDO standard interface?

[bownes]

Well, I built one of the ve2zaz units, and it has a. Pretty well defined serial 
interface. On the other hand, the one I use most has a PIC and an LCD, no 
serial interface. 

> On Jun 25, 2014, at 20:10, Bob Stewart  wrote:
> 
> In an offline communication, I suddenly realized that I hadn't given any 
> thought to the user interface for my GPSDO.  Is there an accepted standard 
> interface for GPSDOs, or is that a murky Microsoft-esque world of patents and 
> lawyers?
> 
> 
> Bob - AE6RV
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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 wrote:

> 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" 
> 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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