Re: [time-nuts] [EXTERNAL EMAIL] Sayrosa 607B Frequency Synthesiser

[REEVES Paul]

Hi Nigel,

It will also be the first info on the 607B that I have ever seen I will 
certainly download it when I get home (work filtering forbids it, with much 
else). Should allow me to fish my one out of the attic and actually use it 
- after letting the magic smoke out of the tants, of course :-)
Many thanks, in advance, for your efforts.

Regards,
Paul,G8GJA

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of gandalfg8--- 
via time-nuts
Sent: 10 June 2018 20:31
To: time-nuts@febo.com
Subject: [EXTERNAL EMAIL] [time-nuts] Sayrosa 607B Frequency Synthesiser

Perhaps not a very common item, and probably restricted to the UK, but I have 
seen these mentioned here before.

The 607B was a very nice 2 to 30MHz synthesiser used as the drive unit in the 
UK Diplomatic Service Piccolo radio system.

Both Sayrosa and Piccolo are long gone, and information has always been hard to 
come by, but I've just scanned the 607B Training Manual and 607B Technical 
Handbook and uploaded PDF versions of both to Mediafire.

This documentation is quite limited but so far is all I've ever seen for the 
607B.

Both can be found in a single file at

http://www.mediafire.com/file/c6vv5t71cq741sd/Sayrosa%20607B.zip

For what it's worth, my experience with these has been that by far the most 
common fault is the familiar shorted tantalum syndrome.

Nigel GM8PZR
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Re: [time-nuts] 4046 replacement

[REEVES Paul]

Hi Donald,

I've just had this problem - the 'signal' input (p14) to the phase detectors is 
a 'bodge' linear amplifier built around standard CMOS stages and it doesn’t 
work right. A resistor around a CMOS inverter was a good old recipe to get a 
'linear' amplifier stage but this design appears to have a voltage variable 
resistor of sorts and it gives very strange results. It is fine if used as a 
CMOS level i/p stage but its use as an  ac coupled low level i/p is problematic 
and may need additional loading. Manufacturer's documentation is scarce and I 
have only seen one reference to the internal design of this stage. There's 
quite a bit about it in several places on the net.

Regards,
Paul   Reeves  G8GJA

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of donald collie
Sent: 18 April 2018 10:40
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 4046 replacement

Thankyou Attila. I remember reading a book on PLL theory, recently,writen by a 
very knowledgable fellow, but I didn`t think to make a copy of his critique of 
the 4046. I recall that the nub of it was that the 4046 isn`t suitable for some 
applications because of a design flaw. Perhaps somebody in this group could 
explain further.
Thankyou Bill, for the datasheet on the 74HCT9046, and your comments 
Cheers!..Don
jnr ZL4GX


Virus-free.
www.avg.com

<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

On Wed, Apr 18, 2018 at 8:28 PM, wb6bnq  wrote:

> Hi Donald,
>
> You could consider the NXP 74HCT9046A as a replacement.  It is an 
> improved version of 4046.  However, you do need to study the spec 
> sheet as it is a bit different, but in a good way.
>
> I have included an attached PDF of the spec sheet, if it makes through 
> the mail list server.
>
> BillWB6BNQ
>
>
> donald collie wrote:
>
> I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but 
> have
>> recently read that this CMOS IC has a design flaw. What would be a 
>> better chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s 
>> if it doesn`t have the same bug], or a 74HC7046AN - which is similar. 
>> Both these chips are more-or-less pin compatable TIA for any 
>> advice!.
>> ..Don
>>
>> > source=link_campaign=sig-email_content=webmail>
>> Virus-free.
>> www.avg.com
>> > source=link_campaign=sig-email_content=webmail>
>> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>> ___
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>>
>
>
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[time-nuts] E-Loran

[REEVES Paul]

Looks like the S. Koreans are pressing ahead with their e-Loran system.
http://insidegnss.com/node/5598

'Old' tech never dies

Paul G8GJA
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Re: [time-nuts] Ships fooled in GPS spoofing attack suggest Russian cyberweapon

[REEVES Paul]

This was referred to in my post (subject: 'Loran') on 8/8/17 and was a news 
item in 'Inside GNSS' and other journals before that. Didn't get many comments 
on my post :-(  
 Must have used the wrong subject

Paul  G8GJA

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John Allen
Sent: 12 August 2017 22:23
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Ships fooled in GPS spoofing attack suggest Russian 
cyberweapon

FYI, John K1AE

-Original Message-
From: YCCC [mailto:yccc-boun...@contesting.com] On Behalf Of ROBERT DOHERTY
Sent: Saturday, August 12, 2017 9:26 AM
To: YCCC Reflector
Subject: [YCCC] Fwd: Re: [Radio Officers, ] Ships fooled in GPS spoofing 
attack suggest Russian cyberweapon

As if there were not enough problems in the world .

Whitey  K1VV  

> Date: August 12, 2017 at 7:37 AM
> Subject: Re: [Radio Officers, ] Ships fooled in GPS spoofing 
> attack suggest Russian cyberweapon
> 
> Ships fooled in GPS spoofing attack suggest Russian cyberweapon
> 
> News from: New Scientis (article reported by R/O Luca Milone – 
> IZ7GEG)
> 
> 
> https://www.newscientist.com/article/2143499-ships-fooled-in-gps-spoof
> ing-attack-suggest-russian-cyberweapon/#.WY6zNfZq1VA.google_plusone_sh
> are 
> https://www.newscientist.com/article/2143499-ships-fooled-in-gps-spoof
> ing-attack-suggest-russian-cyberweapon/#.WY6zNfZq1VA.google_plusone_sh
> are
> 
> 
> On date: 10 August 2017
> 
> By David Hambling
> 
> 
> Reports of satellite navigation problems in the Black Sea suggest that 
> Russia may be testing a new system for spoofing GPS, New Scientist has 
> learned. This could be the first hint of a new form of electronic warfare 
> available to everyone from rogue nation states to petty criminals.
> 
> 
> On 22 June, the US Maritime Administration filed a seemingly bland 
> incident report. The master of a ship off the Russian port of Novorossiysk 
> had discovered his GPS put him in the wrong spot – more than 32 kilometres 
> inland, at Gelendzhik Airport.
> 
> 
> After checking the navigation equipment was working properly, the captain 
> contacted other nearby ships. Their AIS traces – signals from the automatic 
> identification system used to track vessels – placed them all at the same 
> airport. At least 20 ships were affected 
> http://maritime-executive.com/editorials/mass-gps-spoofing-attack-in-black-sea
>  .
> 
>  
> While the incident is not yet confirmed, experts think this is the first 
> documented use of GPS misdirection – 
> https://www.marad.dot.gov/msci/alert/2017/2017-005a-gps-interference-black-sea/
>   a spoofing attack that has long been warned of but never been seen in the 
> wild.
> 
> 
> Until now, the biggest worry for GPS has been it can be jammed 
> https://www.newscientist.com/article/dn20202-gps-chaos-how-a-30-box-can-jam-your-life/
>   by masking the GPS satellite signal with noise. While this can cause chaos, 
> it is also easy to detect. GPS receivers sound an alarm when they lose the 
> signal due to jamming. Spoofing is more insidious: a false signal from a 
> ground station simply confuses a satellite receiver. “Jamming just causes the 
> receiver to die, spoofing causes the receiver to lie,” says consultant David 
> Last http://www.professordavidlast.co.uk/ , former president of the UK’s 
> Royal Institute of Navigation.
> 
> 
> Todd Humphreys 
> http://www.ae.utexas.edu/faculty/faculty-directory/humphreys , of the 
> University of Texas at Austin, has been warning of the coming danger of GPS 
> spoofing for many years. In 2013, he showed how a superyacht with 
> state-of-the-art navigation could be lured off-course by GPS spoofing. “The 
> receiver’s behaviour in the Black Sea incident was much like during the 
> controlled attacks http://onlinelibrary.wiley.com/doi/10.1002/navi.183/full  
> my team conducted,” says Humphreys.
> 
> 
> Humphreys thinks this is Russia experimenting with a new form of 
> electronic warfare. Over the past year, GPS spoofing has been causing chaos 
> for the receivers on phone apps in central Moscow to misbehave 
> https://themoscowtimes.com/articles/the-kremlin-eats-gps-for-breakfast-55823 
> . The scale of the problem did not become apparent until people began trying 
> to play Pokemon Go. The fake signal, which seems to centre on the Kremlin, 
> relocates anyone nearby to Vnukovo Airport 
> http://www.thetruthaboutcars.com/2017/01/bizarre-gps-spoofing-means-drivers-near-kremlin-always-airport/
>  , 32 km away. This is probably for defensive reasons; many NATO guided 
> bombs, missiles and drones rely on GPS navigation, and successful spoofing 
> would make it impossible for them to hit their targets.
> 
> 
> But now the geolocation interference is being used far away from the 
> Kremlin. Some worry that this means that spoofing is getting easier. GPS 
> spoofing previously required 

[time-nuts] Loran

[REEVES Paul]

And a link to a recent article about the possibility of Loran coming back   
 or, at least, you are thinking about it over there.

https://arstechnica.co.uk/gadgets/2017/08/radio-navigation-set-to-make-global-return-as-gps-backup-because-cyber/

Paul Reeves, G8GJA
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Re: [time-nuts] Vintage Frequency Measurement

[REEVES Paul]

The start of the next sentence has been incorporated in the link. Just remove 
the "So" at the endworks fine.

Regards, 
PaulG8GJA

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp
Sent: 15 February 2017 12:36
To: Robert Atkinson; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Vintage Frequency Measurement

Hi

The link gives an error, but I have no doubt that the meaning of the term 
varies a bit. 
Thanks for the reference. I’ll try to get it working from here. 

Bob

> On Feb 15, 2017, at 2:28 AM, Robert Atkinson via time-nuts 
>  wrote:
> 
> Hi,Sorry if I caused confusion by calling the SCR/BC221 a wavemeter. Clearly 
> it's not in the wider usage of the term, and the manual and front panel call 
> it a frequency meter. However the similar British device was called a 
> wavemeter "Wavemeter Class D" 
> http://www.vmarsmanuals.co.uk/archive/724_Wavemeter_Class_D_No2_Working_Instructions.pdfSo
>  here in the UK the 221 was often also called a wavemeter. Classic wavemeters 
> were also available for example the Marconi TF975.
> Robert G8RPI.
> 
>  From: Bob Camp 
> To: Discussion of precise time and frequency measurement 
> 
> Sent: Monday, 13 February 2017, 23:46
> Subject: Re: [time-nuts] Vintage Frequency Measurement
> 
> Hi
> 
> With a VFO running, you have a heterodyne frequency meter. That is (at 
> least to me) a very different device than an absorption wave meter. I 
> know way to put power into a BC-221 and use it as an absorption device.
> 
> I’m not in any way saying that the LM or the 221 are less useful. They 
> are still to this day great little boxes. The just aren’t (by my 
> understanding) wave meters. That term describes a different device that works 
> a different way.
> 
> Bob
> 
>> On Feb 13, 2017, at 5:52 PM, John Miles  wrote:
>> 
> 
> 
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Re: [time-nuts] Thermal effects on cables

[REEVES Paul]

Hi Attila,

I quite agree, I should have remembered that but I tend to use fairly small 
coax anyway at those frequencies as a matter of course and it didn't register 
as something that needed saying. My fault!
It can be quite difficult to get people to notice the difference between SMA 
and 3.5mm - I have often had to repeatedly remind some of our test technicians 
of the difference as they tend to think they are interchangeable with the 
unfortunate results you describe :-(It is just as well that the 3.5mm cal 
kit for the HP8510 (still a fine VNA, if lacking a few of the new bells and 
whistles) is a work of art with DTIs for checking the mechanical setup of the 
connectors - they are not just for show!

Regards,

Paul Reeves

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila Kinali
Sent: 23 January 2017 19:33
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thermal effects on cables

On Mon, 23 Jan 2017 15:13:39 +
REEVES Paul <paul.ree...@uk.thalesgroup.com> wrote:

> Surely the impedance of the cable is only affected by the ratio of the 
> inner conductor and outer conductor diameters modified by the internal 
> dielectric constant, nothing to do with the frequency of operation. 
> You might well have problems converting the larger diameters down to a 
> suitable size for the connectors at the higher frequencies though

If you are only looking at the impedance, then yes. But once you get to high 
frequencies, you get also multi-mode behaviour of the coax cables and 
connectors, which leads to dispersion. That's why people hardly use N 
connectors for GHz frequencies, even though the connector itself would allow 
it. For VNAs where even small phase shifts/instabilities due to multi-mode 
behaviour/dispersion are a no go, the connectors are usually 3.5mm (basically a 
precise version of the SMA), 2.9mm, 2,4mm etc and go down to even 1.0mm which 
can be spec'ed up to 110GHz.

BTW: the 3.5mm connector is one that you will find on many instruments that go 
beyond 1-2GHz. Unfortunately it looks exactly the same as an SMA connector and 
will mate with one. Even more unfortunately, mating it with an SMA connector 
will scar the connector and most likely move it out of spec (ie degrade it to a 
simple SMA connector). If it's just an adapter, you've only lost a bit of money 
(in the order of a few €100).
If it was the connector of your VNA/oscilloscope/..., you might need to send it 
in for an expensive repair.

Attila Kinali

--
You know, the very powerful and the very stupid have one thing in common.
They don't alters their views to fit the facts, they alter the facts to fit the 
views, which can be uncomfortable if you happen to be one of the facts that 
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Re: [time-nuts] Thermal effects on cables

[REEVES Paul]

Hi David,

Surely the impedance of the cable is only affected by the ratio of the inner 
conductor and outer conductor diameters modified by the internal dielectric 
constant, nothing to do with the frequency of operation. You might well have 
problems converting the larger diameters down to a suitable size for the 
connectors at the higher frequencies though
I thought that the HP cabling for the 8510 series VNAs was air spaced but I 
might well be wrong - I just tried not to damage them :-)
Regards,

Paul Reeves

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David 
Kirkby (Kirkby Microwave Ltd)
Sent: 23 January 2017 13:26
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thermal effects on cables

On 13 January 2017 at 06:52, Ole Petter Ronningen 
wrote:

> Hi, all
>
> The question of phase shifts in cables pops up every now and then on 
> this list - I stumbled across a good table of measured phase shifts 
> with temperature in different cable types in this paper:
> http://www.ira.inaf.it/eratec/gothenburg/presentations/ERATEC_2014_
> PresentationWSchaefer.pdf
> that I though would be of interest to others.
>
>
I've like to know how VNA cables compare. They are expensive enough - a couple 
of cables around 600 mm long (24") for my VNA are over $5000. They are much 
larger diameter than normal cables, but much more flexible too.
The construction is obviously very different. Since mine are designed for use 
to 26.5 GHz, the internal diameter of the outer conductor can be no more than a 
couple of mm, yet the overall cable has a diameter of about 15 mm.

Dave
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[time-nuts] Galileo clock failure

[REEVES Paul]

It seems like the Rb and H-maser clocks on the Galileo satellites might be 
experiencing a problem
Here is a link to a BBC report:
http://www.bbc.co.uk/news/science-environment-38664225

"What do you mean, ' nobody told us they were meant to work in vacuum'  ?"
Paul Reeves
Senior Engineer

Thales UK
Ocean House, Throop Road, Templecombe, Somerset,  BA8 0DH, UK
www.thalesgroup.com/uk

Tel: +44 (0)1963 372851.  Mob: +44 (0) 00.  Fax: +44 (0)  00.
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Re: [time-nuts] low noise multiplication to 100 MHz

[REEVES Paul]

Why not use something like an HP5254B/C ? They give out  50MHz harmonics up to 
the low Ghz region, all filtered by a nice high-Q tuneable cavity. All to 
typical HP build quality.
Of course, they have an amount of 'not needed' circuitry and are just a bit  
. , well, bulky.  Good clean output from 10MHz in though.

Paul   G8GJA

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Reilley
Sent: 21 January 2016 15:17
To: time-nuts@febo.com
Subject: Re: [time-nuts] low noise multiplication to 100 MHz

Have you considered synthesizers?   I am using an Analog Devices AD9517 
to drive a A/D
converter at 250 MHz.   It has many clock outputs that are independently 
configurable.
It is intended for low jitter applications.

Pete.

On 1/21/2016 9:43 AM, jimlux wrote:
> My tiny 100 MHz low noise OCXOs are unexpectedly delayed at the mfr, 
> and I'm looking at alternative schemes.
> One is to get 10 or 20 MHz OCXOs (typically in stock) and multiply 
> them up. I've got the Wenzel ap notes on 2diode and using HCMOS (and 
> I've used the packaged Wenzel multipliers), and I think I have some 
> spare board real estate on another board.
>
> The 2diode multiplier describes using 1n5711 or 1n914, but I was 
> wondering if anyone has run this sort of multiplier up to 100 MHz?
>
> What sort of symmetry does the resulting waveform have (yeah, it's 
> basically a filtered sinewave, because you're picking a harmonic, but 
> I've been surprised before)?
>
>
>
>
> I'm driving an FPGA and a couple of ADCs.  The ADCs have differential 
> input that is 10kohms with 9pF in parallel offset from ground in the 
> usual way (we're using a transformer and appropriate bias resistors).
> Not a 50 ohm load, in any case.  And it wants a clock that is high for 
> about 47.5% to 52.5% in one mode and much wider (30%-70% in another)..
> I need to check.
>
> The FPGA is less critical noise-wise, and has a AD8138 buffer in any 
> case, which can fix a variety of evils.
>
>
>
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Re: [time-nuts] End of Loran-C in Europe confirmed.

[REEVES Paul]

Hi Iain,



...and a damned shame too - there goes another standard. Just when the 
Americans seem to be doing a u-turn :-)

Regards,

Paul

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Iain Young
Sent: 17 December 2015 12:22
To: time-nuts@febo.com
Subject: Re: [time-nuts] End of Loran-C in Europe confirmed.

On 17/12/15 10:50, Poul-Henning Kamp wrote:

> I've spent some time tracking this down, but it looks like all Loran-C 
> in Europe shuts down on new-years eve.
>
> The only station I have not found official confirmation for is Sylt, 
> but France, Norway, Denmark and UK have all officially announced 
> shut-down of their stations.

Do you have the UK announcement ? I got notification of Lessay, Soustons, and 
the control station at Brest, but not for Sylt or Anthorn.

The UK is (supposedly) supportive of eLORAN, and I thought Anthorn (along with 
some extra stations on the south coast) were indeed transmitting eLORAN.

With eLORAN being backwardly compatible, I was assuming/hoping at lease Anthorn 
would keep my Austron's busy :)


Iain
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Re: [time-nuts] What sort of oscillator is this?

[REEVES Paul]

David,

Just a thought but have you tried Pasternack? They do 'custom' precision 
cabling including 2.4mm connector options.

regards,

Paul,   G8GJA

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David 
Kirkby (Kirkby Microwave Ltd)
Sent: 30 September 2014 00:16
To: Discussion of precise time and frequency measurement
Cc: hmur...@megapathdsl.net
Subject: Re: [time-nuts] What sort of oscillator is this?

On 29 Sep 2014 20:06, Hal Murray hmur...@megapathdsl.net wrote:


drkir...@kirkbymicrowave.co.uksaid:
  Unfortunately Keysight have now sold all the cables, but do have the
front
  panel overlay which is arguably the most critical item.

  Spending £500 on 5 cables and a front panel overly is more attractive
than
  spending £8000 on an upgrading the model.

 For £500, I'll bet you can get a good hand crimp tool, some good coax,
and a
 handful of connectors.

Yes, but I have no way to test them. I don't have a 2.4 mm connector gage,
and I am not keen to put 2.4 mm plugs into something very expensive without
checking the pin depth first.

I don't have a 2.4 mm cal kit, so I can't check the return loss.

I would really like to find a male 2.4 mm connector gage and satisfy myself
the cables, even if I get them professionally made.

I believe someone might have some 2.4 mm HP cables. I can put the SMA on
and at least check the pin depth.

Dave.
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Re: [time-nuts] GPSDO standard interface?

[REEVES Paul]

Chris,
NMEA is a good 'general purpose' interface for GPS units but I thought this 
thread was about the GPSDO interface. Not quite the same - TSIP/SCPI would make 
rather more sense here, especially with all those Thunderbolts about :-)
Most GPS receivers still supply at least one serial interface even if a USB 
interface is included too. Consumer grade 'very small' navigation type GPS 
units may dispense with the serial ports but we are not too worried about those 
devices, surely? I don't see why a serial to USB converter would be needed - 
serial ports are still available on a reasonably large number of motherboards, 
especially if you are using mini-ITX or similar for embedded projects, and a 
hardware UART is a much more reliable interface. USB/serial adaptors 'still' 
give erratic results and scanning usb ports for new devices is also a bit of a 
lottery at times.
A serial interface is also the easiest to convert to a more 'robust' physical 
media for electrically 'unpleasant' environments  and DB9/25 connectors are 
a LOT more reliable than USB connectors too!

regards,

PaulG8GJA
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Chris Albertson
Sent: 26 June 2014 08:13
To: Bob Stewart; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPSDO standard interface?

If you want a common interface for GPS receivers it's NMEA and it's
relatively easy to implement.  I certain would NOT translate to TSIP as
that is rather obscure.  NMEA is a very common standard and many GPSes can
output NMEA.

Also you talked about serial.  I hate to say it but who in 2014 wants a
serial device?  USB is the only reasonable interface to a computer.  If you
used serial then you would just need to buy a serial to USB adapter so you
may as well build that into  your controller.   In 2014 those old DB9 and
DB25 connectors should be banned from all new designs.

Realistically the user interface in most home made gear is a few #ifdef
in the code at the top of the file.  You change those and recompile and
send the new software to the controller.  It's not bad having to re-compile
in order to support a different GPS receiver.  You would not want to swap
the brand of GPS in a user interface.  You do that with solder and wires
and recompiling


On Wed, Jun 25, 2014 at 8:14 PM, Bob Stewart b...@evoria.net wrote:

 After reading Chris's response, it dawned on me that I'm treading a
 different path from what I've seen on the list.  It's not so much a GPSDO
 as a general purpose GPSDO engine.  It uses a number of ideas from Bert's
 board, like the dual-rail op-amp output, but it also has a TIC, so it will
 have sawtooth correction.  I have included 2 TTY ports: one for the
 receiver and one for the PC interface.  I'm going to use the DAC on the
 dsPIC, but there will be an SPI port that can be used to drive an off-board
 DAC, instead.  There's also the possibility of switching some stuff around
 and having an I2C port, and the ICSP header could also hook up to an
 additional thermistor or two, or perform other digital functions.


 So, there will be some minor user fiddling, like with Bert's board, due to
 the flexibility of the OCXO.  But, I'll be using the P and D from the PID
 control system, so it shouldn't be difficult to setup.  There will be a
 power LED, an output enable LED, and a bi-color LED to signify status, but
 only the status would be necessary.  I'll do what I can to make it smart
 enough to plug and play for most circumstances, but I only have the one
 OCXO brand to test with at the moment.  I do have 3 receivers to test with
 now: Adafruit, UT+, and LEA-6T.  Keep in mind that I don't expect this to
 be a lucrative commercial business venture, so my budget is almost
 nonexistent.


 I'll look into both SCPI and TSIP, and therein lies the reason for my
 original post.  Essentially, have they been patented, and if so, have those
 patents expired?  Some companies guard their interfaces very rigorously to
 forestall competitive disruption.  I don't want to suddenly get a cease and
 desist letter or a notice of lawsuit over a hobbyist kit.  It's one thing
 to provide open source software to monitor/control a successful product.
 It's an entirely different thing to provide an alternative product with an
 identical user interface.

 I just ordered the first prototype boards today, but the software should
 be just a rewrite of what I did for the TIC on Bert's board, with a lot of
 extras thrown in.  Not that that doesn't mean a lot of work, of course.


 Bob



 
  From: Tom Van Baak t...@leapsecond.com
 To: Discussion of precise time and frequency measurement 
 time-nuts@febo.com
 Sent: Wednesday, June 25, 2014 9:02 PM
 Subject: Re: [time-nuts] GPSDO standard interface?


 Bob,

 A couple of different ideas:

 1) No UI at all. The surplus GPSDO favorites over the years (like the HP
 SmartClock's and 

Re: [time-nuts] FE5680 GPS Disciplined Controller

[REEVES Paul]

Hi Bert,

I would definitely be interested in a kit.

regards,
Paul G8GJA

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of ewkeh...@aol.com
Sent: 18 June 2014 19:49
To: time-nuts@febo.com
Subject: [time-nuts] FE5680 GPS Disciplined Controller


FE5680 GPS Disciplined  Controller
With all the FE  5680 rubidium oscillators being used as door stops out there 
some of us decided  to develop a GPSDO for it. The main question we have:
Is there sufficient  interest among time nuts for a discipline controller for 
the FE5680 to make it  available? Looking at the postings over the last two 
years I am not so  sure.
The  construction and preliminary testing of a Brooks Shera style GPS 
discipline  controller for the later version (6.81e-13 resolution) of the 
FE5680 has been  completed. We are trying to determine the number of people 
that would be  interested in obtaining an FE5680 discipline controller (if 
there is sufficient  interest about $45 a kit shipping included, $75 for an 
assembled and tested  board, international orders for an additional $5) when it 
is released.
We are also looking for three Beta  testers that would be willing to purchase, 
assemble, and test our Beta release  controller kit with their own FE5680A and 
GPS receiver or Tbolt and provide  feedback. Please send an email to
_EWKehren@aol.com_ (mailto:ewkeh...@aol.com)   Subject Time-Nuts FE 5680A,
if you would be interested in being one of the three  Beta testers. A key 
requirement is the willingness to get to it right away, the  board assembly 
takes about 30 minutes. Instrumentation to measure results is  also a 
requirement. We obtained impressive results using a cheap ublox 6M  receiver.

The  FE5680 GPS discipline controller is a small (2” x 2”) board using 8 DIP’s 
and 1  SOT23-5 package powered by +5v with 0.1” headers for all inputs and 
outputs. Our  plan is to have the kit supplier solder in the only SMD device on 
the board. A  GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board 
with two 9600  baud serial ports sending TTL level tuning commands to the 
FE5680 and receiving  commands from and sending status data to a PC for data 
logging and system  control via a simple terminal program.
In the chip count are  two opto couplers that allow the use of isolated TTL to 
USB conversion. These  USB adapters are readily available and furnish the 5 V 
necessary for the  secondary of the opto circuit. An option is to not use the 
opto couplers and  send the PIC TTL level RX and TX into a TTL to
RS232 adapter. Another option is  to use a TTL to RS232 converter after the 
opto couplers but then an external 5 V  source would have to be supplied for 
the opto couplers.
As I  mentioned before to get best performance from the FE5680 temperature 
control is  a must and after much fan and metal work I realized that a Lap Top 
heat pipe is  the easiest lowest cost solution. Comments appreciated. As an 
alternative the  temperature correction needs to be disabled.  Otherwise two 
control loops fight each  other.  If you look close on page 7  of the brochure 
temperature stability from –10 to +60 C looks good but a closer  look and you 
see 4 E-11 changes over small temperature changes in the -10 to 60 C range. 
Extensive analysis has been done on the FE 5680 A and maybe some one  can 
tackle that problem. Please look at what N5TNL did. It is attached and click  
on his link. The FE 5680A does have a 4 channel MAX 1246 ADC and most likely it 
 is used to monitor temperature.
Also  mentioned before the FE 5680 output is not the cleanest, I did observe it 
and  some one posted the attached. I apologize but my records do not show who 
did, so  if you posted the data please come forward. For serious applications 
where you  are using it as your main reference a clean up like the Morion MV89 
or HP 10811  should be considered.
This  addition is not required for beta tests but temperature control will help.
I am also  enclosing the express PCB layout, be free to use it but it would be 
more  economical to do a group buy if there is enough interest and some one 
steps up  to kit.
Bert  Kehren
To  not exceed the attachment limit the plot will be a separate  posting





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Re: [time-nuts] optically excite a quartz crystal?

[REEVES Paul]

I'll have to check (dig it out from under a pile of gear.) but if I 
remember correctly the HRO receiver (at least the early, pre-war, ones) had a 
'non-contact' crystal holder for the IF notch filter. The crystal was a block 
about 1/2 square and a bit less thick (-ish) and fitted loosely between two 
support plates which incorporated the electrodes. It was certainly not a tight 
fit and the crystal could be easily removed.

Paul ReevesG8GJA

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Chuck Harris
Sent: 21 April 2014 14:01
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] optically excite a quartz crystal?

I'm puzzling over this statement.  The FT-243's I have seen have a spring
that squishes the quartz blank between the electrodes.  They aren't plated
onto the quartz, but they are still in intimate mechanical and electrical
contact.

-Chuck Harris

Bob Camp wrote:
 Hi

 The WWII era FT-243 is one example of a crystal that has the active portion 
 of the
 electrodes separated from the resonator by an air gap. There are lots of 
 similar
 holders from that era that do pretty much the same thing. Non-contacting
 electrodes are not very new.

 Bob
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[time-nuts] zero crossing detector in PIC mcu

[REEVES Paul]

This might have been mentioned before in the discussions on zero crossing 
detection for mains power monitoring (apologies if I missed it) but this chip 
(or series thereof) looks interesting -

http://www.eejournal.com/archives/articles/20140409-tinyterror/

and the article is fairly amusing too - who hasn't been confused by Microchip's 
numbering system?

Paul Reeves
Senior Engineer

Thales UK
Ocean House, Throop Road, Templecombe, Somerset,  BA8 0DH, UK
www.thalesgroup.com/uk

Tel: +44 (0)1963 372851.  Mob: +44 (0) 00.  Fax: +44 (0)  00.
e-mail: paul.ree...@uk.thalesgroup.com

Please consider the environment before printing a hard copy of this e-mail.

The information contained in this e-mail is confidential. It is intended only 
for the stated addressee(s) and access to it by any other person is 
unauthorised. If you are not an addressee, you must not disclose, copy, 
circulate or in any other way use or rely on the information contained in this 
e-mail. Such unauthorised use may be unlawful. If you have received this e-mail 
in error, please inform us immediately on +44 (0) 00 and delete it and 
all copies from your system.

Thales Corporate Services Limited. A company registered in England and Wales. 
Registered Office: 2 Dashwood Lang Road, The Bourne Business Park, Addlestone, 
Weybridge, Surrey KT15 2NX. Registered Number: 959962.

Thales UK Limited. A company registered in England and Wales. Registered 
Office: 2 Dashwood Lang Road, The Bourne Business Park, Addlestone, Weybridge, 
Surrey KT15 2NX. Registered Number: 868273

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Re: [time-nuts] Choke Ring Antenna - Patch Placement?

[REEVES Paul]

Hi Bob,

Not quite true, the first couple of sentences are ok but the helix antennas 
used for GPS are quadrifilar volute helices, not the longer axial mode type, 
and their gain characteristic can be modified to provide an almost perfect 
pattern for satellite reception with a 'flat-top' elevation response and higher 
gain over the 30-60(-ish) degree area.

regards,

PaulG8GJA


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Bob Camp
Sent: 11 October 2013 01:03
To: Bob Stewart; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Choke Ring Antenna - Patch Placement?

..
An ideal GPS antenna would not have a lot of gain straight overhead. You have 
less atmospheric loss in that direction. What you would want is an antenna 
that has some gain at 30 to 60 degrees. That was the issue with the helix 
antennas. They have gain straight up (and thus less at other angles).

Bob

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Re: [time-nuts] Pulsars make a GPS for the cosmos

[REEVES Paul]

Some of them might be...  you could certainly speculate that any culture 
that has attained sufficient technology to make interstellar travel possible 
(and need navigation beacons) would probably have sufficient power to 
'engineer' the occasional neutron star into the correct configuration.
Of course, if 'your' local star happens to be the one they need.. you 
just have to hope they are not Vogons :-)

regards,
Paulg8gja

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Max Robinson
Sent: 26 September 2013 08:23
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Pulsars make a GPS for the cosmos

I remember when pulsars were first discovered one speculation was that they
were interstellar navigation beacons established by intelligent life forms.

Regards.

Max.  K 4 O DS.

Email: m...@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Woodworking site
http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html
Music site: http://www.maxsmusicplace.com

To subscribe to the fun with transistors group send an email to.
funwithtransistors-subscr...@yahoogroups.com

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To subscribe to the fun with wood group send a blank email to
funwithwood-subscr...@yahoogroups.com

- Original Message -
From: Tim t...@skybase.net
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Wednesday, September 25, 2013 7:38 PM
Subject: [time-nuts] Pulsars make a GPS for the cosmos


 Hi all,

 With all the recent talk of clocks etc in spacecraft I though you guys
 might like this...

 http://www.csiro.au/en/Portals/Media/Pulsars-make-a-GPS-for-the-cosmos.aspx

 regards

 Tim

 --
 VK2XAX :: QF56if23 :: BMARC :: WIA

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Re: [time-nuts] HP5065B !!!

[REEVES Paul]

I rather agree with Bruce. What I have seen on recent improvements on laser 
diode accuracy/stability results seem to imply a rather large improvement is 
possible - and, as the HP5065A is a rather rare beast indeed on this side of 
the Atlantic, the excellent work done by Corby is not of direct relevance 
(except to prompt much experimenting..). Trying a stabilised laser diode 
source (and sacrificing one of my 'definitely not HP level' Rb units), in my 
particular case, seems like a very good alternative line of enquiry - even if I 
don't get quite as good results it will be fun!

regards,
Paul
G8GJA

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of paul swed
Sent: 30 April 2013 01:38
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] HP5065B !!!

I have to agree that the subjects really drifted. I am very excited about
what seems like a reasonable effort to improve the 5065. Since I have one
all the more interest. So I want to hear about the reflectors and
concentrators and how they were added and then how the system may have been
retuned to leverage the change.
Have I accidently gotten on to the wrong thread?? If so can some one please
point me to the correct thread?
Thanks
Paul
WB8TSL



On Mon, Apr 29, 2013 at 6:30 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz
 wrote:

 Since performance improves as the bandwidth of the lamp spectrum
 decreases its not unreasonble to suggest that a suitable laser source may
 improve performance further.

 The following paper (and theoretical considerations) indicate that your
 conclusions regarding the potential performance of a laser pumped rubidium
 standard are incorrect.

 http://tf.boulder.nist.gov/**general/pdf/1219.pdfhttp://tf.boulder.nist.gov/general/pdf/1219.pdf

 The addition of second harmonic traps tuned to the 2nd harmonic of the
 modulation frequency of the resonance interrogation signals should improve
 the performance considerably.


 Bruce


 ewkeh...@aol.com wrote:


 I am still sitting here trying to figure out the purpose  of posting the
 article on laser diode pumping of the Rb. One look at the data  and it is
 clear that Corby's work far surpasses the data shown in the paper. All
  it does
 is distract from Corb's accomplishments. Lets be clear, Corby has opened
 the door of H Maser performance for those that have a HP 5065A. Not all
 work
 is  done but a giant step has been accomplished, the challenge now is to
 continue  the work. In simple terms it gets down to keep the A/V slope
 from
 turning  upward. Work is going on off list to address some of the issues
 and
 maybe some  one is willing to contribute. But what the list at a whole
 can do
 is contribute  data as to HP 5065A performance. There are quite a few
 5065A's
 out there but  very little data besides HP spec. To better tackle the
 flattening of the curve,  aging, temperature sensitivity, barometric
 pressure
 sensitivity and even  humidity sensitivity has to be understood. It is
 unrealistic to get past 1 E-13  unless this is understood and compensated
 for. Also
 some of these parameters  will vary from unit to unit and some degree of
 tailoring to a particular unit  has to be considered in the design. Some
 tests
 have to be done by those members  that have access to a Maser.
 Also Corby  found out that units with older A3 modules did not get the
 performance boost but  replacement of A3 did get the super performance.
 That
 confirms my suspicion that  there is room for work on frequency
 generation. PRS
 10 does a direct  frequency generation. Somehow using the  step recovery
 diode as a mixer obviously works but is it optimum, or is there a  better
 way
 to generate the resonator frequency? What is key to get the best  signal
 and
 S/N ratio?
 When previously mentioning aging control, concern was  voiced as to
 getting
 in to the HP 5065A. Corby's work gets to the hart of the  unit, the RVFR,
 but Corby has gone four for four.  Adding control will only move the two C
 field wires to the analog board and using 30 mA from the unit. Unit can
 easily  restored to its original condition as far as frequency control is
 concerned.
 Obviously the RVFR is the big differentiator in the  HP5065A and I know of
 no commercially available unit that even gets close but  once the work is
 complete a look at a FRK may be in order, I doubt it will ever  be as
 good,
 but there is room for a filter and the physics part is considerable
  larger
 than today's units.  Some  other units may be using a filter but the
 physics
 package is so small that  compromises had to be made and the goal was more
 cost than ultimate performance.
 It is up to the list to turn this in to a Maser like  performance with out
 mortgaging your home.
 Bert Kehren
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Re: [time-nuts] Brooks Shera ASM release

[REEVES Paul]

Bert,
I certainly appreciate all the work that has gone into the latest code. I 
learnt a lot from Brook's original (1.33) and modified it to suit my 'peculiar' 
hardware. I've only had time for a short look at the latest but I'm sure there 
is MUCH to learn here too. A very well written program with good commenting - 
not often seen nowadays.
Many thanks to all involved.

regards,
Paul Reeves   G8GJA


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of ewkeh...@aol.com
Sent: 15 April 2013 20:18
To: time-nuts@febo.com
Subject: Re: [time-nuts] Brooks Shera ASM release

Alan
You may suggest something to time nuts, looking at the response I doubt it
and ask my self why did three of us spend three weeks to fully check it out
and  fix some of the code. Will reflect future projects.
Bert Kehren


In a message dated 4/12/2013 8:39:40 P.M. Eastern Daylight Time,
alan.me...@btinternet.com writes:

Bert is  there any way we can add our names to some expression of thanks to
his  widow Karen and her helpers for their work and maybe leave a
remembrance
of his worldwide friends for his family?

Thanks for your  efforts
Best wishes
Alan Melia  (G3NYK)
UK


-  Original Message -
From: ewkeh...@aol.com
To:  time-nuts@febo.com
Sent: Friday, April 12, 2013 8:52 PM
Subject:  [time-nuts] Brooks Shera ASM release


 The time-nuts server  takes out all spaces so allow me to  resend the
  acknowledgementsBert Kehren
  
   


 At this time I like to thank  Brooks for all  the work he did, his wife
 Karen Stoll for  deciding to release HEX and ASM and  Bob Leichner who
 implemented  the software commands. Brooks did not have the  chance to
put
  final
 touches in and complete his work, so Richard McCorkle   stepped in and
made
 the
 final changes. For almost a decade  Brooks and Richard  collaborated on
the
 GPSDO, which benefits all  of us. Also major recognition has  to go to
 Juerg
 Koegel  an other time nut that put our other projects on hold to  check
  every
 iteration. Attached is part of a test that clearly shows  the
performance
 of
 the Alpha filter. Limited by  attachment size contact me off list  for
more
 data.
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Re: [time-nuts] Brooks Shera ASM release

[REEVES Paul]

Hmmm,  apostrophe slip - apologies to any grammar-nuts amongst the 
time-nuts..

regards,
Paul R

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of REEVES Paul
Sent: 16 April 2013 08:07
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Brooks Shera ASM release

Bert,
I certainly appreciate all the work that has gone into the latest code. I 
learnt a lot from Brook's original (1.33) and modified it to suit my 'peculiar' 
hardware. I've only had time for a short look at the latest but I'm sure there 
is MUCH to learn here too. A very well written program with good commenting - 
not often seen nowadays.
Many thanks to all involved.

regards,
Paul Reeves   G8GJA


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of ewkeh...@aol.com
Sent: 15 April 2013 20:18
To: time-nuts@febo.com
Subject: Re: [time-nuts] Brooks Shera ASM release

Alan
You may suggest something to time nuts, looking at the response I doubt it
and ask my self why did three of us spend three weeks to fully check it out
and  fix some of the code. Will reflect future projects.
Bert Kehren


In a message dated 4/12/2013 8:39:40 P.M. Eastern Daylight Time,
alan.me...@btinternet.com writes:

Bert is  there any way we can add our names to some expression of thanks to
his  widow Karen and her helpers for their work and maybe leave a
remembrance
of his worldwide friends for his family?

Thanks for your  efforts
Best wishes
Alan Melia  (G3NYK)
UK


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Re: [time-nuts] GPS antenna??

[REEVES Paul]

That's odd, I'm sure we are using one here - and have been for quite a few 
years. It was used to supply gps signals to buoy systems which were being 
tested indoors. I seem to recall it was a bit 'hit and miss' and suffered from 
multipath problems (but it was set up by the sonar guys who don't know any 
better.). Similar devices were shown at the NPL recently during a seminar 
on gps jamming/mitigation so they are still around.

Paul Reeves,   G8GJA

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Rob Kimberley
Sent: 09 April 2013 12:51
To: 'Tom Van Baak'; 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] GPS antenna??

Unfortunately, (I think this is still valid in the UK), we are not allowed
to use GPS re-radiators. I need to check latest rules  regs.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Van Baak
Sent: 08 April 2013 22:12
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS antenna??

Alan,

Google for words like GPS re-radiator or GPS repeater. There are also units
on eBay. If not to buy, at least to study examples.

The one I have is made by www.gpssource.com but it seems you could build one
yourself. It's easy to test by looking at your indoor SV count and reception
levels. With patch antennae you don't have to worry about RHCP issues,
right?

/tvb

- Original Message -
From: Alan Melia alan.me...@btinternet.com
To: time-nuts measurement time-nuts@febo.com
Sent: Monday, April 08, 2013 9:59 AM
Subject: [time-nuts] GPS antenna??


 Hi all an interesting problem you may have encountered, I want to use a
GPS
 frequency standard inside a building with no opening windows (opening
 windows are known as air conditioning in the UK :-))  )
 This is part of a two day amateur microwave conference so we should have
the
 expertise.

 I intend to try and pass the signal through a a double glazed glass window

 unit (hopefully not metalised) using a couple of patch antennas. The outer

 GPS antenna is active so will need  a 5v supply via an inserter. Inner
patch
 active, outer patch passive to avoid problems of feedback. Main antenna
can
 be shielded from the coupling either physically or with a slab of
 absorber.

 Has anyone tried this? does it work?.any gotchas?

 Thanks
 Alan
 G3NYK


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Re: [time-nuts] eLoran for GPS backup

[REEVES Paul]

Actually it has been on all the time - this is just a more extensive 
implementation of the (formerly experimental) e-loran 'add-in' to target high 
usage areas.

Paul Reeves   G8GJA

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Chuck Forsberg WA7KGX N2469R
Sent: 09 January 2013 08:05
To: ExTek; time-nuts
Subject: [time-nuts] eLoran for GPS backup

The Brits are turning their Loran system back on to protect against GPS
outages from jamming or space weather:

http://www.gpsworld.com/uk-switches-on-eloran-for-backup-in-the-english-channel/

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


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Re: [time-nuts] Comparing PPS from 2 GPS units

[REEVES Paul]

I think not Wireline. That has a rather 'loose' twist coupling between the two 
internal lines. The cable is probably purpose designed for use in delay lines 
and actually did have a helically wound inner conductor. In a previous life 
working for a bit of Marconi that made tv camera systems we used this stuff for 
video equalisation networks and similar. Not sure it is still made as all the 
video processing is digital nowadays..   I might have some stashed away but 
it would take a LOT of finding :-)

regards,
Paul G8GJA

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Gerhard Hoffmann
Sent: 18 December 2012 08:24
To: time-nuts@febo.com
Subject: Re: [time-nuts] Comparing PPS from 2 GPS units

Am 18.12.2012 03:01, schrieb David:
 That is the stuff but Tektronix had some with an even smaller
 diameter.  It would be nice to have a new source as I would hate to
 cannibalize oscilloscopes for it.

Could be Sage Wireline. Also used for couplers and RF power amps.

http://www.google.de/url?sa=trct=jq=sage%20wirelinesource=webcd=9cad=rjaved=0CHwQFjAIurl=http%3A%2F%2Fwww.wtel.com.cn%2Fmanageweb%2Fwebedit%2Fuploadfile%2FSage%2520Catalog%2520Products%25202010.pdfei=mCbQUMy3FMTKsgbs64HYDAusg=AFQjCNGNWELj8YsRHE8scZewoWT_MnrMiA

(I wonder if this monster link works)

regards, Gerhard



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Re: [time-nuts] Nifty MINI TIC for DMTD work

[REEVES Paul]

and one more for the list!

regards,
Paul

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of ewkeh...@aol.com
Sent: 19 November 2012 19:53
To: time-nuts@febo.com
Subject: Re: [time-nuts] Nifty MINI TIC for DMTD work

Don
lets see how much interest and which counter and in the 2 channel it is 3
PIC's and 1 G/A and the 4 channel 5 PIC's and 2 G/A. Easy to solder Juerg
and I  are 70+ so soldering is a key consideration
Bert Kehren.



In a message dated 11/19/2012 2:48:39 P.M. Eastern Standard Time,
d...@montana.com writes:

uh, ok,  how do we order the boards?
Don L

cdel...@juno.com

  MINI-TIC for DMTD work


 Hi Everyone!

  I've been testing a Miniature 2 channel TIC that Bert Kehren and Juerg
  Koegel
 and Richard Mc Corkle have designed.

 It has 9  digits/Sec. and with a 1HZ offset in the DMTD unit gives a
 resolution  of 1X10-15th  at 10 MHz, 2X10-15 with a 5 MHz input, when
  measuring
 Allan deviation. The 200 MHz version doubles the  resolution.

 Of course the baseline performance of the DMTD  unit and the stability of
 the DMTD reference determines the actual  accuracy you can obtain.

 (My dual mixer has a baseline of  approx. 8X10-14th at 1 second and my
 best reference is  4X10-13th  at 1 second.)

 The MINI takes a 5 or 10 MHz reference that  only has to be stable to
 parts in 10-8th/sec.
 I used a neat  14PIN ovenized DIP clock chip I got on eBay and recently
 discussed on  the list.

 The reference is multiplied to 100Mhz for use as the  counters clock.

 The MINI is about 2.5 by 2 inches and has  only 5 chips. Two opto
 couplers an
 op amp for two analog  channels are also on the board. If run on 5 volt a
 3.3 V
  regulator is also on the board. Power required is +5VDC 0.05 A  and  +-
 12

 (for the RS232 interface)

 It  also has two pins you can individually ground to measure the period
  of
 the beat
 note from either channel.

 This  allows you to adjust the offset frequency quickly and  accurately.

 I installed the MINI into a 1U chassis with the  power supply and also
 added heartbeat LEDS for each channel to show  the presence of the 1PPS
 inputs.

 I have plotted  several Rubidium and many Quartz using the MINI
 simultaneously with  a SR620 counter/timer. The plots are identical! So
 much
 so  that I am going to retire and sell my SR620!

 I understand  work is complete on a 4 channel counters and Bluetooth
  interface,
 and work is ongoing on a LCD.

 The MINI  material cost is less than $25.00 depending on how many
 boards are  ordered!

 Resoution based on clock frequency and beat  frequency:

 Carrier[MHz]  Beat [Hz]  HeterodyneTIC [ns]   Resolution
  10101.00E+06101.00E-14
 1011.00E+07101.00E-15
  1011.00E+0755.00E-16
 10101.00E+0655.00E-15
  5105.00E+05102.00E-14
 515.00E+06102.00E-15
  515.00E+0651.00E-15
 5105.00E+0551.00E-14
  
 Woman is  53 But Looks 25
 Mom reveals 1 simple wrinkle trick that has angered  doctors...
  http://thirdpartyoffers.juno.com/TGL3141/50aa82cb1214a2ca03f8st04duc
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--
Neither the voice of authority  nor the weight of reason and argument
are as significant as experiment, for  thence comes quiet to the mind.
De Erroribus Medicorum, R. Bacon, 13th  century.
If you don't know what it is, don't poke it.
Ghost in the  Shell


Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six  Mile Road
POB 134
Huson, MT, 59846
VOX  406-626-4304
www.lightningforensics.com
www.sixmilesystems.com



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Re: [time-nuts] Lady Heather on a Laptop

[REEVES Paul]

atom based mini-ITX boards are available from ~60GBP (low-end, ~1.2GHz) to 
about ~140GBP (dual-core + loads of I/O). Not looked recently as I've got all I 
need (at the moment). Situation your side of the pond should be similar. 
Not expensive.

regards,
Paul
G8GJA

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of paul swed
Sent: 27 September 2012 16:01
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather on a Laptop

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

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

 I have an Intel Atom powered box that runs Linux.  These Atom CPUs use
 so little power they don't put fans on the CPU heat sinks.  I run
 VMware on Linux and then Windows XP inside the virtual PC.  LH runs on
 Windows in the virtual machine.  I have removed the monitor, keyboard
 and mouse.  The entire setup uses about 5 or 6 watts of power

 If I want to see the LH display I can log into the linux system for
 any other computer and have the screen exported.

 Chris Albertson
 Redondo Beach, California

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Re: [time-nuts] FE5680 missing PPS soln

[Reeves Paul]

9mA

PaulG8GJA 

-Original Message-
From: Attila Kinali [mailto:att...@kinali.ch] 
Sent: 03 February 2012 12:55
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE5680 missing PPS soln

On Fri, 3 Feb 2012 09:50:52 -
Rob Kimberley robkimber...@btinternet.com wrote:

 Mine was a green LED out of the junk box, but I did use 330R in 
 series. 1k8 seems rather large.

Then i'm not surprised that your FE-5680 refused to work :-)

Just calculate: 5V supply, approx 2V LED voltage - 3V over the resistor.
3V/330R = 90mA. As i wrote already, the 74AC240 has it's absolute maximum
rating at 50mA. For a general logic output, i wouldn't recomend to draw more
than 10mA (as Bob Grant wrote, the lock signal doesn't seem to pass trough
the 74AC240). Hence, i would say that 330R seems rather small :-)

Keep in mind that you drove circuit at over current for quite a long time.
The circuit is most likely damaged (if they dont have an over current limit,
which i doubt). If for an unknown reason the lock signal fails in the
future, it might be due to this.

Attila Kinali
--
The trouble with you, Shev, is you don't say anything until you've saved up
a whole truckload of damned heavy brick arguments and then you dump them all
out and never look at the bleeding body mangled beneath the heap
-- Tirin, The Dispossessed, U. Le Guin

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Re: [time-nuts] The GPS navigation is the weakest point,

[Reeves Paul]

 I seem to remember a recent 'jamming' trial off the east coast of England
that didn't kill the GPS but did shift the position of the ships involved -
certainly enough to get them aground or to hit something if they weren't
paying attention. I think one showed up inland - which should have been
suspicious! Sorry, cannot remember the reference but was mentioned in GPS
World, I think.

Paul Reeves G8GJA

-Original Message-
From: gary [mailto:li...@lazygranch.com] 
Sent: 15 December 2011 23:45
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] The GPS navigation is the weakest point,

I've talked to the GPS jammers at Nellis and have seen their gear. They
don't spoof but just jam. The gear is totally COTS. Some Marconi signal
generator that can generate white noise at the two GPS frequencies. They
have omni or directional antennas. They have an old Russian jammer on hand,
but the Marconi works a lot better.

I've been jammed by them. It is interesting in that the GPS just suddenly
dies. That is, it seems to track given some noise, but you hit a point where
it suddenly gives up. It is the only time I've seen no satellites shown on
the display.

It wouldn't surprise me if a Growler could spoof a GPS, but I have no hard
evidence that it can.

I'm in agreement with they just jammed everything and the thing ran out of
fuel. I have a FOIA somewhere on a Predator crash. With LOS, it just orbits.
In the case of this Predator, it orbited into a mountain near Creech AFB.


On 12/15/2011 3:18 PM, Chris Albertson wrote:
 I bet this drone contains no technology that is not exportable.  Of 
 course they had to think about a crash.

 I also bet it had an inertial nav system as backup to the GPS.   But
 and this is the key to all backups.  You have to know the primary is
 failed.   When you jam GPS the smart way is not to over power it with
 white noise but to first transmit an IDENTICAL signal.  Then very 
 slowly move your stronger signal away from truth until it is sending
 a false signal.   This way the receiver does not know it is being
 jammed.  No I did not just think of this, it's what everyone does.
   But why then if the INS and GPS disagree was there not an alarm?   It
 was likely a low-cost INS that needed periodic updates from a GPS

 I would not rule out that they simply made the drone fly into a big 
 fishing net and dropped it with a parachute in a kind of controlled
 mid air collision.   Heck the US used to capture film cam falling from
 space with big nets

 Chris Albertson
 Redondo Beach, California

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Re: [time-nuts] The GPS navigation is the weakest point,

[Reeves Paul]

Not so sure - it's a light blue colour (presumably undeneath too) so would
not be too visible against blue sky looking up. WW2 PRU Spitfires used the
same paint scheme ('duck egg' blue?), I believe, to get around German visual
obervation.
Could be wrong, shoot me down. :-)

Paul Reeves  G8GJA

-Original Message-
From: Bob Camp [mailto:li...@rtty.us] 
Sent: 16 December 2011 00:31
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] The GPS navigation is the weakest point,

Hi

Hard to detect looking horizontally, pretty easy looking straight up (or
straight down from above it).

Bob


On Dec 15, 2011, at 7:14 PM, gary wrote:

 Kandahar has proven poor opsec since the thing was photographed! I don't
know about the base in Baluchistan.
 
 But even knowing the launch doesn't mean they know when it is on target.
Supposedly the UAS is stealthy, so it would be hard to detect.
 
 
 On 12/15/2011 4:00 PM, J. Forster wrote:
 KISS guys.
 
 Suppose the Iranians had one of their buddies watching the drone base.
 When they saw a drone take off, the guy just called a contact by cell 
 and the Iranians turned on a wide coverage jammer somewhere along the 
 flight path.
 
 From previous incidents and observations, if the drone came into the
 jammed area, it'd lose GPS lock, orbit, and run out of gas and crash. 
 They could easily select a jammer site that was good for recovery.
 
 FWIW,
 
 -John
 
 
 
 
 
 Hi,
 
 Of course, but then when you switch on your transmitter you are on 
 your own. Considering the speed of a drone (700Km/h?) you need a 
 great coverage, so much RF power out.
 
 Easy: Use a dish antenna on the transmitter.
 Very directional with large ampification.
 If using a 'moderate' opening angle, just pointing the dish at the 
 drone by hand will work.
 After starting the system locked to the gps time, once the signal is 
 on the drone, I don't think it matters anymore. (It might not even 
 matter at the start?) The drone will follow the timing of the 
 jammer.
 As the drone will receive all signals from the single transmitter, 
 the relative timing will be fixed.
 Just using a OCXO will have a good enough short time stability to 
 allow the system to work, I would think.
 As the plan is to land or jam the drone within say 10 minutes, long 
 term stability is not that important...
 
 Greetings,
 Pieter.
 
 On Fri, Dec 16, 2011 at 12:22 AM, J. Forsterj...@quikus.com  wrote:
 
 
 
 You could just have a GPS receiver and use that to sync up the jammer.
 
 -John
 
 ==
 
 
 
 To transmit a GPS cluster signal you need a GPS simulator to 
 generate the cluster so even a single transmitter can do this, 
 the relative timing and not the different positions of the 
 transmitters is what
 the
 receiver sees.
 
 When over-powering the real birds you just needs to be close 
 enough
 in
 timing, and it is the location of the target which is of interest.
 
 If this scenario is true... then they have not done their home-work.
 I
 would ask a number of critical questions already from my civilian 
 background.
 
 Cheers,
 Magnus
 
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Re: [time-nuts] The GPS navigation is the weakest point,

[Reeves Paul]

I believe one of our research establishments was experimenting with a
multistatic radar system based on cellphone tower transmissions and did a
very good job of tracking one of the first (if not the first...) 'stealth'
aircraft that the US sent over this way. Certain persons were rather annoyed
when they promptly reported the track of the 'untrackable' aircraft on the
internet. I have played with multistatic systems on auroras and it's
remarkable how much data you can get.

Paul Reeves G8GJA

-Original Message-
From: Jim Lux [mailto:jim...@earthlink.net] 
Sent: 16 December 2011 01:30
To: time-nuts@febo.com
Subject: Re: [time-nuts] The GPS navigation is the weakest point,

On 12/15/11 4:53 PM, Bob Camp wrote:
 Hi

 Radar bounces off the flat sides very nicely 


You are right, it does, but it doesn't bounce BACK towards the observer,
which is what you care about.  Consider a flat plate at a 45 degree angle
from you.  All the radar energy bounces to the side.  Turns out that it's
diffraction from the edges of those sides that's the limiting aspect.


The first stealth planes (e.g. F-117) were all flat surfaces because you
could actually calculate the reflections and make sure you didn't
inadvertently create a corner reflector.

This is one reason that bistatic radar (transmitter and receiver in
different places) is interesting.  You can detect things that have very low
monostatic radar cross section (RCS).  (also, radar transmitters are easy to
shoot at, because they're like a big beacon saying here I am... so put out
a bunch of transmitters and one receiver and have the expensive signal
processing and operators at the receiver, which is entirely passive).

Even better, you can use something benign as an illuminator... Many of us
have used a TV station as a passive illuminator for a bistatic radar, using
your analog TV set as the detector.


Later, as computational horsepower increased, they could make nice swoopy
surfaces with low RCS, and what's more to the point, low bistatic RCS.


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Re: [time-nuts] gravity controlled pendulumn clock?

[Reeves Paul]

Capacitance is, of course, measured in 'jars' as per the 'Admiralty Handbook
of Wireless Telegraphy' (1930 -ish) :-)
 I do use Farads (bits of them, anyway) guys, really.

Paul Reeves   G8GJA

-Original Message-
From: Don Latham [mailto:d...@montana.com] 
Sent: 14 December 2011 21:02
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] gravity controlled pendulumn clock?

OK, it's right most folks (except for NASA, poke poke) do not have to know
the difference between a pound mass and a pound force, or capacitance in ???
etc. The SI units are best for science because they are all tied together
with common ground. OTH, my grandmother's cookie recipe only puts pounds or
is it slugs on me...
Don

Justin Pinnix
 Contrary to popular belief, most of us in the U.S. have heard of the 
 metric system and understand how it works.  Personally, I agree that 
 it is a simpler and superior system.

 But, English is the system we think in.  We know that if a person is 
 300 lbs they need to lose weight, you need to drink 8 cups of water a 
 day, and wish for 70 degree days.  Grandma's cookie recipe uses 1 cup 
 of flour.
  Trying to convince 300 million people to re-learn all of that is a 
 tough sell when there is no obvious advantage to them.  Most are not 
 scientists or engineers and aren't likely to do business with a 
 foreign country.

 Those of us who are scientists and engineers likely use metric at work 
 and English at home.  Is that wrong?  Maybe, but we're smart people 
 and we can deal with it :-)

 It's not like metric is totally absent.  We drink 2 liter cokes and 
 defend
 ourselves with 9mm pistols.   Our cars use mostly metric parts.  Even
 ham
 radio operators, arguably the most jingoistic and set in the past 
 bunch around, get on the 80, 40, and 20 METER bands.

 Furthermore, I've been to some of these countries that supposedly use 
 the metric system.  One of them measured distance between cities in km 
 and speed limits in MPH.  Now THAT was annoying!

 Progressives tried to force Metric on the U.S. in the 1970s and it 
 didn't catch on.  Besides, we've got bigger standardization problems 
 to deal with these days - getting everyone here to speak English!

 On Wed, Dec 14, 2011 at 2:29 PM, shali...@gmail.com wrote:

 I told myself I would stop after my last posts, but I can't help it.

 I do not pretend to know everything, but I am one of the relatively 
 few in my circle of friends with extensive experience with both 
 systems, and after
 26 years here, the imperial system has simply not made a case for 
 itself as far as I am concerned. It is my opinion, and a fact as far 
 as I am concerned, not that it makes it a universal truth in any 
 other frame of reference. Your mileage may vary.

 I agree that the decimal system is a big part of what makes me prefer 
 the metric system. The meter itself is not a superior unit than the 
 inch or the foot to measure anything. But there are other 
 considerations when using one system versus the other.
 Our designers and mechanical engineers here use decimal fractions of 
 an inch in specifying mechanical drawings, but raw metal stock (and
 tools) are
 still only available in 1/4, 1/8, 1/16 (and so on) of an inch 
 dimensions, so most dimensions have to be given with 3 or 4 decimals, 
 and even then they are not always right. When trying to mentally add 
 two, three or four dimensions each with 4 decimals, and one or two 
 digits to the left of the decimal point, it stops being fun and its 
 easy to make mistakes.
 Somehow, that was never an issue when I was designing back in France.
 Most
 dimensions has 2 or 3 significant digits, making the mental juggling 
 much easier.
 That was the reason for my characterization of the imperial system as 
 being more error prone. I never said or implied that it was less 
 precise.
 Precision is a function of the instrument, not the frame of reference.

 In the metric system, screws and wires are referenced by their 
 diameter, not a reference number that requires a table to figure out 
 how big they are. I understand these numbers correspond to something, 
 they are not arbitrary, but while they may simplify some 
 calculations, in everyday tasks, these numbers tend to complicate 
 life instead of simplifying it.
 Here, every designer has tables after tables plastered on their walls.
 In
 France, I do not remember that we needed so many.

 Another small thing I miss is that a liter of water weighs a kg 
 (under reference conditions, I forgot what that was :). Then the 
 specific weight of various materials only has to be known by their 
 density (ratio of specific weight compared to water). It makes all 
 sorts of calculations ( and guestimations) easy.

 But its just my opinion :)

 Didier

 Sent from my BlackBerry Wireless thingy while I do other things...

 -Original Message-
 From: Chuck Harris cfhar...@erols.com
 Sender: time-nuts-boun...@febo.com
 Date: Wed, 14 

Re: [time-nuts] gravity controlled pendulumn clock?

[Reeves Paul]

Oh dear, what have I helped to get going :-) It has certainly been
interesting reading! My point was, as Chuck notes, that the metre, kilogram
etc. are no more 'precise' than a yard, pound etc. being, essentially,
arbitrary units and the 'imperial' units can be defined just as accurately
and in the same way. I will certainly concede that things become
'interesting' when converting between different units outside of the
'metric' system (and the 'metric' system went through several versions -with
distinctly odd units - before the current standardised one) but that just
relates to my comment on the reduction of mental arithmetic abilities
nowadays as against simple decimal point shifting..
I'm not sure I would agree on being 'forced' to take on certain measurements
- we are a lot closer to Europe (sort of...), after all - but pints, inches
and miles do seem more 'natural' (a litre is just too much beer) and you
could never measure a cricket pitch in metres!
That's all from me,

Paul Reeves G8GJA



-Original Message-
From: Chuck Harris [mailto:cfhar...@erols.com] 
Sent: 14 December 2011 02:05
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] gravity controlled pendulumn clock?

Arnold Tibus wrote:
 I don't understand at all the arguments against the metric system and 
 the polemic remarks about. I second the statements of Neville and Jim.

 Without these intelligent french Astronomers like Jean-Baptiste-Joseph 
 Delambre, Pierre-François-André Méchain and J.J. Lalande (more infos:
 Ken Alder, The Measure of All Things), we would still have the severe 
 problems they had centuries ago!

 Reading WIKIPEDIA, http://en.wikipedia.org 
 /wiki/German_units_of_measurement,
 we find a good example of weird units (just for only a part of Germany):

 Before the introduction of the metric system in Germany, almost every 
 town had its own definitions of the units shown below, and supposedly 
 by 1810, in Baden alone, there were 112 different standards for the 
 Elle around Germany. The metric system was a much-needed 
 standardisation in Germany.

 This was not only a german problem, and we still have today some 
 problems in the world in this area.

Standardization is fine.  Attempting to force the world's largest economy to
bend to the wishes of Europe isn't fine.  The US system has been
standardized for more than a century, and works very nicely.  Decimal
inches, decimal pounds, and seconds is every bit as valid a measurement
system as the equally arbitrary meter, kilogram and second.  Decimal inches,
decimal pounds, and seconds flies most of the airframes in the world, won
WWII, and took mankind to the moon and beyond.

Saying that the use of pounds, and yards is imprecise is simply ignorant.


 I believe we should think more about what we are saying and doing, so 
 we would do a big step forward to become a world community. ...

Regardless of our measurement systems, we are already a world community.

The strife we see in the world today is not the result of measurements, but
rather is the result of religion, politics, and culture.

-Chuck Harris

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Re: [time-nuts] gravity controlled pendulumn clock?

[Reeves Paul]

But it is 1 chain, (22 yards), surely? And you admitted that is not 20m when
laid out properly. The laws of cricket have not changed (even if they give a
metric equivalent) just because we might have joined the EU!! I have no
objection to using a metric measure to do it but you have to use a
non-integer value - and do the conversion. Not very elegant. So if tape
measures with joint metric/imperial markings are available - and they are -
why not use the correct measure in the first place? 
As to the definition of the inch it works both ways - why have 25.4
subdivisions of an arbitrary length to equal one inch. Just use an inch -
it's no less valid and the yard/metre can both be defined in exactly the
same way as so-and-so many wavelengths of Kr86 light. As I said, it's just
that the internal standards conversions in the 'metric' system are easier.
Just nit-picking, really. I use both systems happily as, I suspect, most
people of my age do, depending on circumstance.

Paul Reeves  G8GJA


-Original Message-
From: Jim Palfreyman [mailto:jim77...@gmail.com] 
Sent: 14 December 2011 11:23
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] gravity controlled pendulumn clock?

Paul, a cricket pitch is 20 m. Sure when the curator draws the lines it is
12cm longer, (and I guarantee s/he uses a metric measure) but when we pace
it out for backyard cricket - its 20 m.

Also my American friends, all your imperial measurements are DEFINED in
terms of metric. eg your inch is 25.4 mm exactly. By definition. It has been
estimated you could save a trillion dollars a year in your economy by
converting - which you will ultimately do. I just hope it is in my lifetime.

On Wednesday, 14 December 2011, Reeves Paul paul.ree...@uk.thalesgroup.com
wrote:
 Oh dear, what have I helped to get going :-) It has certainly been 
 interesting reading! My point was, as Chuck notes, that the metre,
kilogram
 etc. are no more 'precise' than a yard, pound etc. being, essentially, 
 arbitrary units and the 'imperial' units can be defined just as 
 accurately and in the same way. I will certainly concede that things 
 become 'interesting' when converting between different units outside 
 of the 'metric' system (and the 'metric' system went through several 
 versions
-with
 distinctly odd units - before the current standardised one) but that 
 just relates to my comment on the reduction of mental arithmetic 
 abilities nowadays as against simple decimal point shifting..
 I'm not sure I would agree on being 'forced' to take on certain
measurements
 - we are a lot closer to Europe (sort of...), after all - but pints,
inches
 and miles do seem more 'natural' (a litre is just too much beer) and 
 you could never measure a cricket pitch in metres!
 That's all from me,

 Paul Reeves G8GJA



 -Original Message-
 From: Chuck Harris [mailto:cfhar...@erols.com]
 Sent: 14 December 2011 02:05
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] gravity controlled pendulumn clock?

 Arnold Tibus wrote:
 I don't understand at all the arguments against the metric system and 
 the polemic remarks about. I second the statements of Neville and Jim.

 Without these intelligent french Astronomers like 
 Jean-Baptiste-Joseph Delambre, Pierre-François-André Méchain and J.J.
Lalande (more infos:
 Ken Alder, The Measure of All Things), we would still have the severe 
 problems they had centuries ago!

 Reading WIKIPEDIA, http://en.wikipedia.org 
 /wiki/German_units_of_measurement,
 we find a good example of weird units (just for only a part of Germany):

 Before the introduction of the metric system in Germany, almost 
 every town had its own definitions of the units shown below, and 
 supposedly by 1810, in Baden alone, there were 112 different 
 standards for the Elle around Germany. The metric system was a 
 much-needed standardisation in Germany.

 This was not only a german problem, and we still have today some 
 problems in the world in this area.

 Standardization is fine.  Attempting to force the world's largest 
 economy
to
 bend to the wishes of Europe isn't fine.  The US system has been 
 standardized for more than a century, and works very nicely.  Decimal 
 inches, decimal pounds, and seconds is every bit as valid a 
 measurement system as the equally arbitrary meter, kilogram and 
 second.  Decimal
inches,
 decimal pounds, and seconds flies most of the airframes in the world, 
 won WWII, and took mankind to the moon and beyond.

 Saying that the use of pounds, and yards is imprecise is simply ignorant.


 I believe we should think more about what we are saying and doing, so 
 we would do a big step forward to become a world community. ...

 Regardless of our measurement systems, we are already a world community.

 The strife we see in the world today is not the result of 
 measurements,
but
 rather is the result of religion, politics, and culture.

 -Chuck Harris

Re: [time-nuts] gravity controlled pendulumn clock?

[Reeves Paul]

...and just what is 'less accurate' about pounds, feet, cubic yards etc?
The metric system (I use the term loosely) is ideal for those people who
cannot do mental arithmetic and can only shift decimal points. All
'imperial' measurements can be defined just as the metre, kilogramme (and
there is a dodgy one...)can be.
Remember that the metre is originally based on (very) inaccurate French
surveying techniques, a yard would do just as well. As a (somewhat
middle-aged) physicist I'm perfectly happy with either system - although the
imperial system is obviously better :-)  . Just look what happened when NASA
tried to use metric measurements for that Mars probe..
And does it really matter anyway?

Paul Reeves,   G8GJA 

-Original Message-
From: Jim Palfreyman [mailto:jim77...@gmail.com] 
Sent: 13 December 2011 09:28
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] gravity controlled pendulumn clock?

Gentlemen, gentlemen and gentlemen!

We are time-nuts. Accuracy is paramount. We are scientists.

Please steer clear of pounds, feet, cubic yards and other such rubbish.

Scientists speak in metric and so should you.

Please.

Jim


On 13 December 2011 16:24, Don Latham d...@montana.com wrote:



 or you can use a cubic yard of plain sand, about 2700# (depends on 
 how
 moist it is)
 --
 Neither the voice of authority nor the weight of reason and argument 
 are as significant as experiment, for thence comes quiet to the mind.
 R. Bacon
 If you don't know what it is, don't poke it.
 Ghost in the Shell


 Dr. Don Latham AJ7LL
 Six Mile Systems LLP
 17850 Six Mile Road
 POB 134
 Huson, MT, 59846
 VOX 406-626-4304
 www.lightningforensics.com
 www.sixmilesystems.com



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Re: [time-nuts] Frequency counter recommendation

[Reeves Paul]

It's OK for you guys in the USA with lots of old HP gear around but for us
over the other side of the pond we can only dream of those sort of surplus
quantities - let alone the prices   Still, it's nice to dream.
A 'purpose built' design of a front end might well have quite a few people
interested over here.

Paul Reeves  G8GJA

-Original Message-
From: jimlux [mailto:jim...@earthlink.net]
Sent: 19 December 2010 04:08
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Frequency counter recommendation


Bob Camp wrote:
 Hi
 
 If you are going to do a full boat implementation and work out all the
isolation issues and packaging, the question becomes:
 
 Will it be better bang for the buck than a ~ $200 HP 5370?


Isn't that the classic New vs Used discussion, though?  Those 5370s 
won't be available for $200 all the time

The used equipment dealers charge more like $750-2k for that, depending 
if it's an A or a B, or if it's calibrated, etc.  The lowest price on 
eBay is around $700

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Re: [time-nuts] Time of death-Again

[Reeves Paul]

I think you may be thinking of 'Dark Star', not too sure (been a while since
I last saw it)about the bomb (bomb number 20 with a mind of its own) but
one of the crew attempted re-entry on a surfboard  :-)

Paul   g8gja

-Original Message-
From: d.sei...@comcast.net [mailto:d.sei...@comcast.net]
Sent: 28 October 2010 10:13
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Time of death-Again


Wasn't there a sci-fi movie with a similar scene? (guy riding bomb, but in
space) I know I've seen it, but can't place it. 


Dave 
- Original Message - 
From: Michael Conlen michael.con...@ncf.edu 
To: Discussion of precise time and frequency measurement
time-nuts@febo.com 
Sent: Wednesday, October 27, 2010 9:42:11 PM 
Subject: Re: [time-nuts] Time of death-Again 

Remember though, they were flying low to stay under radar and evade the 
enemy while going for their secondary target because they couldn't reach the

first. They dropped from a pretty low target, and probably didn't care since

as far as they could tell the world wasn't going to be worth living in if 
they got back. 

On Wed, Oct 27, 2010 at 6:51 PM, Perry Sandeen sandee...@yahoo.com wrote: 

 Gents, 
 
 Wrote:  If you want a sub-microsecond time of death, sit on a bomb like 
 Major T. J. King Kong in Dr. Strangelove, and get your friends to time

 and triangulate the prompt radiation. That should be good to a few 10's of

 nanoseconds. 
 
 Absolutely Not So! 
 
 The H-Bombs are slowed by parachutes so the bomber can get away. The 
 outside temperature for a B-52 at operating altitude over Russia would 
 likely be at least minus 60 degrees F. 
 
 Major T, since he was wearing an indoor uniform, would become a solid
block 
 of ice before the bomb went off so his TOD has a variance of time between 
 when became a solid chunk of ice and the time of instant defrosting. This 
 could be 30 to 60 seconds. Totally un-acceptable accuracy for even the 
 cadet grade newbe time-nut ;) 
 
 Why, anyone accepting such an error would have to answer to the Coca Cola 
 company distributor at Burpelson Air Force Base. 
 
 Carpay Diem, Carpell Tunnel-Whatever 
 
 Regards, 
 
 Perrier 
 
 
 
 
 
 
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Re: [time-nuts] Pulsars (was: 60 KHz Receiver)

[Reeves Paul]

Receiving setup - pretty standard amateur eme/radio astromony  kit, good
antenna, LNA, downconverter. Antenna choice depends on frequency, pulsars
are broadband but generally 300 MHz to as many GHz as you can build an LNA.
Amateur attempts seem to be 406, ~600, ~1400MHz. 3m dish minimum or
equivalent yagi arrays (better at lf end). Bandwidth of a few 10s of KHZ or
more - there are trade-offs due to dispersion, high frequencies travel
faster than the low ones so the pulse form is 'spread' but signal levels are
higher at the lower frequencies. De-dispersion can be done in dsp but
probably not real time unless you have lots of cpu power. Best pulsars for
timing would seem to be be the millisecond ones but these are seriously
faint. For getting the signal out of the noise a gated sampling approach is
used locked to the repetition rate and divided down (so a system can be
theoretically used for any pulsar) and driven from a Rb source or better
(the pros use H-masers). There are lists of these things - try CSIRO in
Australia, they have a good on-line database. The Japanese have looked at
pulsars as a replacement for national standards but not sure of the results.
They are (naturally...) slowing down but should be good for a while yet ;-)

regards,
Paul Reeves   G8GJA


-Original Message-
From: Hal Murray [mailto:hmur...@megapathdsl.net]
Sent: 05 October 2010 07:30
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Pulsars (was: 60 KHz Receiver)



jim...@earthlink.net said:
 If you want something that isn't run by governments,and is a technical
 challenge, how about pulsars?   I'd guess (not having looked into it at
 all) that is would be cheaper to set up a station to receive pulsars  than
 to run a Cs standard. 

What sort of gear does it take to hear a pulsar?

What sort of spectrum are they sending?  What frequencies would I listen to?

What sort of bandwidth would the receiver use?

If I have a setup that can hear Pulsar A, will it also be useful for Pulsar
B 
and C and ...?  Or do I need to listen on widely different frequencies?


One problem with pulsars is that they might go below the horizon for part of

the day.

Is there a convenient one up near the north pole?

I assume that they are weak enough that I need a steerable dish.  Is there a

catalog of pulsars that might be interesting to use for amateur timekeeping?

I assume a strong signal would be the primary consideration.

Any chance of hearing one without a dish?


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




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Re: [time-nuts] PICTIC II

[Reeves Paul]

And here is a request for yet another, to keep the price down :-)

regards,
paulg8gja

-Original Message-
From: Stanley Reynolds [mailto:stanley_reyno...@yahoo.com]
Sent: 01 July 2010 16:42
To: time-nuts@febo.com
Subject: Re: [time-nuts] PICTIC II


The price would be at my cost and actual shipping, no packaging or
processing 
charges added by me. Not sure of price till I have the number of boards but
hope 
as a group we will get a better price. This would also allow us to order
just 1 
if that is the need. I can take paypal but that has their cost as well. I
would 
not expect money till I've received the boards and I'm ready to ship. 


Stanley

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Re: [time-nuts] Frequency divider PCB: Current status on pre-ord ers, and pointers to documentation.

[Reeves Paul]

Hello David,

Could you add me to the list for one board please?

regards
Paul Reeves G8GJA

-Original Message-
From: David C. Partridge [mailto:david.partri...@dsl.pipex.com]
Sent: 17 March 2010 18:28
To: teksco...@yahoogroups.com; tekscop...@yahoogroups.com;
hp_agilent_equipm...@yahoogroups.com; testequiptra...@yahoogroups.com;
'Discussion of precise time and frequency measurement'
Subject: [time-nuts] Frequency divider PCB: Current status on
pre-orders, and pointers to documentation.


The current situation is that I have almost enough statements of intent to
get to the magic 50 which will allow a price of GBP14.50 per board plus
delivery.   For the avoidance of doubt, this is the price for a bare PCB,
not for a kit, and definitely not for a made up board.

I intend to keep the book open until 18:00 Zulu (UTC or GMT) on Sunday
21st March, I will then count up what I have and order that many boards (and
maybe a few over to get a nice round number).

I've received numerous reqeusts for the design documentation, schematic, and
a bill of materials

They can all be downloaded from my website, but there's no way (yet) to
navigate to them (a round tuit problem).

Write up:

http://www.perdrix.co.uk/FrequencyDivider/Frequency%20Divider%202.pdf

Schematic:

http://www.perdrix.co.uk/FrequencyDivider/Frequency%20Divider%202%20Schemat
ic.pdf 

and BOM:

http://www.perdrix.co.uk/FrequencyDivider/Frequency%20Divider%202%20Bill%20
of%20Materials.pdf

The schematic and write up have both been updated today, and the BOM is new
today.

For those who worry about SMT soldering, you don't need a reflow oven, it
can all be done with tweezers, a small tipped iron, fine solder wire, and
liquid flux (or a flux pen).  A good pair of strong reading glasses helps
too!   See:

http://www.curiousinventor.com/guides/Surface_Mount_Soldering/101

I've also had questions on part pricing:  Back in 2008, the cost to populate
one PCB using a MAX999, thick film resistors, and standard (X7R) chip
capacitors was about GBP28 including Molex headers and SMB sockets.   I
don't expect it to be massively different now.   I'm afraid I don't have
full parts kits, and the necessary up front costs to do so is more than my
finances allow at present.

FWIW, the ADCMP600 is a bit pricier than the MAX999, and is supposed to be
better, though I'm not sure in what respects it is better.

If you want the lowest possible level of phase noise, you would follow the
bill of materials recommendations and use thin film resistors and C0G
capacitors in the clock shaper part of the circuit at the very least, but
this adds considerably to the cost (for example 100nF C0G 1206 capacitors
are about 1 pound each, while an X7R part is only a few pence).

Regards,
David Partridge


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Re: [time-nuts] Cathodeon TCXOs??

[Reeves Paul]

I'm pretty sure that I have a Cathodeon filter/osc catalogue at home (work
reference material relocated due to constant 'downsizing' of storage space
by my employer - everything is on the internet); I'll check up on it
tonight.

Paul   G8GJA

-Original Message-
From: Alan Melia [mailto:alan.me...@btinternet.com]
Sent: 24 May 2009 20:12
To: time-nuts@febo.com
Subject: [time-nuts] Cathodeon TCXOs??


Hi I wonder if anyone still has a datasheet/catalogue of Cathodeon products.
This firm made crystals and oscillators and filters in the 1980 and 90s in
Cambridge, England. (It is only 50 miles up the raod but I have not been
able to find anyone who still has any knowledge of the products.)

The units are FS5980/01  10MHz
FS5951/315MHz
I think the the 10MHz may be a TCXO,VCTCXO or even an OCXO, but  the 5MHz
does not have enough pins to be other than a TCXO. The spec would be useful
(I think I have that from a previous query) but a pin-out is the vital
information because none of the pins is common to the case, so it is
difficult to work out the connections with an ohm-meter.

Thanks
Alan G3NYK


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Re: [time-nuts] 10 MHz Band-Pass Filter Needed

[Reeves Paul]

Try an old 10MBs Ethernet card - they have a nice packaged filter (contains
2 filters actually, 5  7 pole) which tidies up a 10MHz signal. Package is
'YCL 20F001N' but similar ones may exist. Essentially zero cost. Info from
the UHF-Satcom group.
 cheers,
Paul   G8GJA

-Original Message-
From: Richard W. Solomon [mailto:w1...@earthlink.net]
Sent: 08 January 2009 18:11
To: time-nuts@febo.com
Subject: [time-nuts] 10 MHz Band-Pass Filter Needed


The GPSDO I want to use has an output rich in harmonics. In some
cases that is good, but Murphy rules and in the application I have
today, it is not good.

I need a 10 MHz Band-Pass Filter, Bandwidth is not critical, something
small with SMA connectors would be ideal, but I can live with BNC.

Anyone have such a beast or know where I can get one ? I checked
Mini-Circuits
and choked on the price !!

Thanks, Dick, W1KSZ

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Re: [time-nuts] Sulzer Labs D-5 oscillator

[Reeves Paul]

Hi Tom, all,

Sorry, the D-5 is a rectangular solid, 4x4x7, quite featureless except
for the nameplate on the top and the connection pins, circular ~14pin, octal
size (possibly a valve - sorry, 'tube' - base, on the bottom. I will try to
get a couple of pictures off to the group within the next few days.
I have a 5.0C like the one in the reference - a very nice performing unit,
compares nicely with homebuilt GPSDO and off-air MSF standards. When the 'D'
model was offered by a friend I snapped it up - anything by Sulzer was good!
Apologies for the 'legalese' fluff that appears at the end - my employers
apparently have several lawyers with nothing important to do

regards,
Paul G8GJA


-Original Message-
From: Tom Van Baak [mailto:[EMAIL PROTECTED]
Sent: 10 October 2008 15:17
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator


 Hi all,
 
 I need a bit of help getting an old Sulzer D-5 5MHz oscillator to work. It
 was built into a rack module with monitoring facilities and had been
 slightly 'got-at' by the previous owner. Some of the connections were
 pencilled on the case but not enough to give confidence about powering it
 up. Has anybody got any information on this 'classic' design? Pin
connection
 data would be a great help, anything more would be wonderful!!
 
 Thanks in advance,
 
 Paul Reeves,G8GJA

Does it look like either of these?

http://leapsecond.com/museum/sul25-1/
http://leapsecond.com/museum/sul25-2/

/tvb


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[time-nuts] Sulzer Labs D-5 oscillator

[Reeves Paul]

Hi all,
 
I need a bit of help getting an old Sulzer D-5 5MHz oscillator to work. It
was built into a rack module with monitoring facilities and had been
slightly 'got-at' by the previous owner. Some of the connections were
pencilled on the case but not enough to give confidence about powering it
up. Has anybody got any information on this 'classic' design? Pin connection
data would be a great help, anything more would be wonderful!!
 
Thanks in advance,
 
Paul Reeves,G8GJA

This email, including any attachment, is a confidential communication
intended solely for the use of the individual or entity to whom it is
addressed. It contains information which is private and may be proprietary
or covered by legal professional privilege. If you have received this email
in error, please notify the sender upon receipt, and immediately delete it
from your system.

Anything contained in this email that is not connected with the businesses
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Whilst we have taken reasonable precautions to ensure that any attachment to
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Re: [time-nuts] Which GPS receiver?

[Reeves Paul]

Hello Murray,

The ublox LEA-5T does not have the RAW data output facility of the LEA-4T,
otherwise they are pretty much a drop-in replacement. This might be
significant in some cases (and means I won't be giving up my LEA-4T system
just yet...). I have a -5T on order and it will be interesting to compare
them (they are both the same price). Very nice reliable modules, good
documentation.

73s
Paul,  G8GJA

-Original Message-
From: Murray Greenman [mailto:[EMAIL PROTECTED]
Sent: 10 September 2008 20:57
To: [EMAIL PROTECTED]
Cc: time-nuts@febo.com
Subject: [time-nuts] Which GPS receiver?


Ulrich,

Living where you do, I'd suggest checking out the U-BLOX range of
modules. The model you need is the LEA-5T. The LEA-5 family is
state-of-the-art, and I believe uses an ATMEL DSP software baseband
engine (with reportedly one million correlators!)

I have two of their modules (LEA-5H and LEA-5P) here for evaluation, and
they are impressive. Unfortunately they didn't send me the timing
version!

See http://www.u-blox.com/products/lea_5t.html
and http://www.u-blox.com/products/evk_5t.html

This module has self-survey, single-satellite mode, 15ns timing accuracy
and a configurable time pulse. The easiest (and no doubt most
expensive!) way to deploy this module would be to buy the evaluation kit
EVK-5T, which comes with USB and RS232 interface, active antenna, power
supply and all the software and documentation. From my experience, the
U-BLOX PC support software is excellent.

U-BLOX are based in Switzerland, so more-or-less speak your language.

73,
Murray ZL1BPU


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