Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Giuseppe,
Welcome to the group.
If you are already happy constructing equipment and have basic test gear
('scope, DMM) and a small budget, I'd suggest a timing GPS as a starting point.
While a Thunderbolt will give most of what you want, it is more expensive. A
Timing version or Motorola's Oncore (ebay item 300355981024 from flukel for
instance) will give you an accurate 1 pulse per second output (you also need a
power supply antenna and a PC). This and a 'scope will allow you to calibrate
other instruments and a oven controlled crystal oscillator. A GPS based
solution (including Thunderbolt) will give you good confidence of accuracy.
Just buying a surplus Rubidium could result in you adjusting all your
instruments to the wrong frequency! Like many of these decisions, it's a
balance between time and money, with a lesser input from your capabilities and
existing equipment.
Robert G8RPI.
--- On Mon, 28/12/09, Giuseppe Marullo giuse...@marullo.it wrote:
From: Giuseppe Marullo giuse...@marullo.it
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Monday, 28 December, 2009, 0:56
Thanks a lot to all for your quick answer.
Rubinium should be good for my needs, but buying it surplus makes me think I
could get something very used (and abused) and it does not have the self
correcting thing thunderbolt has.
GPSDO gives me also the time, maybe with a supercool LCD display.
A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also
needs a GPS antenna of some sort.
Do you know exactly the power requirement? On Ebay I read 15W then few mA on
each branch (board only). Something is not clear to me.
The dark side of the noon already embraced I have
Giuseppe
PS: I am experiencing mail problems for the first time in many years, please
anyone willing to contact me directly do cc copy also this other email address:
giuseppe.maru...@iname.com while my ISP gathers back all the bits they lost (2
days of emails vanished from my IMAP account under my eyes, literally)
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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Re: [time-nuts] time-nuts Digest, Vol 65, Issue 103
Hi, 2009/12/27 Bob Camp li...@cq.nu: Tough to beat a self winding quartz wrist watch, unless it's not accurate enough to do what you need to do. And perhaps that's the point we sometimes miss. 73 Steve -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Giuseppe Marullo wrote: Hi all, just subscribed, I would like a quick advice on a 10MHz reference for calibrating my instruments and for fun. In particular, I would like to know if you could give me advice on EFRATOM FRS-A,FRS-C, DATUM LPRO-101, Thunderbolt and such. I would prefer a GPSDO (like the Thunderbolt), but budget is very tight (about 100EUR), so I am searching old surplus stuff on Ebay.snip A timing GPS receiver with a built-in 10MHz oscillator would fit your budget nicely. The Navsync CW12-TIM looks like the obvious choice. You would need the CW12-TIM module, a 3.3V DC supply and a suitable aerial/antenna. Power consumption is well below 1W. It has a 1PPS output with 30ns RMS accuracy and a NCO output with a default output frequency of 10MHz. http://www.navsync.com/docs/CW12-TIM_DS.pdf I paid just over Eur50 for mine last year when the Euro was very strong against foreign currencies. -- Linux 2.6.30 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 65, Issue 103
Hi But being *rational* about all this takes out most of the fun Bob On Dec 28, 2009, at 5:30 AM, Steve Rooke wrote: Hi, 2009/12/27 Bob Camp li...@cq.nu: Tough to beat a self winding quartz wrist watch, unless it's not accurate enough to do what you need to do. And perhaps that's the point we sometimes miss. 73 Steve -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Racal 1992 input amplifier offset problem
Hi, Sorry if this question is a bit out of place. It is not about timing, but more an electronics thing. But searching for Racal 1992 seems to get a lot of hits here on this list. I have just received a used Racal 1992 counter and are checking it for proper operation. All seem fine except the channel A only triggers properly on small signals with DC input or when in auto-trigger mode selecting AC. Checking the trigger level in this mode shows -1.08 (Volts I guess) I went through the protocol for channel-A adjustment with R192/R149 and channel-B adjustment with R193/R150. Channel B seems to work fine and needed only minor adjustment. The offset can be adjusted to 0V and the specified sensitivity levels of 13mV (count) and 7mV (gate off) are fine. Changing from AC to DC has no effect, both work fine here. However channel A seems to have a problem. It is not possible to adjust it to 0V in AC mode. Only with DC it can be adjusted to 0. Sensitivity is also a bit out of range. I get 17mV (count is steady) and 7mV (gate off). The trigger output levels at the back seem ok for both channels (about +5.1 to -5.1) So I guess the DAC is still OK. Looking at the schematics I suspect IC34 (CA3140E) might be having a problem, but I did not dare to open the module yet. Is it placed in a socket? Has anybody experienced a similar problem and fixed it? Are some capacitors known to go bad? Any help would be appreciated. Cheers, Joop ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Robert,
Will the Motorola that You have mentioned give a 10.00 MHz output standard.
Thank You
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Robert Atkinson robert8...@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Cc: giuseppe.maru...@iname.com
Sent: Mon, December 28, 2009 5:14:49 AM
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Giuseppe,
Welcome to the group.
If you are already happy constructing equipment and have basic test gear
('scope, DMM) and a small budget, I'd suggest a timing GPS as a starting point.
While a Thunderbolt will give most of what you want, it is more expensive. A
Timing version or Motorola's Oncore (ebay item 300355981024 from flukel for
instance) will give you an accurate 1 pulse per second output (you also need a
power supply antenna and a PC). This and a 'scope will allow you to calibrate
other instruments and a oven controlled crystal oscillator. A GPS based
solution (including Thunderbolt) will give you good confidence of accuracy.
Just buying a surplus Rubidium could result in you adjusting all your
instruments to the wrong frequency! Like many of these decisions, it's a
balance between time and money, with a lesser input from your capabilities and
existing equipment.
Robert G8RPI.
--- On Mon, 28/12/09, Giuseppe Marullo giuse...@marullo.it wrote:
From: Giuseppe Marullo giuse...@marullo.it
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Monday, 28 December, 2009, 0:56
Thanks a lot to all for your quick answer.
Rubinium should be good for my needs, but buying it surplus makes me think I
could get something very used (and abused) and it does not have the self
correcting thing thunderbolt has.
GPSDO gives me also the time, maybe with a supercool LCD display.
A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also
needs a GPS antenna of some sort.
Do you know exactly the power requirement? On Ebay I read 15W then few mA on
each branch (board only). Something is not clear to me.
The dark side of the noon already embraced I have
Giuseppe
PS: I am experiencing mail problems for the first time in many years, please
anyone willing to contact me directly do cc copy also this other email address:
giuseppe.maru...@iname.com while my ISP gathers back all the bits they lost (2
days of emails vanished from my IMAP account under my eyes, literally)
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Robert, Welcome to the group. Thank you and all the others, you are giving me a lot of informations. BTW, my provider retrieved my emails so I am fully operational (at least I hope). while I did not originally envision building this kind of equipment, I could do it while it lies well within the digital domain, I have some test gear (frequency counter, DMM, analog scope, BF frequency generator, LA and some FPGAs with 100+Msamples ADC) but...I will have to trust it so I am back at square one, until I have a reliable source... I would like a GPSDO, possibly ready to run, then I will start building something that I could actually check against the GPSDO. Maybe a GPSDO myself, who knows...wondering if this could be done all digital, without using a DAC, without using a driving voltage for a OCXO. Giuseppe ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Does the factory sell direct in small quantities ? 73, Dick, W1KSZ -Original Message- From: Eamon Skelton nos...@oceanfree.net Sent: Dec 28, 2009 6:15 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference Giuseppe Marullo wrote: Hi all, just subscribed, I would like a quick advice on a 10MHz reference for calibrating my instruments and for fun. In particular, I would like to know if you could give me advice on EFRATOM FRS-A,FRS-C, DATUM LPRO-101, Thunderbolt and such. I would prefer a GPSDO (like the Thunderbolt), but budget is very tight (about 100EUR), so I am searching old surplus stuff on Ebay.snip A timing GPS receiver with a built-in 10MHz oscillator would fit your budget nicely. The Navsync CW12-TIM looks like the obvious choice. You would need the CW12-TIM module, a 3.3V DC supply and a suitable aerial/antenna. Power consumption is well below 1W. It has a 1PPS output with 30ns RMS accuracy and a NCO output with a default output frequency of 10MHz. http://www.navsync.com/docs/CW12-TIM_DS.pdf I paid just over Eur50 for mine last year when the Euro was very strong against foreign currencies. -- Linux 2.6.30 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Cheap Rubidium (heatpipe cooling for)
Hi With all the dialog on controlling temperature of the Rb unit I decided to take my Frequency Electronics Inc. 5062B apart since the Oven Controlled Oscillator and Rb Physics Package are separate and I may want to replace the oscillator with a HP 10811 that Corby has tested to be better than 1 E 12 from 1 to 100 sec. In order to proceed it would help if any one out there has any information on the circuitry, the unit has two modules and two PC boards. The boards are power supply and synthesizer and the modules are Rb unit and oscillator. I have opened the Rb unit and I am convinced that it can be a candidate for heat pipe cooling. Since it can be operated separate from the rest of the unit it will be possible to measure heat rise. The published plot of a 5600 shows a temp performance of +- 3 E -11 from -5 to +45 C. I am not sure if there is room for improvement. Any help would be greatly appreciated. Bert KehrenWB5MZJMiami In a message dated 12/27/2009 2:18:14 P.M. Eastern Standard Time, li...@cq.nu writes: Hi The tip it and listen to it slam test is a standard way of checking out a triple point of water cell for basically the same reason (you check the vacuum. Of course since a TWP cell is thin glass and not a nice metal pipe, you *may* break the seal by testing it Bob On Dec 27, 2009, at 9:33 AM, Joe Gwinn wrote: At 12:00 PM + 12/27/09, time-nuts-requ...@febo.com wrote: Date: Sat, 26 Dec 2009 17:04:46 -0700 From: Robert Darlington rdarling...@gmail.com Subject: Re: [time-nuts] Cheap Rubidium (heatpipe cooling for) To: Discussion of precise time and frequency measurement time-nuts@febo.com My comments are in-line, below On Fri, Dec 25, 2009 at 4:38 PM, Joe Gwinn joegw...@comcast.net wrote: At 12:45 AM + 12/25/09, time-nuts-requ...@febo.com wrote: Date: Thu, 24 Dec 2009 17:14:38 -0700 From: Robert Darlington rdarling...@gmail.com Subject: Re: [time-nuts] Cheap Rubidium (heatpipe cooling for) To: Discussion of precise time and frequency measurement time-nuts@febo.com On Thu, Dec 24, 2009 at 1:32 PM, Bob Camp li...@cq.nu wrote: Hi A heat pipe might work if the fluid had a sufficiently low boiling point. The working fluid in a heat pipe will boil at every temperature above its melting point. Well, I've been thinking about this, and I used the term heat pipe too loosely. Both the one- and two-pipe systems mentioned here have no wicks, and so technically are two-phase thermosyphons, which depend on gravity to circulate vapor and condensate. A true heat pipe has a wick, and will work in zero gravity. One gets significant heat transfer by phase change so long as the vapor pressure in the heat input end is high enough to generate enough vapor to carry the thermal power flow, and this makes the pipe isothermal. However the temperature (although constant along the pipe) varies with the thermal power flow (in thermal watts) being carried. What I'm looking for is related but different: A device where the heat transfer capacity varies sharply with temperature, so that there is a range of heat transfer rates over which the input-end temperature will be substantially constant. This is why I envision the fluid boiling (versus evaporating), which is actually out of the operating regime of a true heat pipe. I tend to use water because it's cheap, but have made them with 3M engineered fluids, Fluorinert, and denatured alcohol. Fluorinert. I think that's what the expensive commercial CPU-cooling heatpipes use. $1000 a gallon! Or $5 a drum when you buy it at a salvage auction. That explains why low-end heatpipes use alcohol or acetone. Actually, one ought to be able to use the freon intended for automobile air conditioners, for a whole lot less money, even new. I've found that ordinary solder works just fine. A trick to make these things easy to build is to use a ball valve at the top (I'm assuming there is a top and we're going with gravity return because it's simple). I've got a few that are still under vacuum for several years now in this configuration. My giant heat pipe of doom is a 10 foot stick of 1/2 copper with a ball valve at one end and an end cap at the other. There is perhaps 100ml water in there total, and no air. You can either boil the liquid until it builds up a nice head of steam, or go the easy way and pull a vacuum with a pump and just close the valve. I wouldn't have thought that an ordinary ball valve would be tight enough, allowing the water to escape and the air enter, slowly, although I suppose one can replace the water if it comes to that. Mine have been running for a few years with no sign of needing to be pumped down again. They just work. But I think people want to build this exactly
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
I was wondering the same myself and found they are sold online at: http://secure.conwin.com/cgi-bin/store/cp-app.cgi?usr=51H4350135rnd=7294697rrc=Naffl=cip=92.132.242.176act=aff=pg=catref=navsynccatstr= - Original Message - From: Richard W. Solomon w1...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, December 28, 2009 4:49 PM Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference Does the factory sell direct in small quantities ? 73, Dick, W1KSZ -Original Message- From: Eamon Skelton nos...@oceanfree.net Sent: Dec 28, 2009 6:15 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference Giuseppe Marullo wrote: Hi all, just subscribed, I would like a quick advice on a 10MHz reference for calibrating my instruments and for fun. In particular, I would like to know if you could give me advice on EFRATOM FRS-A,FRS-C, DATUM LPRO-101, Thunderbolt and such. I would prefer a GPSDO (like the Thunderbolt), but budget is very tight (about 100EUR), so I am searching old surplus stuff on Ebay.snip A timing GPS receiver with a built-in 10MHz oscillator would fit your budget nicely. The Navsync CW12-TIM looks like the obvious choice. You would need the CW12-TIM module, a 3.3V DC supply and a suitable aerial/antenna. Power consumption is well below 1W. It has a 1PPS output with 30ns RMS accuracy and a NCO output with a default output frequency of 10MHz. http://www.navsync.com/docs/CW12-TIM_DS.pdf I paid just over Eur50 for mine last year when the Euro was very strong against foreign currencies. -- Linux 2.6.30 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Richard W. Solomon wrote: Does the factory sell direct in small quantities ? 73, Dick, W1KSZ I don't think so. I live in Cork, Ireland. Navsync are in Shannon about 70 miles from here. I ordered my CW12-TIM from Cutter Electronics in Australia. As they were out of stock at the time, I had to wait for a couple of weeks, while Navsync shipped them 20,000 miles from Ireland to Australia and back again :-) -- Linux 2.6.30 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Sal,
No it does not have a 10MHz output. However to calibrate an oscillator that is
very close to 10MHz you can use the 1PPS output to adjust it exactly. Trigger a
'scope with the 1PPS while monitoring the 10MHz, adjust the oscillator for
minimum drift across the screen.
Robert.
--- On Mon, 28/12/09, SAL CORNACCHIA salc...@rogers.com wrote:
From: SAL CORNACCHIA salc...@rogers.com
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Monday, 28 December, 2009, 15:32
Hi Robert,
Will the Motorola that You have mentioned give a 10.00 MHz output standard.
Thank You
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Robert Atkinson robert8...@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Cc: giuseppe.maru...@iname.com
Sent: Mon, December 28, 2009 5:14:49 AM
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Giuseppe,
Welcome to the group.
If you are already happy constructing equipment and have basic test gear
('scope, DMM) and a small budget, I'd suggest a timing GPS as a starting point.
While a Thunderbolt will give most of what you want, it is more expensive. A
Timing version or Motorola's Oncore (ebay item 300355981024 from flukel for
instance) will give you an accurate 1 pulse per second output (you also need a
power supply antenna and a PC). This and a 'scope will allow you to calibrate
other instruments and a oven controlled crystal oscillator. A GPS based
solution (including Thunderbolt) will give you good confidence of accuracy.
Just buying a surplus Rubidium could result in you adjusting all your
instruments to the wrong frequency! Like many of these decisions, it's a
balance between time and money, with a lesser input from your capabilities and
existing equipment.
Robert G8RPI.
--- On Mon, 28/12/09, Giuseppe Marullo giuse...@marullo.it wrote:
From: Giuseppe Marullo giuse...@marullo.it
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Monday, 28 December, 2009, 0:56
Thanks a lot to all for your quick answer.
Rubinium should be good for my needs, but buying it surplus makes me think I
could get something very used (and abused) and it does not have the self
correcting thing thunderbolt has.
GPSDO gives me also the time, maybe with a supercool LCD display.
A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also
needs a GPS antenna of some sort.
Do you know exactly the power requirement? On Ebay I read 15W then few mA on
each branch (board only). Something is not clear to me.
The dark side of the noon already embraced I have
Giuseppe
PS: I am experiencing mail problems for the first time in many years, please
anyone willing to contact me directly do cc copy also this other email address:
giuseppe.maru...@iname.com while my ISP gathers back all the bits they lost (2
days of emails vanished from my IMAP account under my eyes, literally)
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
snip Maybe a GPSDO myself, who knows...wondering if this could be done all digital, without using a DAC, without using a driving voltage for a OCXO. Giuseppe Symmetricom made a OXCO that had the DAC built-in so it was controlled by a digital interface. But it is hard to find, seen them on ebay but not now. Stanley ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Thank You Robert for the quick response.
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Robert Atkinson robert8...@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Mon, December 28, 2009 12:07:21 PM
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Sal,
No it does not have a 10MHz output. However to calibrate an oscillator that is
very close to 10MHz you can use the 1PPS output to adjust it exactly. Trigger a
'scope with the 1PPS while monitoring the 10MHz, adjust the oscillator for
minimum drift across the screen.
Robert.
--- On Mon, 28/12/09, SAL CORNACCHIA salc...@rogers.com wrote:
From: SAL CORNACCHIA salc...@rogers.com
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Monday, 28 December, 2009, 15:32
Hi Robert,
Will the Motorola that You have mentioned give a 10.00 MHz output standard.
Thank You
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Robert Atkinson robert8...@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Cc: giuseppe.maru...@iname.com
Sent: Mon, December 28, 2009 5:14:49 AM
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Giuseppe,
Welcome to the group.
If you are already happy constructing equipment and have basic test gear
('scope, DMM) and a small budget, I'd suggest a timing GPS as a starting point.
While a Thunderbolt will give most of what you want, it is more expensive. A
Timing version or Motorola's Oncore (ebay item 300355981024 from flukel for
instance) will give you an accurate 1 pulse per second output (you also need a
power supply antenna and a PC). This and a 'scope will allow you to calibrate
other instruments and a oven controlled crystal oscillator. A GPS based
solution (including Thunderbolt) will give you good confidence of accuracy.
Just buying a surplus Rubidium could result in you adjusting all your
instruments to the wrong frequency! Like many of these decisions, it's a
balance between time and money, with a lesser input from your capabilities and
existing equipment.
Robert G8RPI.
--- On Mon, 28/12/09, Giuseppe Marullo giuse...@marullo.it wrote:
From: Giuseppe Marullo giuse...@marullo.it
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Monday, 28 December, 2009, 0:56
Thanks a lot to all for your quick answer.
Rubinium should be good for my needs, but buying it surplus makes me think I
could get something very used (and abused) and it does not have the self
correcting thing thunderbolt has.
GPSDO gives me also the time, maybe with a supercool LCD display.
A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also
needs a GPS antenna of some sort.
Do you know exactly the power requirement? On Ebay I read 15W then few mA on
each branch (board only). Something is not clear to me.
The dark side of the noon already embraced I have
Giuseppe
PS: I am experiencing mail problems for the first time in many years, please
anyone willing to contact me directly do cc copy also this other email address:
giuseppe.maru...@iname.com while my ISP gathers back all the bits they lost (2
days of emails vanished from my IMAP account under my eyes, literally)
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Does the factory sell direct in small quantities ? From here (California), googling for Navsync CW12-TIM finds: http://www.semiconductorstore.com/pages/asp/supplier.asp?pl=0138gclid=CL_G5ar W-Z4CFU1M5Qod1XNWLA (Sorry for the line wrap.) -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Lady Heather screen-capture request...
Fellow Time-Nuts-- Mark Sims posted a screen capture of his Lady Heather screen display. In the interest of comparing my LH screen display to what others see, could I impose on some other list members to send me a screen capture of their LH screen display? Or-- if you are using the LH v3.0 beta, send me a screen capture of that as well? There are several anomalies I see from time to time that I am not sure if are normal or not and comparing to other LH users would be a big help!! Send screen captures (.gif is OK) to me at mpb45 (at) clanbaker (dot) org Thanks!! Mike Baker Micanopy, FL --- ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Cheap Rubidium (heatpipe cooling for)
Hi The short term stability *may* improve with temperature stabilization, even if the static temperature performance is fairly good. Since all of the rubidium guys sell parts with many different options. Trying to find out exactly what the rubidium you have in your hand does can be difficult. I suspect that testing the actual device may be the only sure way to do it. Bob On Dec 28, 2009, at 10:52 AM, ewkeh...@aol.com wrote: Hi With all the dialog on controlling temperature of the Rb unit I decided to take my Frequency Electronics Inc. 5062B apart since the Oven Controlled Oscillator and Rb Physics Package are separate and I may want to replace the oscillator with a HP 10811 that Corby has tested to be better than 1 E 12 from 1 to 100 sec. In order to proceed it would help if any one out there has any information on the circuitry, the unit has two modules and two PC boards. The boards are power supply and synthesizer and the modules are Rb unit and oscillator. I have opened the Rb unit and I am convinced that it can be a candidate for heat pipe cooling. Since it can be operated separate from the rest of the unit it will be possible to measure heat rise. The published plot of a 5600 shows a temp performance of +- 3 E -11 from -5 to +45 C. I am not sure if there is room for improvement. Any help would be greatly appreciated. Bert KehrenWB5MZJMiami In a message dated 12/27/2009 2:18:14 P.M. Eastern Standard Time, li...@cq.nu writes: Hi The tip it and listen to it slam test is a standard way of checking out a triple point of water cell for basically the same reason (you check the vacuum. Of course since a TWP cell is thin glass and not a nice metal pipe, you *may* break the seal by testing it Bob On Dec 27, 2009, at 9:33 AM, Joe Gwinn wrote: At 12:00 PM + 12/27/09, time-nuts-requ...@febo.com wrote: Date: Sat, 26 Dec 2009 17:04:46 -0700 From: Robert Darlington rdarling...@gmail.com Subject: Re: [time-nuts] Cheap Rubidium (heatpipe cooling for) To: Discussion of precise time and frequency measurement time-nuts@febo.com My comments are in-line, below On Fri, Dec 25, 2009 at 4:38 PM, Joe Gwinn joegw...@comcast.net wrote: At 12:45 AM + 12/25/09, time-nuts-requ...@febo.com wrote: Date: Thu, 24 Dec 2009 17:14:38 -0700 From: Robert Darlington rdarling...@gmail.com Subject: Re: [time-nuts] Cheap Rubidium (heatpipe cooling for) To: Discussion of precise time and frequency measurement time-nuts@febo.com On Thu, Dec 24, 2009 at 1:32 PM, Bob Camp li...@cq.nu wrote: Hi A heat pipe might work if the fluid had a sufficiently low boiling point. The working fluid in a heat pipe will boil at every temperature above its melting point. Well, I've been thinking about this, and I used the term heat pipe too loosely. Both the one- and two-pipe systems mentioned here have no wicks, and so technically are two-phase thermosyphons, which depend on gravity to circulate vapor and condensate. A true heat pipe has a wick, and will work in zero gravity. One gets significant heat transfer by phase change so long as the vapor pressure in the heat input end is high enough to generate enough vapor to carry the thermal power flow, and this makes the pipe isothermal. However the temperature (although constant along the pipe) varies with the thermal power flow (in thermal watts) being carried. What I'm looking for is related but different: A device where the heat transfer capacity varies sharply with temperature, so that there is a range of heat transfer rates over which the input-end temperature will be substantially constant. This is why I envision the fluid boiling (versus evaporating), which is actually out of the operating regime of a true heat pipe. I tend to use water because it's cheap, but have made them with 3M engineered fluids, Fluorinert, and denatured alcohol. Fluorinert. I think that's what the expensive commercial CPU-cooling heatpipes use. $1000 a gallon! Or $5 a drum when you buy it at a salvage auction. That explains why low-end heatpipes use alcohol or acetone. Actually, one ought to be able to use the freon intended for automobile air conditioners, for a whole lot less money, even new. I've found that ordinary solder works just fine. A trick to make these things easy to build is to use a ball valve at the top (I'm assuming there is a top and we're going with gravity return because it's simple). I've got a few that are still under vacuum for several years now in this configuration. My giant heat pipe of doom is a 10 foot stick of 1/2 copper with a ball valve at one end and an end cap at the other. There is perhaps 100ml water in there total, and no air. You can either boil the liquid until it builds up a nice
Re: [time-nuts] Thunderbolt oscillator temperature sensitivity
Hi The oscillator tempco shown on the screen is -1.6 ppb per degree C. 1/10 of that would be 0.16 ppb/C. I would hope that the oscillator in your Thunderbolt is much better than that. I suspect that the temperature cycling has the poor little gizmo a bit confused. Bob On Dec 28, 2009, at 11:20 AM, Mark Sims wrote: Ever wonder if a +/- .01C temperature cycle would have any measurable effect on the Thunderbolt oscillator? Well, wonder no more... Attached is a plot (in red) of the fast Fourier transform of the Tbolt oscillator data. The temperature was cycling +/- .01C with a period of 635.6 seconds. That big red spike in the FFT data (just under the ':' in the Filter: in the plot) is also at 635.6 seconds. Ignore the OSC tempco value shown since that measurement needs to be done with the oscillator undisciplined and the temperature moving... the true value is around 1/10th that. _ Hotmail: Free, trusted and rich email service. http://clk.atdmt.com/GBL/go/171222984/direct/01/oscfft.gif___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Cheap Rubidium (heatpipe cooling for)
Thanks Bert In a message dated 12/28/2009 12:48:20 P.M. Eastern Standard Time, li...@cq.nu writes: Hi The short term stability *may* improve with temperature stabilization, even if the static temperature performance is fairly good. Since all of the rubidium guys sell parts with many different options. Trying to find out exactly what the rubidium you have in your hand does can be difficult. I suspect that testing the actual device may be the only sure way to do it. Bob On Dec 28, 2009, at 10:52 AM, ewkeh...@aol.com wrote: Hi With all the dialog on controlling temperature of the Rb unit I decided to take my Frequency Electronics Inc. 5062B apart since the Oven Controlled Oscillator and Rb Physics Package are separate and I may want to replace the oscillator with a HP 10811 that Corby has tested to be better than 1 E 12 from 1 to 100 sec. In order to proceed it would help if any one out there has any information on the circuitry, the unit has two modules and two PC boards. The boards are power supply and synthesizer and the modules are Rb unit and oscillator. I have opened the Rb unit and I am convinced that it can be a candidate for heat pipe cooling. Since it can be operated separate from the rest of the unit it will be possible to measure heat rise. The published plot of a 5600 shows a temp performance of +- 3 E -11 from -5 to +45 C. I am not sure if there is room for improvement. Any help would be greatly appreciated. Bert KehrenWB5MZJMiami In a message dated 12/27/2009 2:18:14 P.M. Eastern Standard Time, li...@cq.nu writes: Hi The tip it and listen to it slam test is a standard way of checking out a triple point of water cell for basically the same reason (you check the vacuum. Of course since a TWP cell is thin glass and not a nice metal pipe, you *may* break the seal by testing it Bob On Dec 27, 2009, at 9:33 AM, Joe Gwinn wrote: At 12:00 PM + 12/27/09, time-nuts-requ...@febo.com wrote: Date: Sat, 26 Dec 2009 17:04:46 -0700 From: Robert Darlington rdarling...@gmail.com Subject: Re: [time-nuts] Cheap Rubidium (heatpipe cooling for) To: Discussion of precise time and frequency measurement time-nuts@febo.com My comments are in-line, below On Fri, Dec 25, 2009 at 4:38 PM, Joe Gwinn joegw...@comcast.net wrote: At 12:45 AM + 12/25/09, time-nuts-requ...@febo.com wrote: Date: Thu, 24 Dec 2009 17:14:38 -0700 From: Robert Darlington rdarling...@gmail.com Subject: Re: [time-nuts] Cheap Rubidium (heatpipe cooling for) To: Discussion of precise time and frequency measurement time-nuts@febo.com On Thu, Dec 24, 2009 at 1:32 PM, Bob Camp li...@cq.nu wrote: Hi A heat pipe might work if the fluid had a sufficiently low boiling point. The working fluid in a heat pipe will boil at every temperature above its melting point. Well, I've been thinking about this, and I used the term heat pipe too loosely. Both the one- and two-pipe systems mentioned here have no wicks, and so technically are two-phase thermosyphons, which depend on gravity to circulate vapor and condensate. A true heat pipe has a wick, and will work in zero gravity. One gets significant heat transfer by phase change so long as the vapor pressure in the heat input end is high enough to generate enough vapor to carry the thermal power flow, and this makes the pipe isothermal. However the temperature (although constant along the pipe) varies with the thermal power flow (in thermal watts) being carried. What I'm looking for is related but different: A device where the heat transfer capacity varies sharply with temperature, so that there is a range of heat transfer rates over which the input-end temperature will be substantially constant. This is why I envision the fluid boiling (versus evaporating), which is actually out of the operating regime of a true heat pipe. I tend to use water because it's cheap, but have made them with 3M engineered fluids, Fluorinert, and denatured alcohol. Fluorinert. I think that's what the expensive commercial CPU-cooling heatpipes use. $1000 a gallon! Or $5 a drum when you buy it at a salvage auction. That explains why low-end heatpipes use alcohol or acetone. Actually, one ought to be able to use the freon intended for automobile air conditioners, for a whole lot less money, even new. I've found that ordinary solder works just fine. A trick to make these things easy to build is to use a ball valve at the top (I'm assuming there is a top and we're going with gravity return because it's simple). I've got a few that are still under vacuum for several years now in this configuration. My giant heat pipe
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
One thing to keep in mind about the CW-12 is that the version they're selling now runs NMEA software only - which means no TRAIM functionality. If you do manage to find the Motorola version to get TRAIM, you lose the ability to change the oscillator frequency. It's fixed at 10 MHz. I bought my CW-12 a year or two ago from Semiconductorstore.com and they said it was the Motorola load. It wasn't. They did manage to get me a copy of the program to flash it to the Motorola load. That's when I realized I couldn't change the frequency. Oh, well. Ed - Original Message - From: Hal Murray hmur...@megapathdsl.net Date: Monday, December 28, 2009 11:44 am Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference Does the factory sell direct in small quantities ? From here (California), googling for Navsync CW12-TIM finds: http://www.semiconductorstore.com/pages/asp/supplier.asp?pl=0138gclid=CL_G5ar W-Z4CFU1M5Qod1XNWLA (Sorry for the line wrap.) -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi- bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 65, Issue 112
The HP 10811A (generally regarded as a pretty good oscillator) has a spec of 4.5E-9 over 70C which is 6.4E-11/C. If I'm reading my notes correctly, that tbolt oscillator measured at 1.4732E-10 parts/C... about 2.3 times worse than a 10811A. Generally Thunderbolt oscillators have rather crappy tempcos. There has been a lot of talk about them being double oven units, but I seriously doubt that. They make pretty good T to F converters... Note that some of the tempco could be due to the power supply, it is outside of the temperature controlled box. A previous test indicated that about 1/3 of the tempco was due to power supply variations) Those temperature cycles in the graph are +/- 10 millidegrees... the oscillator should be moving 3 parts/trillion over the cycle (assuming no thermal lag). Such a small change shows up very clearly in the self-reported OSC error data from the Thunderbolt. -- The oscillator tempco shown on the screen is -1.6 ppb per degree C. 1/10 of that would be 0.16 ppb/C. I would hope that the oscillator in your Thunderbolt is much better than that. _ Hotmail: Free, trusted and rich email service. http://clk.atdmt.com/GBL/go/171222984/direct/01/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 65, Issue 103
Tough to beat a self winding quartz wrist watch, unless it's not accurate enough to do what you need to do. I thought the self-winding watches were mechanical and that quartz watches ran off batteries. Did I miss something? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 65, Issue 103
Hi There is a sub-species of quartz watch that is indeed self winding. Seiko makes them in competition to Citizen's solar charging quartz watches. Bob On Dec 28, 2009, at 2:00 PM, Hal Murray wrote: Tough to beat a self winding quartz wrist watch, unless it's not accurate enough to do what you need to do. I thought the self-winding watches were mechanical and that quartz watches ran off batteries. Did I miss something? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Digest, Vol 65, Issue 112
Hi It's a pretty good bet that at 10 minutes the OCXO is still trying to stabilize from a temperature step. Do you know which oscillator your Tbolt has in it? There have been several different ones used over the years. Some are better than others ... Bob On Dec 28, 2009, at 1:45 PM, Mark Sims wrote: The HP 10811A (generally regarded as a pretty good oscillator) has a spec of 4.5E-9 over 70C which is 6.4E-11/C. If I'm reading my notes correctly, that tbolt oscillator measured at 1.4732E-10 parts/C... about 2.3 times worse than a 10811A. Generally Thunderbolt oscillators have rather crappy tempcos. There has been a lot of talk about them being double oven units, but I seriously doubt that. They make pretty good T to F converters... Note that some of the tempco could be due to the power supply, it is outside of the temperature controlled box. A previous test indicated that about 1/3 of the tempco was due to power supply variations) Those temperature cycles in the graph are +/- 10 millidegrees... the oscillator should be moving 3 parts/trillion over the cycle (assuming no thermal lag). Such a small change shows up very clearly in the self-reported OSC error data from the Thunderbolt. -- The oscillator tempco shown on the screen is -1.6 ppb per degree C. 1/10 of that would be 0.16 ppb/C. I would hope that the oscillator in your Thunderbolt is much better than that. _ Hotmail: Free, trusted and rich email service. http://clk.atdmt.com/GBL/go/171222984/direct/01/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Notes on the Driscoll VHF Overtone Crystal Oscillator
- Original Nachricht Von: Bruce Griffiths bruce.griffi...@xtra.co.nz An: Discussion of precise time and frequency measurement time-nuts@febo.com Datum: 28.12.2009 06:52 An inductor in series with the 220 ohm emitter resistor will improve the phase noise floor. In theory, yes. But already with only 220 Ohms, Q3 will oscillate wildly at a few hundred MHz. The mechanism is this: Somewhat hot RF transistor NE688, collector at RF ground, emitter at high-ish impedance --- When you measure into the base, you see a negative resistance in series with a few pF. Add L6 = 82 nH with the other side at RF ground and you have built the usual negative-impedance VCO for VHF/UHF. The crystal and the intended feedback network just don't matter any more. I should have re-read my own Dubus article on oscillator simulations from 6 years ago before I tried the Distaw. :-( Other people have observed the wild oscillations, too. The MMIC output amplifier has a wider bandwidth than necessary and doesn't have a particularly high reverse isolation. Also, it has 20 dB gain, that alone guarantees a less than ideal far-off noise level. The BAS70 clips at less than 1 V pp, this should be more. Could be easily done in the Rohde style with a decoupled DC divider and one Schottky that points from the divider to the collector circuit. I have changed my own locked VHF crystal oscillator back to Butler - this time single stage with 3* cheap NXP BF862 in parallel, common gate. The gate can be grounded directly, needs no voltage divider and decoupling. Input impedance of the 3 FETs is abt. 7 Ohms, which brings us close to the point of diminishing returns for the usual 45 Ohm crystal. The BF862 works to 700 MHz, so it is just fast enough and won't surprise me at 3 GHz. regards, Gerhard dk4xp ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt oscillator temperature sensitivity
Mark In part it depends on your TC and Damping settings as well as how sensitive your Osc is to temperature. And just as important is how well your temperature controller is really doing at holding the OXCO's temperature. From what I've seen, It is just as likely the Fourier spike AND the Temp cycle spike are BOTH caused by an outside source, such as your Heater cycling, maybe by way of the power supply etc. It does Not have to mean the 0.01 deg is causing the problem. If you can measure it, then it just means there is still room for improvement, and that your Temp control and Tbolt setup may not be perfect yet. ws * - Original Message - From: Mark Sims hol...@hotmail.com To: time-nuts@febo.com Sent: Monday, December 28, 2009 8:20 AM Subject: [time-nuts] Thunderbolt oscillator temperature sensitivity Ever wonder if a +/- .01C temperature cycle would have any measurable effect on the Thunderbolt oscillator? Well, wonder no more... Attached is a plot (in red) of the fast Fourier transform of the Tbolt oscillator data. The temperature was cycling +/- .01C with a period of 635.6 seconds. That big red spike in the FFT data (just under the ':' in the Filter: in the plot) is also at 635.6 seconds. Ignore the OSC tempco value shown since that measurement needs to be done with the oscillator undisciplined and the temperature moving... the true value is around 1/10th that. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Help identifying coax connector type
Thanks again to all for helping to identify these parts. If anybody is interested in some of them, drop me a line and I'll make you a deal! -Pete On Dec 7, 2009, at 12:38 AM, Peter Loron wrote: I have recently acquired a number of nice coax parts, but I'm not sure exactly what connector types they are. If anybody can help me identify them, I'd appreciate it! First, are these spiffy jacks. They look somewhat like SMB, but are too large as far as I know. Too small for BNC, and there's no bayonet. http://www.flickr.com/photos/24004...@n03/4165880386/ http://www.flickr.com/photos/24004...@n03/4165880282/ http://www.flickr.com/photos/24004...@n03/4165880166/ Next is this coax jumper cable. Unknown connectors on both ends: http://www.flickr.com/photos/24004...@n03/4165122135/ http://www.flickr.com/photos/24004...@n03/4165122541/ http://www.flickr.com/photos/24004...@n03/4165122411/ Last is another cable, with yet another unknown connector on it: http://www.flickr.com/photos/24004...@n03/4165881034/ Thanks! -Pete ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lady Heather screen-capture request...
Fellow Time-Nuts-- Mark Sims posted a screen capture of his Lady Heather screen display. In the interest of comparing my LH screen display to what others see, could I impose on some other list members to send me a screen capture of their LH screen display? Or-- if you are using the LH v3.0 beta, send me a screen capture of that as well? There are several anomalies I see from time to time that I am not sure if are normal or not and comparing to other LH users would be a big help!! Send screen captures (.gif is OK) to me at mpb45 (at) clanbaker (dot) org Individual screenshots may not be very useful without specifying the timescale, filters, and graphs you're looking for. Note that you can still run the 3.0 beta with /ip=ke5fx.dyndns.org:45000, which is a secondary Thunderbolt in my house that is still online for testing purposes. It's a good performer as long as nobody else is also logging in and entering weird parameter values. :) -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Self winding quartz watches
li...@cq.nu said: There is a sub-species of quartz watch that is indeed self winding. Seiko makes them in competition to Citizen's solar charging quartz watches. Thanks. Now that I know what to look for... http://en.wikipedia.org/wiki/Automatic_quartz -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Giuseppe Marullo wrote: Robert, Welcome to the group. Thank you and all the others, you are giving me a lot of informations. BTW, my provider retrieved my emails so I am fully operational (at least I hope). while I did not originally envision building this kind of equipment, I could do it while it lies well within the digital domain, I have some test gear (frequency counter, DMM, analog scope, BF frequency generator, LA and some FPGAs with 100+Msamples ADC) but...I will have to trust it so I am back at square one, until I have a reliable source... I would like a GPSDO, possibly ready to run, then I will start building something that I could actually check against the GPSDO. Maybe a GPSDO myself, who knows...wondering if this could be done all digital, without using a DAC, without using a driving voltage for a OCXO. Giuseppe Giuseppe One can use a DDS or equivalent phase continuous high resolution sysnthesizer to produce a corrected output frequency using the OCXO frequency as an input, however the DDS itself uses a DAC and you will probably need to use a few cascaded mix and divide stages to reduce the spur amplitude to an acceptable level. This has the advantage that one can use an OCXO that either doesnt have an EFC input or one that has drifted beyond the adjustment range (via EFC and/or mechanical trimmer) but is otherwise quiet and stable. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Notes on the Driscoll VHF Overtone Crystal Oscillator
dk...@arcor.de wrote: - Original Nachricht Von: Bruce Griffithsbruce.griffi...@xtra.co.nz An: Discussion of precise time and frequency measurementtime-nuts@febo.com Datum: 28.12.2009 06:52 An inductor in series with the 220 ohm emitter resistor will improve the phase noise floor. In theory, yes. But already with only 220 Ohms, Q3 will oscillate wildly at a few hundred MHz. The mechanism is this: Somewhat hot RF transistor NE688, collector at RF ground, emitter at high-ish impedance --- When you measure into the base, you see a negative resistance in series with a few pF. Using a transistor with a higher ft than necessary in an oscillator circuit isnt usually a good idea. Add L6 = 82 nH with the other side at RF ground and you have built the usual negative-impedance VCO for VHF/UHF. The crystal and the intended feedback network just don't matter any more. I should have re-read my own Dubus article on oscillator simulations from 6 years ago before I tried the Distaw. :-( Other people have observed the wild oscillations, too. Even without significant inductance between the oscillator transistor base and ground the shunt capacitance of the crystal itself can cause parasitic oscillations to occur. A high frequencies the base is grounded via the tank capacitor, and the emitter impedance exhibits a negative resistance in series with an inductance. Driscoll actually used ferrite beads on base and collector leads to suppress such oscillations. The location of these beads is clearly shown in the original paper. Driscoll used a capacitively split tank so that there is a capacitor from the oscillator transistor base to ground. The MMIC output amplifier has a wider bandwidth than necessary and doesn't have a particularly high reverse isolation. Also, it has 20 dB gain, that alone guarantees a less than ideal far-off noise level. The BAS70 clips at less than 1 V pp, this should be more. Could be easily done in the Rohde style with a decoupled DC divider and one Schottky that points from the divider to the collector circuit. A symmetric clipper (easily implemented by dc biasing an AC coupled 2 diode pp detector) has some advantages. I have changed my own locked VHF crystal oscillator back to Butler - this time single stage with 3* cheap NXP BF862 in parallel, common gate. The gate can be grounded directly, needs no voltage divider and decoupling. Input impedance of the 3 FETs is abt. 7 Ohms, which brings us close to the point of diminishing returns for the usual 45 Ohm crystal. The BF862 works to 700 MHz, so it is just fast enough and won't surprise me at 3 GHz. regards, Gerhard dk4xp Some of Driscoll's later low phase noise OCXOs employ an MMIC as the oscillator and use the crystal together with a diode limiter and matching circuits to match the crystal to the 50 ohm input and output impedance of the MMIC. A splitter at the MMIC output is used. One splitter output drives the feedback loop whilst the other is used to drive the ooutput buffer. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Can a quartz crystal go off by 2% ?
I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me money, as I pay a higher price per unit during the expensive period, to compensate for the fact I get it cheap for 7 hours. But I run some computers 24/7. I guess I should do the maths and work it out. Apart from some heaters in the garage, which are very rarely used, I no longer heat with it. The time when the electric is cheap is set by a clock, which rotates once/day. It says on it quartz somewhere, so it must be regulated by a crystal and not from the 50 Hz supply, which would be pretty useless, as the clock would go wrong if there was ever a power failure. The clock has not been changed in the 17 years I've lived at my house, though the meter has on a couple of occasions. The clock used to keep accurate, but now it looses time about 30 minutes/day. I wrote a computer program to predict when the electric is cheap, so we can schedule when things like the washing machine, dishwasher, Hoover etc are used. Even cooking to a certain extent, if it's convenient, though our life does not revolve around the cheap electric. I'm wondering if this is a mechanical fault in the clock, or whether the crystal has developed a fault. It's clearly well outside any tolerance or aging process of any crystal - even the cheapest ones. I've not done any very extensive tests, but the error does not appear to be constant. Hence every month or so I need to produce a new table, as my predictions get less accurate with time. Since one can only read the clock to an accuracy of about 15 minutes, it's not easy to know how far it is out. Sometimes we hear the contactor go over, as this is supposed to then power the storage heaters, which we no long use. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
It is possible the crystal has succumbed to a mechanical fatigue. To check I used an old relay coil with a ferrite rod stuffed through it and tuned to 32.6khz. If you have a sensitive enough counter you may be able to measure this without an amp in line. (2% is a long way out !) It could also be the trimmer capacitor that has failed. I doubt there is much more mechanical, other than a dodgy solder joint. In all probability it will be the bane of all lovers of old electronicsthe power supply electrolytic capacitors..remember battery quartz clocks run slow or fast as the batt runs out. Alan G3NYK --- On Mon, 28/12/09, Dr. David Kirkby david.kir...@onetel.net wrote: From: Dr. David Kirkby david.kir...@onetel.net Subject: [time-nuts] Can a quartz crystal go off by 2% ? To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, 28 December, 2009, 23:22 I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me money, as I pay a higher price per unit during the expensive period, to compensate for the fact I get it cheap for 7 hours. But I run some computers 24/7. I guess I should do the maths and work it out. Apart from some heaters in the garage, which are very rarely used, I no longer heat with it. The time when the electric is cheap is set by a clock, which rotates once/day. It says on it quartz somewhere, so it must be regulated by a crystal and not from the 50 Hz supply, which would be pretty useless, as the clock would go wrong if there was ever a power failure. The clock has not been changed in the 17 years I've lived at my house, though the meter has on a couple of occasions. The clock used to keep accurate, but now it looses time about 30 minutes/day. I wrote a computer program to predict when the electric is cheap, so we can schedule when things like the washing machine, dishwasher, Hoover etc are used. Even cooking to a certain extent, if it's convenient, though our life does not revolve around the cheap electric. I'm wondering if this is a mechanical fault in the clock, or whether the crystal has developed a fault. It's clearly well outside any tolerance or aging process of any crystal - even the cheapest ones. I've not done any very extensive tests, but the error does not appear to be constant. Hence every month or so I need to produce a new table, as my predictions get less accurate with time. Since one can only read the clock to an accuracy of about 15 minutes, it's not easy to know how far it is out. Sometimes we hear the contactor go over, as this is supposed to then power the storage heaters, which we no long use. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Notes on the Driscoll VHF Overtone Crystal (time-nuts Digest, Vol 65, Issue 114)
Von: Magnus Lindahl sm4...@telia.com Do you have schematics, PCB-design etc. to share on your design with 3* BF862? I will publish the results in Dubus. (www.dubus.org) board size is 1.5 * 2.5 inch for oscillator, buffer, reference conditioner and PLL. No soldering without a microscope, however. Lots of SSOP16, sot-336, 0603 friends. I wanted to make a VHF crystal oscillator that could be locked to a 10 MHz reference and be used for the usual transverter designs. That required a locking grid of 333 or 500 KHz. Furthermore, I wanted to avoid microcontrollers and other stuff that had to be programmed. I wanted just normal stuff from Digi-Key and your favorite crystal supplier. (Also, I wanted a nice clock source for state-of-the-Art 16 bit ADCs) The fine locking grid has a devastating influence on the design. Either one compares at 500 KHz, then locking to small error will take months, the pull-in range is ridiculous (I don't want an oven for the 100MHz) or one compares to a harmonic of the 500 KHz, then the phase comparator gain is ridiculous and the PLL kills the 100 MHz phase noise. Probably I'll give in and stay with a 10 MHz grid. That will help hams who want to multiply to 100 GHz and above. I now have limited access to an Agilent signal source analyzer that does the three cornered hat thing with cross correlation to 2 precision oscillators close to real time. I'm still stuck at -135 dB@ 100Hz @100 MHz, but without Rohde's limiter. (only antiparallel Schottky across tank circuit and with BFG196 emitter follower) I'll test w/o the follower and with the new limiter in week 1/2010 There are many things still to explore: thin film vs thick film resistors, influence of emitter/source resistors, amplitude clamps, crystals, ... regards, Gerhard DK4XP U.L.Rohde/David P. Newkirk: RF/Microwave Circuit Design For Wireless Applications, page 762++ Wiley, ISBN 0-471-29818-2 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
ALAN MELIA wrote: It is possible the crystal has succumbed to a mechanical fatigue. To check I used an old relay coil with a ferrite rod stuffed through it and tuned to 32.6khz. If you have a sensitive enough counter you may be able to measure this without an amp in line. (2% is a long way out !) It could also be the trimmer capacitor that has failed. I doubt there is much more mechanical, other than a dodgy solder joint. In all probability it will be the bane of all lovers of old electronicsthe power supply electrolytic capacitors..remember battery quartz clocks run slow or fast as the batt runs out. Alan G3NYK It could be the battery is low. There clearly is a battery backup, and there is something on the clock which implies the holdover period is about 4 days. (I forget the exact wording). Clearly if there is a power failure, the clock must still rotate to keep accurate. I assume the battery is constantly charged by the incoming supply. Given the age of the battery ( 17 years), it is unlikely to be in good condition! But it should be charged all the time. But perhaps even when charged, its voltage is very different to what it should be. I would not have thought a trimmer cap going open-circuit could have induced a 2% change. That seems an awful lot. Thanks for the idea of the ferrite rod. Dave --- On Mon, 28/12/09, Dr. David Kirkby david.kir...@onetel.net wrote: From: Dr. David Kirkby david.kir...@onetel.net Subject: [time-nuts] Can a quartz crystal go off by 2% ? To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, 28 December, 2009, 23:22 I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me money, as I pay a higher price per unit during the expensive period, to compensate for the fact I get it cheap for 7 hours. But I run some computers 24/7. I guess I should do the maths and work it out. Apart from some heaters in the garage, which are very rarely used, I no longer heat with it. The time when the electric is cheap is set by a clock, which rotates once/day. It says on it quartz somewhere, so it must be regulated by a crystal and not from the 50 Hz supply, which would be pretty useless, as the clock would go wrong if there was ever a power failure. The clock has not been changed in the 17 years I've lived at my house, though the meter has on a couple of occasions. The clock used to keep accurate, but now it looses time about 30 minutes/day. I wrote a computer program to predict when the electric is cheap, so we can schedule when things like the washing machine, dishwasher, Hoover etc are used. Even cooking to a certain extent, if it's convenient, though our life does not revolve around the cheap electric. I'm wondering if this is a mechanical fault in the clock, or whether the crystal has developed a fault. It's clearly well outside any tolerance or aging process of any crystal - even the cheapest ones. I've not done any very extensive tests, but the error does not appear to be constant. Hence every month or so I need to produce a new table, as my predictions get less accurate with time. Since one can only read the clock to an accuracy of about 15 minutes, it's not easy to know how far it is out. Sometimes we hear the contactor go over, as this is supposed to then power the storage heaters, which we no long use. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
Dr. David Kirkby wrote: ALAN MELIA wrote: It is possible the crystal has succumbed to a mechanical fatigue. To check I used an old relay coil with a ferrite rod stuffed through it and tuned to 32.6khz. If you have a sensitive enough counter you may be able to measure this without an amp in line. (2% is a long way out !) It could also be the trimmer capacitor that has failed. I doubt there is much more mechanical, other than a dodgy solder joint. In all probability it will be the bane of all lovers of old electronicsthe power supply electrolytic capacitors..remember battery quartz clocks run slow or fast as the batt runs out. Alan G3NYK It could be the battery is low. There clearly is a battery backup, and there is something on the clock which implies the holdover period is about 4 days. (I forget the exact wording). Clearly if there is a power failure, the clock must still rotate to keep accurate. I assume the battery is constantly charged by the incoming supply. Given the age of the battery ( 17 years), it is unlikely to be in good condition! But it should be charged all the time. But perhaps even when charged, its voltage is very different to what it should be. I would not have thought a trimmer cap going open-circuit could have induced a 2% change. That seems an awful lot. If the trimmer in in series with the crystal and not shunted by another capacitor then the crystal will no longer control the oscillator frequency. 0.1pF or 0.01pF in series with a tuning fork crystal instead of the nominal value (20pf?) will make a singnificant difference. Thanks for the idea of the ferrite rod. Dave Bruce --- On Mon, 28/12/09, Dr. David Kirkby david.kir...@onetel.net wrote: From: Dr. David Kirkby david.kir...@onetel.net Subject: [time-nuts] Can a quartz crystal go off by 2% ? To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, 28 December, 2009, 23:22 I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me money, as I pay a higher price per unit during the expensive period, to compensate for the fact I get it cheap for 7 hours. But I run some computers 24/7. I guess I should do the maths and work it out. Apart from some heaters in the garage, which are very rarely used, I no longer heat with it. The time when the electric is cheap is set by a clock, which rotates once/day. It says on it quartz somewhere, so it must be regulated by a crystal and not from the 50 Hz supply, which would be pretty useless, as the clock would go wrong if there was ever a power failure. The clock has not been changed in the 17 years I've lived at my house, though the meter has on a couple of occasions. The clock used to keep accurate, but now it looses time about 30 minutes/day. I wrote a computer program to predict when the electric is cheap, so we can schedule when things like the washing machine, dishwasher, Hoover etc are used. Even cooking to a certain extent, if it's convenient, though our life does not revolve around the cheap electric. I'm wondering if this is a mechanical fault in the clock, or whether the crystal has developed a fault. It's clearly well outside any tolerance or aging process of any crystal - even the cheapest ones. I've not done any very extensive tests, but the error does not appear to be constant. Hence every month or so I need to produce a new table, as my predictions get less accurate with time. Since one can only read the clock to an accuracy of about 15 minutes, it's not easy to know how far it is out. Sometimes we hear the contactor go over, as this is supposed to then power the storage heaters, which we no long use. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
Bruce Griffiths wrote: If the trimmer in in series with the crystal and not shunted by another capacitor then the crystal will no longer control the oscillator frequency. 0.1pF or 0.01pF in series with a tuning fork crystal instead of the nominal value (20pf?) will make a singnificant difference. Thanks for the idea of the ferrite rod. Bruce Thank you. I guess thats a possible failure mechanism, though if there is no control, I'd doubt it would keep 98 % accurate. I would have expected it to stop. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
Hi Even with a tuning fork crystal, anything past about 0.2% is a very large changel. That's true for tuning and also true for normal aging. I suspect that something mechanical has happened. 1) A cracked crystal - unlikely 2).An electro magnet in the driving circuit no longer firing fully. a) Due to a bad magnet b) Due to low power c) Due to a dying chip 3) A worn escarpment. Time to get it replaced Bob On Dec 28, 2009, at 6:22 PM, Dr. David Kirkby wrote: I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me money, as I pay a higher price per unit during the expensive period, to compensate for the fact I get it cheap for 7 hours. But I run some computers 24/7. I guess I should do the maths and work it out. Apart from some heaters in the garage, which are very rarely used, I no longer heat with it. The time when the electric is cheap is set by a clock, which rotates once/day. It says on it quartz somewhere, so it must be regulated by a crystal and not from the 50 Hz supply, which would be pretty useless, as the clock would go wrong if there was ever a power failure. The clock has not been changed in the 17 years I've lived at my house, though the meter has on a couple of occasions. The clock used to keep accurate, but now it looses time about 30 minutes/day. I wrote a computer program to predict when the electric is cheap, so we can schedule when things like the washing machine, dishwasher, Hoover etc are used. Even cooking to a certain extent, if it's convenient, though our life does not revolve around the cheap electric. I'm wondering if this is a mechanical fault in the clock, or whether the crystal has developed a fault. It's clearly well outside any tolerance or aging process of any crystal - even the cheapest ones. I've not done any very extensive tests, but the error does not appear to be constant. Hence every month or so I need to produce a new table, as my predictions get less accurate with time. Since one can only read the clock to an accuracy of about 15 minutes, it's not easy to know how far it is out. Sometimes we hear the contactor go over, as this is supposed to then power the storage heaters, which we no long use. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
Hi David at 17 years the probably NiCd batts may have one at zero volts and the charge is constant curent so the clock supply will not be held up by the charger. My timer used alkalines and I replaced every 5 years. Alan G3NYK --- On Mon, 28/12/09, Dr. David Kirkby david.kir...@onetel.net wrote: From: Dr. David Kirkby david.kir...@onetel.net Subject: Re: [time-nuts] Can a quartz crystal go off by 2% ? To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, 28 December, 2009, 23:58 ALAN MELIA wrote: It is possible the crystal has succumbed to a mechanical fatigue. To check I used an old relay coil with a ferrite rod stuffed through it and tuned to 32.6khz. If you have a sensitive enough counter you may be able to measure this without an amp in line. (2% is a long way out !) It could also be the trimmer capacitor that has failed. I doubt there is much more mechanical, other than a dodgy solder joint. In all probability it will be the bane of all lovers of old electronicsthe power supply electrolytic capacitors..remember battery quartz clocks run slow or fast as the batt runs out. Alan G3NYK It could be the battery is low. There clearly is a battery backup, and there is something on the clock which implies the holdover period is about 4 days. (I forget the exact wording). Clearly if there is a power failure, the clock must still rotate to keep accurate. I assume the battery is constantly charged by the incoming supply. Given the age of the battery ( 17 years), it is unlikely to be in good condition! But it should be charged all the time. But perhaps even when charged, its voltage is very different to what it should be. I would not have thought a trimmer cap going open-circuit could have induced a 2% change. That seems an awful lot. Thanks for the idea of the ferrite rod. Dave --- On Mon, 28/12/09, Dr. David Kirkby david.kir...@onetel.net wrote: From: Dr. David Kirkby david.kir...@onetel.net Subject: [time-nuts] Can a quartz crystal go off by 2% ? To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, 28 December, 2009, 23:22 I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me money, as I pay a higher price per unit during the expensive period, to compensate for the fact I get it cheap for 7 hours. But I run some computers 24/7. I guess I should do the maths and work it out. Apart from some heaters in the garage, which are very rarely used, I no longer heat with it. The time when the electric is cheap is set by a clock, which rotates once/day. It says on it quartz somewhere, so it must be regulated by a crystal and not from the 50 Hz supply, which would be pretty useless, as the clock would go wrong if there was ever a power failure. The clock has not been changed in the 17 years I've lived at my house, though the meter has on a couple of occasions. The clock used to keep accurate, but now it looses time about 30 minutes/day. I wrote a computer program to predict when the electric is cheap, so we can schedule when things like the washing machine, dishwasher, Hoover etc are used. Even cooking to a certain extent, if it's convenient, though our life does not revolve around the cheap electric. I'm wondering if this is a mechanical fault in the clock, or whether the crystal has developed a fault. It's clearly well outside any tolerance or aging process of any crystal - even the cheapest ones. I've not done any very extensive tests, but the error does not appear to be constant. Hence every month or so I need to produce a new table, as my predictions get less accurate with time. Since one can only read the clock to an accuracy of about 15 minutes, it's not easy to know how far it is out. Sometimes we hear the contactor go over, as this is supposed to then power the storage heaters, which we no long use. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
Bob Camp wrote: Hi Even with a tuning fork crystal, anything past about 0.2% is a very large changel. That's true for tuning and also true for normal aging. I suspect that something mechanical has happened. 1) A cracked crystal - unlikely 2).An electro magnet in the driving circuit no longer firing fully. a) Due to a bad magnet b) Due to low power c) Due to a dying chip 3) A worn escarpment. Thank you Bob. Time to get it replaced No, I'm quite happy to get cheap electric during the day some times! It's more useful than having it in the middle of the night. So I'm not concerned over this, but just interested what might be the problem with it. Bob Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can a quartz crystal go off by 2% ?
ALAN MELIA wrote: Hi David at 17 years the probably NiCd batts may have one at zero volts and the charge is constant curent so the clock supply will not be held up by the charger. My timer used alkalines and I replaced every 5 years. Alan G3NYK A recent power failure did not cause the clock to stop, so some battery power must exist, but I believe the clock may have run a bit slower during that period, as there was a bit of a kink in the graph, but due to the limited amount of data, its hard to be precise about this. But I believe the power failure did throw my estimates off a bit more than usual. Dave --- On Mon, 28/12/09, Dr. David Kirkby david.kir...@onetel.net wrote: From: Dr. David Kirkby david.kir...@onetel.net Subject: Re: [time-nuts] Can a quartz crystal go off by 2% ? To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, 28 December, 2009, 23:58 ALAN MELIA wrote: It is possible the crystal has succumbed to a mechanical fatigue. To check I used an old relay coil with a ferrite rod stuffed through it and tuned to 32.6khz. If you have a sensitive enough counter you may be able to measure this without an amp in line. (2% is a long way out !) It could also be the trimmer capacitor that has failed. I doubt there is much more mechanical, other than a dodgy solder joint. In all probability it will be the bane of all lovers of old electronicsthe power supply electrolytic capacitors..remember battery quartz clocks run slow or fast as the batt runs out. Alan G3NYK It could be the battery is low. There clearly is a battery backup, and there is something on the clock which implies the holdover period is about 4 days. (I forget the exact wording). Clearly if there is a power failure, the clock must still rotate to keep accurate. I assume the battery is constantly charged by the incoming supply. Given the age of the battery ( 17 years), it is unlikely to be in good condition! But it should be charged all the time. But perhaps even when charged, its voltage is very different to what it should be. I would not have thought a trimmer cap going open-circuit could have induced a 2% change. That seems an awful lot. Thanks for the idea of the ferrite rod. Dave --- On Mon, 28/12/09, Dr. David Kirkby david.kir...@onetel.net wrote: From: Dr. David Kirkby david.kir...@onetel.net Subject: [time-nuts] Can a quartz crystal go off by 2% ? To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Monday, 28 December, 2009, 23:22 I'm on the so-called 'Economy 7' electric in the UK, where I'm supposed to get cheap electric from 0030 to 0730 - i.e. a 7 hour period when electricity demand is low. I'm no longer heating by electric, but do run some computers 24/7. It's not totally clear whether this saves me money or costs me money, as I pay a higher price per unit during the expensive period, to compensate for the fact I get it cheap for 7 hours. But I run some computers 24/7. I guess I should do the maths and work it out. Apart from some heaters in the garage, which are very rarely used, I no longer heat with it. The time when the electric is cheap is set by a clock, which rotates once/day. It says on it quartz somewhere, so it must be regulated by a crystal and not from the 50 Hz supply, which would be pretty useless, as the clock would go wrong if there was ever a power failure. The clock has not been changed in the 17 years I've lived at my house, though the meter has on a couple of occasions. The clock used to keep accurate, but now it looses time about 30 minutes/day. I wrote a computer program to predict when the electric is cheap, so we can schedule when things like the washing machine, dishwasher, Hoover etc are used. Even cooking to a certain extent, if it's convenient, though our life does not revolve around the cheap electric. I'm wondering if this is a mechanical fault in the clock, or whether the crystal has developed a fault. It's clearly well outside any tolerance or aging process of any crystal - even the cheapest ones. I've not done any very extensive tests, but the error does not appear to be constant. Hence every month or so I need to produce a new table, as my predictions get less accurate with time. Since one can only read the clock to an accuracy of about 15 minutes, it's not easy to know how far it is out. Sometimes we hear the contactor go over, as this is supposed to then power the storage heaters, which we no long use. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions
[time-nuts] Sending me Lady Heather screen-captures....
Hello, Time-Nuts-- Many thanks to Warren S for sending me over 20 Lady Heather screen-captures showing different configurations!! I really appreciate seeing these and welcome anyone else on the list sending me their screen captures. John Miles commented that individual screenshots may not be very useful without specifying the timescale, filters, and graphs you're looking for. This is true, but I am not even sure what I am looking for,--and some of the filter configurations mean nothing to me!! At this stage, I am like the little boy on the sidewalk looking into the toy store window and saying, WOW!! How COOL!! Look at that, and that, and that!! Now I have some studying to do of the graphs of all the different filters and configurations-- this will take me a while as I am not really sure what I am looking at with some of the graphs. Thanks again Warren!! My Thunderbolt sits next to my desktop computer in the shop and I have made no attempt to thermally isolate it from ambient temperature excursions due to routine air-conditioner cycles in the summer and heat-pump cycles in the winter so I expect to see some regular variation of the temperature graph. I mainly use it's outputs to reference and lock my spectrum analyzer and frequency counters with. One mystery is that once or twice daily, the temperature graph exhibits a sharp, almost perfectly vertical spike which recovers over a period of a few minutes. The temperature cannot possibly change that rapidly so there is something else going on. LH often indicates that the blue PPS ADEV and the red OSC ADEV are both in the high E-13 zone for several hours and then invariably, both will drop back to the mid E-12 zone and sometimes stay there for many hours. Periodically, the violet PPS graph and the green DAC graph will go off scale for 10-15 minutes and I cannot find a reason for this-- it does not seem to be either temperature related or have anything to do with how strong the signals from the birds are or where the birds are relative to any tall tree foliage blocking the antenna sky view. Mike Baker --- ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sending me Lady Heather screen-captures....
One mystery is that once or twice daily, the temperature graph exhibits a sharp, almost perfectly vertical spike which recovers over a period of a few minutes. The temperature cannot possibly change that rapidly so there is something else going on. Note that the existing (non-beta) version of LH has some pretty debatable serial-port code in it. You may just be seeing data corruption. If it happens with the 3.0 beta version, it's may be worth investigating. LH often indicates that the blue PPS ADEV and the red OSC ADEV are both in the high E-13 zone for several hours and then invariably, both will drop back to the mid E-12 zone and sometimes stay there for many hours. Nature of the beast, really. A single outlier can affect your whole ADEV plot. Periodically, the violet PPS graph and the green DAC graph will go off scale for 10-15 minutes and I cannot find a reason for this-- it does not seem to be either temperature related or have anything to do with how strong the signals from the birds are or where the birds are relative to any tall tree foliage blocking the antenna sky view. The auto-scaling has undergone some improvements, too... if you're not running the beta, give that a try. -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Sending me Lady Heather screen-captures....
Those spikes/decays in the temperature plot are due to false readings the Tbolt firmware gets from the temperature sensor chip. They are an artifact of how the temperature sensor works in its high resolution mode. They are actually single sample spikes of 1C (I think) in the output of the sensor chip. The reported amplitude/decay is due to the filtering the Tbolt firmware does on the temperature readings. Also, remember that the ADEV values calculated by Lady Heather are from its internal measurements of the oscillator and PPS signal against the rather-noisy-in-the-short-term GPS signal. They tend to depart from the true ADEV values measured against a real external reference particularly at shorter values of tau (like 100 secs). Turn on the satellite count display (G C from the keyboard in ver 3.0). The Tbolt reacts rather poorly to changes in the group of satellites that it is tracking. When the tracked satellite constellation changes, you can get big jumps in the osc/pps/dac signals. To minimize constellation changes, set the signal level mask to a low value (like AMU=1.0) and the satellite elevation mask to a high value (like 25 degrees). _ Hotmail: Trusted email with powerful SPAM protection. http://clk.atdmt.com/GBL/go/177141665/direct/01/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
