Re: [time-nuts] What sort of oscillator is this?
On 9/28/14, 7:55 AM, Richard Karlquist wrote: I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. But I think HP did this sort of thing a lot. Something that would have cost very little to add, became an expensive option. In some cases these expensive options are nothing more than enabling a bit of software, although the RD cost of the software is probably a lot more than the hardware cost of adding a better oscillator. There's also a difference between the kind of oscillator in the instrument.. Rick can probably tell us for sure, but I've heard it rumored that counters typically got an oscillator optimized for accuracy and low aging, but not necessarily so hot for phase noise, while synthesizers and spectrum analyzers would get a good phase noise oscillator, but maybe with more aging, figuring that the cal lab at the customer's facility would reset the frequency every year anyway. I'm sure there's also some aspects of whether customers were more likely to have a house standard or leave the equipment powered on vs connected to power (so that a standby mode could keep the oscillator powered on). And that in turn was somewhat determined by whether the equipment was portable (has a handle, like a 8563 spectrum analyzer) or rack/bench (like a 8663 signal generator). The portable units aren't going to be powered on all the time, so you want something that is ready to go within a short time after plugging it in. I worked for the HP Santa Clara Division for 19 years. The reason why a customer would NOT want a precision oscillator in a high end instrument would be that he was going to use a house standard. We of course made OCXO's at SCD and sold them to other HP divisions. It would not be impossible for a division to use a TCXO, but it would be out of character given that we transferred 10811's at cost, which was then about $400. ___ 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] What sort of oscillator is this?
Hi On Dec 14, 2014, at 4:14 PM, Jim Lux jim...@earthlink.net wrote: On 9/28/14, 7:55 AM, Richard Karlquist wrote: I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. A *lot* of places that had this stuff ran it out of a frequency standard distribution system 100% of the time. If you saw “TCXO” in the specs, the first thing to do was call the HP sales guy and ask if you could get a discount on one that had a crystal instead….. But I think HP did this sort of thing a lot. Something that would have cost very little to add, became an expensive option. In some cases these expensive options are nothing more than enabling a bit of software, although the RD cost of the software is probably a lot more than the hardware cost of adding a better oscillator. There's also a difference between the kind of oscillator in the instrument.. Rick can probably tell us for sure, but I've heard it rumored that counters typically got an oscillator optimized for accuracy and low aging, but not necessarily so hot for phase noise, while synthesizers and spectrum analyzers would get a good phase noise oscillator, but maybe with more aging, figuring that the cal lab at the customer's facility would reset the frequency every year anyway. HP bought a *lot* of oscillators on the open market from a wide range of suppliers. They very much customized the spec’s on these oscillators to match what they felt were the needs of the target market for this or that piece of gear. I'm sure there's also some aspects of whether customers were more likely to have a house standard or leave the equipment powered on vs connected to power (so that a standby mode could keep the oscillator powered on). Back in the 80’s the federal government / DOD in the US issues an edict that gear could not be on overnight . Oddly enough they were a pretty large customer for this sort of gear. That did indeed impact the specs on the oscillators. In some cases the practice flowed down to contractor sites. That just increased the size of the market with on/off cycles. And that in turn was somewhat determined by whether the equipment was portable (has a handle, like a 8563 spectrum analyzer) or rack/bench (like a 8663 signal generator). The portable units aren't going to be powered on all the time, so you want something that is ready to go within a short time after plugging it in. Some of that gear got low powered OCXO’s Back in the days when manuals with schematics were common it was pretty easy to spot this sort of thing. Bob I worked for the HP Santa Clara Division for 19 years. The reason why a customer would NOT want a precision oscillator in a high end instrument would be that he was going to use a house standard. We of course made OCXO's at SCD and sold them to other HP divisions. It would not be impossible for a division to use a TCXO, but it would be out of character given that we transferred 10811's at cost, which was then about $400. ___ 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] What sort of oscillator is this?
David, Just a thought but have you tried Pasternack? They do 'custom' precision cabling including 2.4mm connector options. regards, Paul, G8GJA -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David Kirkby (Kirkby Microwave Ltd) Sent: 30 September 2014 00:16 To: Discussion of precise time and frequency measurement Cc: hmur...@megapathdsl.net Subject: Re: [time-nuts] What sort of oscillator is this? On 29 Sep 2014 20:06, Hal Murray hmur...@megapathdsl.net wrote: drkir...@kirkbymicrowave.co.uksaid: Unfortunately Keysight have now sold all the cables, but do have the front panel overlay which is arguably the most critical item. Spending £500 on 5 cables and a front panel overly is more attractive than spending £8000 on an upgrading the model. For £500, I'll bet you can get a good hand crimp tool, some good coax, and a handful of connectors. Yes, but I have no way to test them. I don't have a 2.4 mm connector gage, and I am not keen to put 2.4 mm plugs into something very expensive without checking the pin depth first. I don't have a 2.4 mm cal kit, so I can't check the return loss. I would really like to find a male 2.4 mm connector gage and satisfy myself the cables, even if I get them professionally made. I believe someone might have some 2.4 mm HP cables. I can put the SMA on and at least check the pin depth. Dave. ___ 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] What sort of oscillator is this?
On 30 Sep 2014 08:46, REEVES Paul paul.ree...@uk.thalesgroup.com wrote: David, Just a thought but have you tried Pasternack? They do 'custom' precision cabling including 2.4mm connector options. regards, Paul, G8GJA Hi Paul, I don't know how good Pasternack are - I have seen some rather dubious connectors from them. But I did contact their UK agents yesterday and asked for a quote. I found another company on the web, that does connectors as small as 1.0 mm. The fact that they do such connectors gives me a bit of confidence they know what they are doing. Since I will need to bend some cables, I might try to beg, borrow or steal a 2.4 mm connector gage. I have seen so many new items with out of spec connectors, I have a healthy skepticism of connectors, and any keen not to connect a dodgy connector to expensive items. One of my ex employers would send out dodgy connectors, in the expectation a customer would not check them. I am pretty sure that adding these cables will degrade the dynamic range a little, although the specs of the instrument with without direct sampler access are the same. On the 40 GHz version of this instrument, I think the specification is degraded a bit. So I am keen for the cables to be as good as possible. At least I know I could have trusted the cables from Agilent - I am less convinced about Pasternack. I am kicking myself as 3 of the four 2.4 mm cables were available from Agilent a year ago. Now they are all sold. They would have been preferable as they would have the necessary bends in place. 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] What sort of oscillator is this?
On 9/30/14, 12:44 AM, REEVES Paul wrote: David, Just a thought but have you tried Pasternack? They do 'custom' precision cabling including 2.4mm connector options. regards, Paul, G8GJA Rather than Pasternack, you might find the following sources useful Citrus Cables does nice quality, inexpensive work, and they have oddball stuff like MMCX if you need it. I use them for general purpose jumpers a lot. http://www.citruscables.com or http://www.citruscables.biz RFCoax - I use them for semi-rigid and formable type cables http://rfcoax.com Tensolite (part of Carlisle) http://www.carlisleit.com/products/assemblies/rfmicrowave-assemblies Formable semirigid Axon http://www.axon-cable.com These guys are in the UK, and they have very low loss cable. I don't know about one-off assemblies. ___ 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] What sort of oscillator is this?
On 29 September 2014 22:45, Bob Camp kb...@n1k.org wrote: Hi The information came from the HP data sheet on the oscillator. They provide it to the people who manufacture the oscillators for them. Bob Can you share the data sheet? Dave On Sep 29, 2014, at 1:14 PM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: On 29 Sep 2014 17:58, Bob Raker bob.ra...@gmail.com wrote: It is a low end OCXO - uses AT cut crystal. 15V @ 300 mA. Warm-up time is 6 minutes max for .1 ppm. Other specs as indicated in previous emails. Has NO EFC. Where do you get this information from? I think I am going to take the covers off this soon, as I am keen to get direct access to the samplers. Unfortunately Keysight have now sold all the cables, but do have the front panel overlay which is arguably the most critical item. When I do, I will photograph the oscillator. 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] What sort of oscillator is this?
On 30 Sep 2014 14:16, Jim Lux jim...@earthlink.net wrote: On 9/30/14, 12:44 AM, REEVES Paul wrote: David, Just a thought but have you tried Pasternack? They do 'custom' precision cabling including 2.4mm connector options. regards, Paul, G8GJA Rather than Pasternack, you might find the following sources useful I got a quote from Pasternack today. They can't do 20 GHz in SMA so suggested 3.5 mm, which would be fine. They actually quited for 2.92 mm on the other end, whereas I need 2.4 mm, but the price was the US equivalent of about $220/cable. Citrus Cables does nice quality, inexpensive work, and they have oddball stuff like MMCX if you need it. I use them for general purpose jumpers a lot. http://www.citruscables.com or http://www.citruscables.biz They don't seem to do the high precision stuff. They have things like BNC and reverse SMA, but I don't see 2.4 mm. RFCoax - I use them for semi-rigid and formable type cables http://rfcoax.com Someone else suggested them. They do what I want, and the price is much lower than Pasternack. $85-$95 depending on the length, and that includes test data. I would feel a bit happier paying $5 extra for test data. Hopefully it means that they really are tested! They also do the really high frequency 1.0 mm connectors, so it gives me some confidence that they are serious about cables. Tensolite (part of Carlisle) http://www.carlisleit.com/products/assemblies/rfmicrowave-assemblies Formable semirigid Axon http://www.axon-cable.com These guys are in the UK, and they have very low loss cable. I don't know about one-off assemblies. I will ask. I am certain that this mod will degrade the dynamic range, but when it was calibrated, it exceeded the spec by about 8 dB, so a bit of loss can be tolerated. But the benefits far outweigh that. 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] What sort of oscillator is this?
On 9/30/14, 4:56 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: On 30 Sep 2014 14:16, Jim Lux jim...@earthlink.net wrote: On 9/30/14, 12:44 AM, REEVES Paul wrote: David, Just a thought but have you tried Pasternack? They do 'custom' precision cabling including 2.4mm connector options. regards, Paul, G8GJA Rather than Pasternack, you might find the following sources useful I got a quote from Pasternack today. They can't do 20 GHz in SMA so suggested 3.5 mm, which would be fine. They actually quited for 2.92 mm on the other end, whereas I need 2.4 mm, but the price was the US equivalent of about $220/cable. Citrus Cables does nice quality, inexpensive work, and they have oddball stuff like MMCX if you need it. I use them for general purpose jumpers a lot. http://www.citruscables.com or http://www.citruscables.biz They don't seem to do the high precision stuff. They have things like BNC and reverse SMA, but I don't see 2.4 mm. You might send them an email and ask. They've kind of got two sides to the business. RFCoax - I use them for semi-rigid and formable type cables http://rfcoax.com Someone else suggested them. They do what I want, and the price is much lower than Pasternack. $85-$95 depending on the length, and that includes test data. I would feel a bit happier paying $5 extra for test data. Hopefully it means that they really are tested! They also do the really high frequency 1.0 mm connectors, so it gives me some confidence that they are serious about cables. I've been very happy with the cables we've gotten from RF Coax. We do a lot at 32 and 34 GHz, and yes, getting the test data for the cables is nice. Their turnaround is relatively fast, too. Tensolite (part of Carlisle) http://www.carlisleit.com/products/assemblies/rfmicrowave-assemblies Formable semirigid Axon http://www.axon-cable.com These guys are in the UK, and they have very low loss cable. I don't know about one-off assemblies. I will ask. I am certain that this mod will degrade the dynamic range, but when it was calibrated, it exceeded the spec by about 8 dB, so a bit of loss can be tolerated. But the benefits far outweigh that. 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] What sort of oscillator is this?
It is a low end OCXO - uses AT cut crystal. 15V @ 300 mA. Warm-up time is 6 minutes max for .1 ppm. Other specs as indicated in previous emails. Has NO EFC. BR On Sun, Sep 28, 2014 at 7:26 PM, Tom Van Baak t...@leapsecond.com wrote: There were two responses to Dave's question (TCXO and OCXO) and perhaps neither is correct. I don't have a 8720D VNA myself and Dave wisely doesn't want to spoil his calibration seals by opening up his instrument to take a look inside. So here's my guess based on the clues. Agilent 8719D, 8720D, and 8722D Network Analyzers Data Sheet http://literature.cdn.keysight.com/litweb/pdf/5964-9133E.pdf Base spec: Stability 0 °C to 55 °C ±7.5 ppm C Per year (aging) ±3 ppm C Option 1D5: Stability 0 °C to 55 °C ±0.05 ppm C Per year (aging) ±0.5 ppm C Installation Note 8719D, 8720D, and 8722D Network Analyzer Option 1D5 High Stability Frequency Reference Upgrade Kit http://literature.cdn.keysight.com/litweb/pdf/08720-90318.pdf High-stability frequency reference output (Option 1D5) Frequency: 10. MHz Frequency stability (0 °C to 55 °C): ±0.05 ppm Daily aging rate (after 30 days): 3 x 10–9/day Yearly aging rate: 0.5 ppm/year Output: 0 dBm minimum Nominal output impedance: 50 ohms To me, these specs are a bit better than all XO and most TCXO I've seen used in test equipment. But the specs are a bit worse than most OCXO I've run across. So which is it, TCXO or OCXO? The next clue is the attached photo found at: Agilent 08753-60158 Opt. 1D5 for 8753D/E/ES http://www.ebay.com/itm/151256172424 So we're looking for the specs for a Corning oscillator, P/N MC599X4. I didn't find much on the web (one link called it a controlled oscillator). Does anyone have information on this? It looks too large for a XO or TCXO. MC might be McCoy. Or, if MC indicates MCXO (Microcomputer Compensated crystal Oscillator) then that would nicely explain the shape/size and why the specs are in between a really good TCXO and a not so good OCXO. Some photos of the inside of a MCXO (not necessarily the one in question) here: http://design.ecs.psu.edu/2.0/Design/design_images/MCXO1.jpg http://design.ecs.psu.edu/2.0/Design/projects2.html (scroll down to MCXO) /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] What sort of oscillator is this?
On 29 Sep 2014 17:58, Bob Raker bob.ra...@gmail.com wrote: It is a low end OCXO - uses AT cut crystal. 15V @ 300 mA. Warm-up time is 6 minutes max for .1 ppm. Other specs as indicated in previous emails. Has NO EFC. Where do you get this information from? I think I am going to take the covers off this soon, as I am keen to get direct access to the samplers. Unfortunately Keysight have now sold all the cables, but do have the front panel overlay which is arguably the most critical item. When I do, I will photograph the oscillator. 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] What sort of oscillator is this?
drkir...@kirkbymicrowave.co.uk said: Unfortunately Keysight have now sold all the cables, but do have the front panel overlay which is arguably the most critical item. Spending £500 on 5 cables and a front panel overly is more attractive than spending £8000 on an upgrading the model. For £500, I'll bet you can get a good hand crimp tool, some good coax, and a handful of connectors. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What sort of oscillator is this?
Hi The information came from the HP data sheet on the oscillator. They provide it to the people who manufacture the oscillators for them. Bob On Sep 29, 2014, at 1:14 PM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: On 29 Sep 2014 17:58, Bob Raker bob.ra...@gmail.com wrote: It is a low end OCXO - uses AT cut crystal. 15V @ 300 mA. Warm-up time is 6 minutes max for .1 ppm. Other specs as indicated in previous emails. Has NO EFC. Where do you get this information from? I think I am going to take the covers off this soon, as I am keen to get direct access to the samplers. Unfortunately Keysight have now sold all the cables, but do have the front panel overlay which is arguably the most critical item. When I do, I will photograph the oscillator. 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] What sort of oscillator is this?
On 29 Sep 2014 20:06, Hal Murray hmur...@megapathdsl.net wrote: drkir...@kirkbymicrowave.co.uksaid: Unfortunately Keysight have now sold all the cables, but do have the front panel overlay which is arguably the most critical item. Spending £500 on 5 cables and a front panel overly is more attractive than spending £8000 on an upgrading the model. For £500, I'll bet you can get a good hand crimp tool, some good coax, and a handful of connectors. Yes, but I have no way to test them. I don't have a 2.4 mm connector gage, and I am not keen to put 2.4 mm plugs into something very expensive without checking the pin depth first. I don't have a 2.4 mm cal kit, so I can't check the return loss. I would really like to find a male 2.4 mm connector gage and satisfy myself the cables, even if I get them professionally made. I believe someone might have some 2.4 mm HP cables. I can put the SMA on and at least check the pin depth. Dave. ___ 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] What sort of oscillator is this?
On 28 Sep 2014 03:11, Alexander Pummer alex...@ieee.org wrote: that is most likelly a TXCO, what is in the user's manual about warm up time? Two people responded - one says a OCXO and the other an TCXO!! The warmup time is I think an hour, but clearly that is not the time for an oven to warm up. If it was a frequency counter then I think the warmup time would be just that of the oscillator, as really I can't see much other than the oscillator needing to be stable. But on a VNA one needs the temperature of cables to be stable, as expansion of cables is likely to cause phase instability. So the time for the cables lengths to stabilise is probably much longer than it would take an oven to stabilise. if they have a special precise reference -- like for spectrum analyzer or frequency counter that would have at least one magnitude better stability I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. But I think HP did this sort of thing a lot. Something that would have cost very little to add, became an expensive option. In some cases these expensive options are nothing more than enabling a bit of software, although the RD cost of the software is probably a lot more than the hardware cost of adding a better oscillator. 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] What sort of oscillator is this?
drkir...@kirkbymicrowave.co.uk said: Two people responded - one says a OCXO and the other an TCXO!! The warmup time is I think an hour, but clearly that is not the time for an oven to warm up. An hour seems like a reasonable OCXO warm-up time to me. You might get faster warm-up times, but you will probably pay for it someplace else. Here is a graph: http://www.megapathdsl.net/~hmurray/time-nuts/Drift-ocxo3mhz-a.gif Also, it probably depends upon how long it has been powered off. See how much power the system draws when plugged in but turned off. Most gear using OCXOs keep them powered up when the front panel switch says off. So 0 is a strong indication that you have a TCXO. You can also unplug it for a couple of hours, then watch the power after you plug it in. I'd expect a step decrease in power after the core is mostly warm. I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. Maybe most customers have a good lab source of 10 MHz and use an external clock. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What sort of oscillator is this?
The temperature stability and warm-up time imply an OCXO. 0.05ppm over 0-55C is at the limit of what can be achieved with a TCXO but they do not have a long warm-up time. It would be expensive and only would be used if warm-up time was critical. The HP high-stability options are (almost?) always OCXOs. David On 9/28/14 6:16 AM, Hal Murray wrote: drkir...@kirkbymicrowave.co.uk said: Two people responded - one says a OCXO and the other an TCXO!! The warmup time is I think an hour, but clearly that is not the time for an oven to warm up. An hour seems like a reasonable OCXO warm-up time to me. You might get faster warm-up times, but you will probably pay for it someplace else. Here is a graph: http://www.megapathdsl.net/~hmurray/time-nuts/Drift-ocxo3mhz-a.gif Also, it probably depends upon how long it has been powered off. See how much power the system draws when plugged in but turned off. Most gear using OCXOs keep them powered up when the front panel switch says off. So 0 is a strong indication that you have a TCXO. You can also unplug it for a couple of hours, then watch the power after you plug it in. I'd expect a step decrease in power after the core is mostly warm. I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. Maybe most customers have a good lab source of 10 MHz and use an external clock. ___ 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] What sort of oscillator is this?
I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. But I think HP did this sort of thing a lot. Something that would have cost very little to add, became an expensive option. In some cases these expensive options are nothing more than enabling a bit of software, although the RD cost of the software is probably a lot more than the hardware cost of adding a better oscillator. Dave. I worked for the HP Santa Clara Division for 19 years. The reason why a customer would NOT want a precision oscillator in a high end instrument would be that he was going to use a house standard. At my division in those days, we had an ensemble of cesiums disciplined by LORAN that distributed a 10 MHz signal around the plant. We supposedly had the most accurate clock on the west coast. We of course made OCXO's at SCD and sold them to other HP divisions. It would not be impossible for a division to use a TCXO, but it would be out of character given that we transferred 10811's at cost, which was then about $400. Rick Karlquist N6RK ___ 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] What sort of oscillator is this?
On 28 September 2014 15:52, David McGaw n1...@dartmouth.edu wrote: The temperature stability and warm-up time imply an OCXO. 0.05ppm over 0-55C is at the limit of what can be achieved with a TCXO but they do not have a long warm-up time. It would be expensive and only would be used if warm-up time was critical. The HP high-stability options are (almost?) always OCXOs. David For what it is worth, the calibration certificate indicates the oscillator was warmed up for at least 48 hours, but the spec on the instrument shows nothing like that. Here's the latest cal certificate from Keysight. http://www.kirkbymicrowave.co.uk/cal_certificates/Keysight-standard-calibration-with-uncertainties-for-8720D-vector-network-analyzer-16-09-2014.pdf Note the section on the last page OPT 1D5 HI STAB TIMEBASE PASSED Elapsed time after power-on: 48 h Here's the previous one from Agilent. http://www.kirkbymicrowave.co.uk/cal_certificates/Agilent-standard-calibration-with-uncertainties-for-8720D-vector-network-analyzer.pdf It sort of implies they left it on for 48 hours since it has that oscillator, but I can't see anything in the specs to say it needs 48 hours to warm up. BTW, you may note Keysight's uncertainty for measurement of the 10 MHz reference in September 2014 is 0.0010 Hz, whereas Agilent's was 0.00080 Hz in August 2013. They 5071A primary frequency standard. I assume the fact that the ID number is UK13623 on both certiciates, means it is actually the same standard, rather than two of the same model number. 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] What sort of oscillator is this?
On 28/09/2014 17:44, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: BTW, you may note Keysight's uncertainty for measurement of the 10 MHz reference in September 2014 is 0.0010 Hz, whereas Agilent's was 0.00080 Hz in August 2013. They 5071A primary frequency standard. I assume the fact that the ID number is UK13623 on both certiciates, means it is actually the same standard, rather than two of the same model number. It seems the same unit, I doubt they will maintain the ID if replacing it, but it has been re-cablibrated between both certificates, so its uncertainity has evolved from the previous calibration to the last one. Regards, Javier ___ 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] What sort of oscillator is this?
Hal, An ocxo has two effects that cause a frequency change after power on: heater stabilization and crystal retrace. Heaters usually stabilize quickly (1 - 2 minutes for DIP-14 ocxo, 7 to 10 minutes for typical eurocan docxo's) and then a. ~30 minutes soak until the ocxo starts following ambient temperature. After the initial warmup the crystal goes into an exponential retrace as it out-gasses etc and it can take many hours or even days or weeks for that to subside. Then what is left is typically linear aging. Bye, Said Sent From iPhone On Sep 28, 2014, at 3:16, Hal Murray hmur...@megapathdsl.net wrote: drkir...@kirkbymicrowave.co.uk said: Two people responded - one says a OCXO and the other an TCXO!! The warmup time is I think an hour, but clearly that is not the time for an oven to warm up. An hour seems like a reasonable OCXO warm-up time to me. You might get faster warm-up times, but you will probably pay for it someplace else. Here is a graph: http://www.megapathdsl.net/~hmurray/time-nuts/Drift-ocxo3mhz-a.gif Also, it probably depends upon how long it has been powered off. See how much power the system draws when plugged in but turned off. Most gear using OCXOs keep them powered up when the front panel switch says off. So 0 is a strong indication that you have a TCXO. You can also unplug it for a couple of hours, then watch the power after you plug it in. I'd expect a step decrease in power after the core is mostly warm. I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. Maybe most customers have a good lab source of 10 MHz and use an external clock. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What sort of oscillator is this?
Looks like I am having crow for lunch today. I did find the 1D5 installation instructions and at first it looked like the standard OCXO package used in many HP instruments. But some closer reading shows that it may in fact be a 50 MHz TCXO. Tom - Original Message - From: Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, September 28, 2014 4:57 AM Subject: Re: [time-nuts] What sort of oscillator is this? On 28 Sep 2014 03:11, Alexander Pummer alex...@ieee.org wrote: that is most likelly a TXCO, what is in the user's manual about warm up time? Two people responded - one says a OCXO and the other an TCXO!! The warmup time is I think an hour, but clearly that is not the time for an oven to warm up. If it was a frequency counter then I think the warmup time would be just that of the oscillator, as really I can't see much other than the oscillator needing to be stable. But on a VNA one needs the temperature of cables to be stable, as expansion of cables is likely to cause phase instability. So the time for the cables lengths to stabilise is probably much longer than it would take an oven to stabilise. if they have a special precise reference -- like for spectrum analyzer or frequency counter that would have at least one magnitude better stability I find it odd that an instrument that probably cost $50,000 when new did not have a TCXO as standard, and perhaps an oven as an option. But I think HP did this sort of thing a lot. Something that would have cost very little to add, became an expensive option. In some cases these expensive options are nothing more than enabling a bit of software, although the RD cost of the software is probably a lot more than the hardware cost of adding a better oscillator. 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] What sort of oscillator is this?
On 28 September 2014 19:37, Tom Miller tmiller11...@verizon.net wrote: Looks like I am having crow for lunch today. I did find the 1D5 installation instructions and at first it looked like the standard OCXO package used in many HP instruments. But some closer reading shows that it may in fact be a 50 MHz TCXO. Tom I had not seen that document but found it once you mentioned it. I assume that there must be some frequency division taking place, as it puts 10 MHz out the back. 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] What sort of oscillator is this?
There were two responses to Dave's question (TCXO and OCXO) and perhaps neither is correct. I don't have a 8720D VNA myself and Dave wisely doesn't want to spoil his calibration seals by opening up his instrument to take a look inside. So here's my guess based on the clues. Agilent 8719D, 8720D, and 8722D Network Analyzers Data Sheet http://literature.cdn.keysight.com/litweb/pdf/5964-9133E.pdf Base spec: Stability 0 °C to 55 °C ±7.5 ppm C Per year (aging) ±3 ppm C Option 1D5: Stability 0 °C to 55 °C ±0.05 ppm C Per year (aging) ±0.5 ppm C Installation Note 8719D, 8720D, and 8722D Network Analyzer Option 1D5 High Stability Frequency Reference Upgrade Kit http://literature.cdn.keysight.com/litweb/pdf/08720-90318.pdf High-stability frequency reference output (Option 1D5) Frequency: 10. MHz Frequency stability (0 °C to 55 °C): ±0.05 ppm Daily aging rate (after 30 days): 3 x 10–9/day Yearly aging rate: 0.5 ppm/year Output: 0 dBm minimum Nominal output impedance: 50 ohms To me, these specs are a bit better than all XO and most TCXO I've seen used in test equipment. But the specs are a bit worse than most OCXO I've run across. So which is it, TCXO or OCXO? The next clue is the attached photo found at: Agilent 08753-60158 Opt. 1D5 for 8753D/E/ES http://www.ebay.com/itm/151256172424 So we're looking for the specs for a Corning oscillator, P/N MC599X4. I didn't find much on the web (one link called it a controlled oscillator). Does anyone have information on this? It looks too large for a XO or TCXO. MC might be McCoy. Or, if MC indicates MCXO (Microcomputer Compensated crystal Oscillator) then that would nicely explain the shape/size and why the specs are in between a really good TCXO and a not so good OCXO. Some photos of the inside of a MCXO (not necessarily the one in question) here: http://design.ecs.psu.edu/2.0/Design/design_images/MCXO1.jpg http://design.ecs.psu.edu/2.0/Design/projects2.html (scroll down to MCXO) /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What sort of oscillator is this?
Dave, do you have access to a good counter? If so, you could profile the warm-up characteristic of the reference from a cold start. Then you would know if an oven is involved. Tom - Original Message - From: Tom Van Baak t...@leapsecond.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, September 28, 2014 7:26 PM Subject: Re: [time-nuts] What sort of oscillator is this? There were two responses to Dave's question (TCXO and OCXO) and perhaps neither is correct. I don't have a 8720D VNA myself and Dave wisely doesn't want to spoil his calibration seals by opening up his instrument to take a look inside. So here's my guess based on the clues. Agilent 8719D, 8720D, and 8722D Network Analyzers Data Sheet http://literature.cdn.keysight.com/litweb/pdf/5964-9133E.pdf Base spec: Stability 0 °C to 55 °C ±7.5 ppm C Per year (aging) ±3 ppm C Option 1D5: Stability 0 °C to 55 °C ±0.05 ppm C Per year (aging) ±0.5 ppm C Installation Note 8719D, 8720D, and 8722D Network Analyzer Option 1D5 High Stability Frequency Reference Upgrade Kit http://literature.cdn.keysight.com/litweb/pdf/08720-90318.pdf High-stability frequency reference output (Option 1D5) Frequency: 10. MHz Frequency stability (0 °C to 55 °C): ±0.05 ppm Daily aging rate (after 30 days): 3 x 10–9/day Yearly aging rate: 0.5 ppm/year Output: 0 dBm minimum Nominal output impedance: 50 ohms To me, these specs are a bit better than all XO and most TCXO I've seen used in test equipment. But the specs are a bit worse than most OCXO I've run across. So which is it, TCXO or OCXO? The next clue is the attached photo found at: Agilent 08753-60158 Opt. 1D5 for 8753D/E/ES http://www.ebay.com/itm/151256172424 So we're looking for the specs for a Corning oscillator, P/N MC599X4. I didn't find much on the web (one link called it a controlled oscillator). Does anyone have information on this? It looks too large for a XO or TCXO. MC might be McCoy. Or, if MC indicates MCXO (Microcomputer Compensated crystal Oscillator) then that would nicely explain the shape/size and why the specs are in between a really good TCXO and a not so good OCXO. Some photos of the inside of a MCXO (not necessarily the one in question) here: http://design.ecs.psu.edu/2.0/Design/design_images/MCXO1.jpg http://design.ecs.psu.edu/2.0/Design/projects2.html (scroll down to MCXO) /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] What sort of oscillator is this?
On 29 Sep 2014 02:05, Tom Miller tmiller11...@verizon.net wrote: Dave, do you have access to a good counter? Not really. I have an HP 7 modular measurement system, which has all the bits for a 22 GHz spectrum analyzer. The analyzer has a frequency counter mode, but I have not written any software to grab data from it. However, I once had a contract where I wrote some code to collect data from another HP 7 system, so it should be a fairly easy thing to do. I am not sure how well it works as a frequency counter. I do have an 18 GHz counter, but it doesn't have a high stability oscillator, has no GPIB and has an intermittent fault. The 7 series has the optional high stability time base, which is definitely an oven. A red light comes up when the oven is cold. BTW, for the 7 series you need to have the oven in order to lock the system to an external reference. One of the options for the high stability time base is to delete the oven. Strangly some eBay sellers have been known to have both and ask more for the one which has the option which deletes the oven! If so, you could profile the warm-up characteristic of the reference from a cold start. I will try to do that. It might take me a bit of time as I need to do some things that earn me money. They are of somewhat higher priority! 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] What sort of oscillator is this?
On 29 Sep 2014 00:27, Tom Van Baak t...@leapsecond.com wrote: The next clue is the attached photo found at: Agilent 08753-60158 Opt. 1D5 for 8753D/E/ES http://www.ebay.com/itm/151256172424 Note that is for an 8753 (3/6 GHz) series VNA, not the 8719/20/22, which are 13.5, 20 and 40 GHz respectively. I am on my mobile phone at the minute, but if the specs of the 8753 and 8720 series oscillators are the same, then perhaps they are the same oscillator. There's more chance of finding out from the Keysight forum information about the 8753s, as Joel Dunsmore, is very active on the forums and was one of the designers of the 8753. But I am not aware of any individual who designed the 8720 series. Being a lot less popular than the 8753s, there's generally less public information about the 8720 series. The 8753 and 8720 were made in the same factory, look similar and have firmware which looks similar, so it would not surprise me if they use the same oscillator. When I am in front of a computer with a decent size screen, I will compare the specs of the oscillators in the two units, but with only a mobile phone to hand, I will not do it now. 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] What sort of oscillator is this?
There's also this installation note: http://literature.cdn.keysight.com/litweb/pdf/08720-90318.pdf Bob - AE6RV On 09/28/2014 06:26 PM, Tom Van Baak wrote: There were two responses to Dave's question (TCXO and OCXO) and perhaps neither is correct. I don't have a 8720D VNA myself and Dave wisely doesn't want to spoil his calibration seals by opening up his instrument to take a look inside. So here's my guess based on the clues. Agilent 8719D, 8720D, and 8722D Network Analyzers Data Sheet http://literature.cdn.keysight.com/litweb/pdf/5964-9133E.pdf Base spec: Stability 0 °C to 55 °C ±7.5 ppm C Per year (aging) ±3 ppm C Option 1D5: Stability 0 °C to 55 °C ±0.05 ppm C Per year (aging) ±0.5 ppm C Installation Note 8719D, 8720D, and 8722D Network Analyzer Option 1D5 High Stability Frequency Reference Upgrade Kit http://literature.cdn.keysight.com/litweb/pdf/08720-90318.pdf High-stability frequency reference output (Option 1D5) Frequency: 10. MHz Frequency stability (0 °C to 55 °C): ±0.05 ppm Daily aging rate (after 30 days): 3 x 10–9/day Yearly aging rate: 0.5 ppm/year Output: 0 dBm minimum Nominal output impedance: 50 ohms To me, these specs are a bit better than all XO and most TCXO I've seen used in test equipment. But the specs are a bit worse than most OCXO I've run across. So which is it, TCXO or OCXO? The next clue is the attached photo found at: Agilent 08753-60158 Opt. 1D5 for 8753D/E/ES http://www.ebay.com/itm/151256172424 So we're looking for the specs for a Corning oscillator, P/N MC599X4. I didn't find much on the web (one link called it a controlled oscillator). Does anyone have information on this? It looks too large for a XO or TCXO. MC might be McCoy. Or, if MC indicates MCXO (Microcomputer Compensated crystal Oscillator) then that would nicely explain the shape/size and why the specs are in between a really good TCXO and a not so good OCXO. Some photos of the inside of a MCXO (not necessarily the one in question) here: http://design.ecs.psu.edu/2.0/Design/design_images/MCXO1.jpg http://design.ecs.psu.edu/2.0/Design/projects2.html (scroll down to MCXO) /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] What sort of oscillator is this?
The 70k SA should work fine. Just warm it up, set it for center freq. 10.00 MHz, span 5 or 10 kHz. Feed in the 10 MHz reference and power the cold 8720 up. If it comes up near centered in a few seconds and does not change much, you have a TCXO. If way off frequency and drifting towards 10 MHz, it's an OCXO. How is it that a time-nut does not have a counter? (just kidding). - Original Message - From: Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, September 28, 2014 9:43 PM Subject: Re: [time-nuts] What sort of oscillator is this? On 29 Sep 2014 02:05, Tom Miller tmiller11...@verizon.net wrote: Dave, do you have access to a good counter? Not really. I have an HP 7 modular measurement system, which has all the bits for a 22 GHz spectrum analyzer. The analyzer has a frequency counter mode, but I have not written any software to grab data from it. However, I once had a contract where I wrote some code to collect data from another HP 7 system, so it should be a fairly easy thing to do. I am not sure how well it works as a frequency counter. I do have an 18 GHz counter, but it doesn't have a high stability oscillator, has no GPIB and has an intermittent fault. The 7 series has the optional high stability time base, which is definitely an oven. A red light comes up when the oven is cold. BTW, for the 7 series you need to have the oven in order to lock the system to an external reference. One of the options for the high stability time base is to delete the oven. Strangly some eBay sellers have been known to have both and ask more for the one which has the option which deletes the oven! If so, you could profile the warm-up characteristic of the reference from a cold start. I will try to do that. It might take me a bit of time as I need to do some things that earn me money. They are of somewhat higher priority! 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] What sort of oscillator is this?
The 10 MHz high stability oscillator (option 1D5) in my HP 8720D VNA has the following specs Stability 0 to 55 deg C, +-/ 0.05 ppm Aging per year +/- 0.5 ppm What sort of oscillator is this likely to be - TCXO or OCXO? Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ 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] What sort of oscillator is this?
OCXO - Original Message - From: Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, September 27, 2014 5:36 PM Subject: [time-nuts] What sort of oscillator is this? The 10 MHz high stability oscillator (option 1D5) in my HP 8720D VNA has the following specs Stability 0 to 55 deg C, +-/ 0.05 ppm Aging per year +/- 0.5 ppm What sort of oscillator is this likely to be - TCXO or OCXO? Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ 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] What sort of oscillator is this?
that is most likelly a TXCO, what is in the user's manual about warm up time? if they have a special precise reference -- like for spectrum analyzer or frequency counter that would have at least one magnitude better stability and would have OXCO,a good OXCO like the Milliren 260 series or the double oven oscillators from Morion [St Petersburg, Russia] ones --if they are always heated and have good power supply-- could have 3 x 10^-10 stability 73 Alex On 9/27/2014 2:36 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: The 10 MHz high stability oscillator (option 1D5) in my HP 8720D VNA has the following specs Stability 0 to 55 deg C, +-/ 0.05 ppm Aging per year +/- 0.5 ppm What sort of oscillator is this likely to be - TCXO or OCXO? Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ 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.
