Re: [time-nuts] ADEV measurement question
To learn more, I think the best way would be to put the counter into its fast binary mode and acquire 1k time interval samples per second. That would give me loads of data to play with and it would be easy to try out how different averaging schemes affect the result. Matthias, See: http://leapsecond.com/pages/adev-avg/ for the results of a similar ADEV averaging experiment. I can send you the raw data if you want. What helped me understand the issue was to think in terms of frequency *in*stability instead of frequency stability. We often use the words interchangeably. But imagine that your goal is to measure oscillator noise, its instability, not its stability. With this new mental image the last thing you would do is average. By its very nature, averaging removes highs and lows and smoothes things out. If your goal is to measure instability, averaging removes the very thing you're trying to measure. The plots in the above web page show this dramatically. You can make an oscillator as good as you want if you average enough. /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] Vanguard Ultra precision Golden Oscillator
H I think I'm convinced, I had my doubts to start with and now have enough more to ensure I follow a different route:-) Regards Nigel GM8PZR Hi If they are indeed grabbing anything in that package and re-labeling it, I would be very careful. True TCXO’s (full compensation network) in that package are relatively rare compared to the enormous number of “precision XO’s” made in the same package. The XO’s had no real compensation. They simply relied on a packaged crystal to deliver a tighter stability than the open blank DIP XO’s of the same era. The other obvious issue of a relabel process would be that the one I get and review likely has no relation at all to the one you get and try to use. We could have parts each built to totally different specs and each made by who knows who. Bob ___ 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] Running voltages through MVAR (In re: HP5065)
I have decided it is finally time to come clean about one of my trade secrets: I sometimes run voltages through MVAR. Sometimes I also run temperatures, kilowatts and anything else I happen to have a time-series of through the MVAR. In this case, it tells us a lot about why the C-field current of my HP5065 is unstable: http://phk.freebsd.dk/hacks/HP5065A/20150822_mvar/index.html I'm not done collecting data for the resulting effect on the HP5065 performance, but so far it looks like the MVAR floor is half of what it used to be. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Vanguard Ultra precision Golden Oscillator
Hi I think the lead length on the parts argues against them being pulls from boards. It does *not* eliminate the possibility. I’ve seen low cost manufacture that never did any lead trim. I would not put it at the top of my list for “fancy oscillator of the year”. The price is high enough that you could put together a fairly nice un-compensated XO from parts for much less money. If it *is* an XO, you are paying a lot for it. Bob On Aug 23, 2015, at 12:30 PM, GandalfG8--- via time-nuts time-nuts@febo.com wrote: H I think I'm convinced, I had my doubts to start with and now have enough more to ensure I follow a different route:-) Regards Nigel GM8PZR Hi If they are indeed grabbing anything in that package and re-labeling it, I would be very careful. True TCXO’s (full compensation network) in that package are relatively rare compared to the enormous number of “precision XO’s” made in the same package. The XO’s had no real compensation. They simply relied on a packaged crystal to deliver a tighter stability than the open blank DIP XO’s of the same era. The other obvious issue of a relabel process would be that the one I get and review likely has no relation at all to the one you get and try to use. We could have parts each built to totally different specs and each made by who knows who. Bob ___ 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] DIY Time-Nut Night Stand
For the time-nut that has everything ... IKEA RAST Night Stand - $15 http://www.ikea.com/us/en/catalog/products/44361109/ Hacking the IKEA RAST http://www.instructables.com/id/8U-Rack-Case-From-IKEA-RAST-Table/?ALLSTEPS A few changes/suggestions: 1. IF you only need a 6U night stand, consider flipping it as an option -- especially if you desire another equipment piece on top , like the Masterclock TCD 26 (big night stand clock display) AkroBins storage containers https://akro-mils.com/Products/Types/Plastic-Storage-Containers/AkroBins 2. Raxxess Rack Rails, better choice (6U or 8U). Sold at Guitar Center retail stores, Amazon, etc. http://www.amazon.com/Raxxess-Rack-Rails-Black-Space/dp/B000K6B38C 3. If you desire casters, threaded inserts for the pine wood would be a better idea. 4. Power strip could be added to rear of cabinet (vertical or horizontal mounting), to reduce cord clutter. w9gb Sent from iPad Air ___ 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] Vanguard Ultra precision Golden Oscillator
Hi Tim, Thanks for your comments and I did wonder about the plating, in the photo for the auction number I gave I couldn't decide if the bottom of the can was corroded or just badly plated. Regards Nigel GM8PZR Mainstream TCXO's moved entirely to surface-mount many years ago. These Vanguard DIP units have to be washed/replated RFE parts. It's a shame they are so completely relabeled because the original manufacturer/part number is nowhere to be found, and I'm sure this lost info would be interesting to a time-nut. They seem to be especially popular with audiophools (probably the gold). Tim N3QE ___ 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] Vanguard Ultra precision Golden Oscillator
From the way the descriptions read, there must be a audiofool in there somewhere On Sun, Aug 23, 2015 at 5:16 AM, Tim Shoppa tsho...@gmail.com wrote: Mainstream TCXO's moved entirely to surface-mount many years ago. These Vanguard DIP units have to be washed/replated RFE parts. It's a shame they are so completely relabeled because the original manufacturer/part number is nowhere to be found, and I'm sure this lost info would be interesting to a time-nut. They seem to be especially popular with audiophools (probably the gold). Tim N3QE On Sun, Aug 23, 2015 at 4:59 AM, GandalfG8--- via time-nuts time-nuts@febo.com wrote: The Vanguard ultra precision Golden TCXO, their description not mine:-), has been listed on Ebay for a while now at various frequencies, and the 0.1 ppm spec caught my eye as a possible replacement for the around 6 or 7 ppm oscillator in a DDS function generator I've been using. One typical current auction, for a 25MHz unit, is 111071283814. Has anybody tried any of these and/or come across any more data elsewhere? Regards Nigel GM8PZR ___ 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] Vanguard Ultra precision Golden Oscillator
Hi Bob, Just the sort of things I was wondering and lot's of questions indeed, that's why I asked, I didn't want to be the guinea pig:-) Regards Nigel GM8PZR Hi A few things I would wonder about: 1) Is it 0.1 ppm over 0 to 50C (or some other range)? If not, what is the temperature stability? 2) Does it run at 3.3V -or- at 5V (pick one) or do they run equally well at either voltage? 3) Since there is no EFC, is 0.1 ppm the set tolerance? If it’s not, what is the initial accuracy? Lots of questions, there’s not much information there. That may be due to the seller not having the information. It also may just be because nobody ever asked. The term TCXO can mean a variety of things to a different people …. The most encouraging thing is that there *is* a phase noise spec on it. Bob ___ 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] Running voltages through MVAR (In re: HP5065)
Poul-Henning, I abuse ADEV too! It really works well in some cases, doesn't it. Very clever of you to try it on a 5065A with voltage, current. etc. I assume you use the y-form (frequency) not the x-form (phase) in this case? Notes: 1) The scale is more intuitive, I find, when sqrt is used -- so I'm curious why you chose MVAR instead of MDEV? 2) When plots mostly head down with a -1 slope, consider TDEV instead of MDEV, which effectively rotates by 45 degrees turning -1 slopes into 0 slopes. For some kinds of data a rise above a normal (zero) slope is more informative than a bend of a steep -1 line. Psychologically too, it removes the things are working better and better as time goes on impression that happens with a -1 slope, e.g., when ADEV is used on data from a locked loop. 3) Before you settle on MDEV, also try ADEV. There are cases where the massive averaging inside of MDEV ruins interesting noise periodics that would show up in ADEV. Then if you want to combine (2) and (3) you can compute ADEV(tau) * tau. Look at http://leapsecond.com/tools/adev5.c for the undocumented z flag. Like the real TDEV is to MDEV, this is a sort of TDEV for ADEV, but without the sqrt(3). It plots a zero slope where ADEV would plot a -1 slope. /tvb - Original Message - From: Poul-Henning Kamp p...@phk.freebsd.dk To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, August 23, 2015 11:16 AM Subject: [time-nuts] Running voltages through MVAR (In re: HP5065) I have decided it is finally time to come clean about one of my trade secrets: I sometimes run voltages through MVAR. Sometimes I also run temperatures, kilowatts and anything else I happen to have a time-series of through the MVAR. In this case, it tells us a lot about why the C-field current of my HP5065 is unstable: http://phk.freebsd.dk/hacks/HP5065A/20150822_mvar/index.html I'm not done collecting data for the resulting effect on the HP5065 performance, but so far it looks like the MVAR floor is half of what it used to be. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Tracor 599 for sale in Italy
Hello All. I just stumbled upon this announce (I'm not the seller and I'm not related to him in any way) for a Tracor 599k VLF/LF tracking receiver with manual included. It has a chart plotter for phase difference. http://www.kijiji.it/annunci/altro-elettronica/pistoia-annunci-buggiano/tracor-599k-vlf-lf-receiver/80388385 Andrea ___ 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] Vanguard Ultra precision Golden Oscillator
Mainstream TCXO's moved entirely to surface-mount many years ago. These Vanguard DIP units have to be washed/replated RFE parts. It's a shame they are so completely relabeled because the original manufacturer/part number is nowhere to be found, and I'm sure this lost info would be interesting to a time-nut. They seem to be especially popular with audiophools (probably the gold). Tim N3QE On Sun, Aug 23, 2015 at 4:59 AM, GandalfG8--- via time-nuts time-nuts@febo.com wrote: The Vanguard ultra precision Golden TCXO, their description not mine:-), has been listed on Ebay for a while now at various frequencies, and the 0.1 ppm spec caught my eye as a possible replacement for the around 6 or 7 ppm oscillator in a DDS function generator I've been using. One typical current auction, for a 25MHz unit, is 111071283814. Has anybody tried any of these and/or come across any more data elsewhere? Regards Nigel GM8PZR ___ 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] Vanguard Ultra precision Golden Oscillator
Hi A few things I would wonder about: 1) Is it 0.1 ppm over 0 to 50C (or some other range)? If not, what is the temperature stability? 2) Does it run at 3.3V -or- at 5V (pick one) or do they run equally well at either voltage? 3) Since there is no EFC, is 0.1 ppm the set tolerance? If it’s not, what is the initial accuracy? Lots of questions, there’s not much information there. That may be due to the seller not having the information. It also may just be because nobody ever asked. The term TCXO can mean a variety of things to a different people …. The most encouraging thing is that there *is* a phase noise spec on it. Bob On Aug 23, 2015, at 4:59 AM, GandalfG8--- via time-nuts time-nuts@febo.com wrote: The Vanguard ultra precision Golden TCXO, their description not mine:-), has been listed on Ebay for a while now at various frequencies, and the 0.1 ppm spec caught my eye as a possible replacement for the around 6 or 7 ppm oscillator in a DDS function generator I've been using. One typical current auction, for a 25MHz unit, is 111071283814. Has anybody tried any of these and/or come across any more data elsewhere? Regards Nigel GM8PZR ___ 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] Vanguard Ultra precision Golden Oscillator
The Vanguard ultra precision Golden TCXO, their description not mine:-), has been listed on Ebay for a while now at various frequencies, and the 0.1 ppm spec caught my eye as a possible replacement for the around 6 or 7 ppm oscillator in a DDS function generator I've been using. One typical current auction, for a 25MHz unit, is 111071283814. Has anybody tried any of these and/or come across any more data elsewhere? Regards Nigel GM8PZR ___ 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] Trimble GPS board
On Sat, 22 Aug 2015 18:25:04 -0400, you wrote: rbenward at verizon.net wrote: See below, here is a 73090 OCXO (same as on some of those GPSDO boards) powered by +12V. You are incorrect in your assumption that the link you have supplied shows a 73090 OCXO powered by +12VDC. The BOARD is indeed powered by 12VDC (or 15VDC if you read the listing) but if you look at all the photos you will see a 3-terminal regulator on the bottom of the pc board. Hi, It does indeed have a reg, but as far as I can see it's a 7812 that's in the picture in the listing. This would also explain why it has a 12V or 15V selector link. I'm not suggesting that it's a 12V osc - on my 57963-80 it is definitely fed just 5V from the regulator. I also used 6V for the power supply. It also appears just to be a basic, fast warm-up AT OCXO, which fits in with the short time constant on the GPS control loop. Angus. The Trimble GPSDO I'm supplying 6.3VDC to had a 5 volt regulator that has a measured output of 5.00VDC and the supply pin on the oscillator had that 5.00VDC on it, not the 6.3VDC from my supply. A continuity check shows a direct connection from the regulator's 5 volt output directly to the oscillator's supply pin. Because of the higher current drawn by the 5 volt oven, running the input to the board at 12VDC and wasting all that power as heat would not be wise. 6.3VDC makes me happy and they chose a LDO regulator for a good reason. The one error I did notice is I said the board locked after it found satellites but that is incorrect. It does find satellites quickly but takes about 10 minutes to lock and that is when the 10Mhz output is enabled. I did some of my checking around 1AM and that is not a good time for clear thinking or writing. -Arthur ___ 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] Trimble GPS board
Hi The gotcah (as many here have found out the hard way) is that the OCXO is indeed a +5V part and not a +12V unit. Apparently the internal Chinese market has them mis-labeld. That bleeds over into the listings you see on eBay. There are a *lot* of mistaken listings …. Bob On Aug 22, 2015, at 2:02 PM, Bob rbenw...@verizon.net wrote: Hi Arthur, Thank you for this information. I have not received my board yet, I probably still have a few weeks to go. The LT1764 will take up to 20V, but I would never go to the edge. You could easily do 12V, the only downside is the dissipation in the LT17654. Use a variable power supply and raise the voltage slowly. Monitor the temperature with a thermocouple, IR spot meter (radio shack had one for $10), or just use your finger. If you can keep your finger on it comfortable for a long period of time, the temp should be OK. The junction temp is rated for 125C. Now on the flips side, my only concern is the regulator is not supplying the oven power. Most Trimble OCXOs I see on Ebay are powered by +12. When supplying only 6.5V the oven might not get up to temp producing frequency instability and some erratic EFC stats. See below, here is a 73090 OCXO (same as on some of those GPSDO boards) powered by +12V. It's possible the regulator is meant to be powered from +12V, supplying power to the digital logic and to the oscillator portion of the OCXO. Then +12V directly supplies the oven. http://www.ebay.com/itm/10-00MHz-Trimble-Double-Oven-OCXO-Trimble-73090-Double-sinewave-15V-12V-/251883335405?hash=item3aa56aaeed I will post my success and let everyone know how I make out. I purchased this to have a backup for my Z3801 Z3805. Both are on the fritz, I will be post those trials and tribulations on a new thread. Thanks so much for your response. Bob ___ 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] Trimble GPS board
Hi Bob, I got a Trimble 57963-80 last year and the 73090 OXCO and some other parts on it are supplied with 5V from the LT1764A. The DSP, FPGA, etc., also have various small regulators supplying their supply voltages - one even has a dropper resistor in series. These are connected to the main input supply, so raising it above what it should be is probably not a good idea. I thought at first that the LT1764A would be thermally connected to the fixing hole beside it so that the heat could be removed, but it is only connected to the copper on the top of board at that point - then again, that may be the way it was mounted. I did put a temp sensor on the 1764 to see how much it heated up during warm up and when running, but neither looked close to being a problem when run at 6V and room temperature. At 6V, it took 2A during warm up and just over 1A when running at room temp, but the warm up is fast. When I got the board, someone had written on the OCXO with a marker pen what the pins were, and the power was marked as 12V, and an EFC voltage was also written on (about 0.2V from what I measured) which was all a little weird. It was listed as having been tested, but since the seller said that they had no connection info, who tested it and how is anyone's guess... Angus. On Sat, 22 Aug 2015 14:02:35 -0400, you wrote: Hi Arthur, Thank you for this information. I have not received my board yet, I probably still have a few weeks to go. The LT1764 will take up to 20V, but I would never go to the edge. You could easily do 12V, the only downside is the dissipation in the LT17654. Use a variable power supply and raise the voltage slowly. Monitor the temperature with a thermocouple, IR spot meter (radio shack had one for $10), or just use your finger. If you can keep your finger on it comfortable for a long period of time, the temp should be OK. The junction temp is rated for 125C. Now on the flips side, my only concern is the regulator is not supplying the oven power. Most Trimble OCXOs I see on Ebay are powered by +12. When supplying only 6.5V the oven might not get up to temp producing frequency instability and some erratic EFC stats. See below, here is a 73090 OCXO (same as on some of those GPSDO boards) powered by +12V. It's possible the regulator is meant to be powered from +12V, supplying power to the digital logic and to the oscillator portion of the OCXO. Then +12V directly supplies the oven. http://www.ebay.com/itm/10-00MHz-Trimble-Double-Oven-OCXO-Trimble-73090-Double-sinewave-15V-12V-/251883335405?hash=item3aa56aaeed I will post my success and let everyone know how I make out. I purchased this to have a backup for my Z3801 Z3805. Both are on the fritz, I will be post those trials and tribulations on a new thread. Thanks so much for your response. Bob ___ 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] Trimble GPS board
On the left front corner of the board is the 1 PPS connector. To the right of that connector are 4 unpopulated holes for a connector. I traced those out and found 2 went to a RS-232 chip that appears to be a different type depending on which of the boards you receive. The left hole is ground (RS-232 pin 5 on the computer end), then the next hole is not connected, then RS-232 pin 2, then pin 3 being the hole with the square index pad on the right. Using a terminal emulator program and 57600 8N1N I was able to communicate with the board. Typing '?' will give you a long list of all the commands it will accept. For instance, 'STAT' and 'POSSTAT' are 2 of the commands that will give you info on how the board is working. Typing *IDN? at the UCCM-P prompt returns 57964-60 for my board and POSSTAT shows up to 12 satellites can be tracked. The date code on my unit is 2009. The board seems to work well but the OCXO runs pretty hot so it probably isn't a double oven. The multicontact connector probably has most of the functions and LED signals available but I couldn't see using it so I'll get whatever signals I want directly off the pc board. Hi Arthur, That's interesting - I connected my one up to Trimble studio and others, but got no joy - I never thought of just asking it :) I went through the connections on the other pins, but most are just to the FPGA or 0V. Most don't appear to be doing a lot - maybe they need whatever is meant to be connected to this board to be connected before they do anything. There is another serial port which is the same baud rate but appears to be binary, and prattles away every 2 seconds: Pin 36 goes to Pin 4 of the UART (RX) Pin 37 goes to Pin 8 of the UART (TX) Pin 2 has binary data of about 64 bits at 1.6us/bit - looks like maybe a timer or similar. (Above pin numbers assume V+ is connected to pins 44-50 and are hopefully correct, but always worth checking) Angus. ___ 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] Vanguard Ultra precision Golden Oscillator
Hi If they are indeed grabbing anything in that package and re-labeling it, I would be very careful. True TCXO’s (full compensation network) in that package are relatively rare compared to the enormous number of “precision XO’s” made in the same package. The XO’s had no real compensation. They simply relied on a packaged crystal to deliver a tighter stability than the open blank DIP XO’s of the same era. The other obvious issue of a relabel process would be that the one I get and review likely has no relation at all to the one you get and try to use. We could have parts each built to totally different specs and each made by who knows who. Bob On Aug 23, 2015, at 8:16 AM, Tim Shoppa tsho...@gmail.com wrote: Mainstream TCXO's moved entirely to surface-mount many years ago. These Vanguard DIP units have to be washed/replated RFE parts. It's a shame they are so completely relabeled because the original manufacturer/part number is nowhere to be found, and I'm sure this lost info would be interesting to a time-nut. They seem to be especially popular with audiophools (probably the gold). Tim N3QE On Sun, Aug 23, 2015 at 4:59 AM, GandalfG8--- via time-nuts time-nuts@febo.com wrote: The Vanguard ultra precision Golden TCXO, their description not mine:-), has been listed on Ebay for a while now at various frequencies, and the 0.1 ppm spec caught my eye as a possible replacement for the around 6 or 7 ppm oscillator in a DDS function generator I've been using. One typical current auction, for a 25MHz unit, is 111071283814. Has anybody tried any of these and/or come across any more data elsewhere? Regards Nigel GM8PZR ___ 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] Running voltages through MVAR (In re: HP5065)
Poul-Henning, Using ADEV and MDEV, and indeed TDEV as TVB points out, for analyzing other physical signals than phase/frequency is maybe not very common, but if Kocher if you know your field well enough. David Allan and I discuss this every once in a while. ADEV/MDEV and friends is really the statistical tools to analyze and separate noises of different slopes. Together with the bias functions you can use it to verify you have the white noise you assume, and only then you can rightfully make use of that property to meet the intention of GUM. Flicker noise is indeed one such noise-form that does require better tooling. Don't forget to use FFT as well as analyzing non-repetitive systematic trends. I'd love to see the raw data more closely. So keep up the good work. Cheers, Magnus On 08/23/2015 08:16 PM, Poul-Henning Kamp wrote: I have decided it is finally time to come clean about one of my trade secrets: I sometimes run voltages through MVAR. Sometimes I also run temperatures, kilowatts and anything else I happen to have a time-series of through the MVAR. In this case, it tells us a lot about why the C-field current of my HP5065 is unstable: http://phk.freebsd.dk/hacks/HP5065A/20150822_mvar/index.html I'm not done collecting data for the resulting effect on the HP5065 performance, but so far it looks like the MVAR floor is half of what it used to be. ___ 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] Vanguard Ultra precision Golden Oscillator
I can't imagine that anyone would trust some 0.1 ppm specification just because an unknown party stamped that on the case. There are many sellers of very similarly marked oscillators. They all are selling in single quantities for about the same price. The market seems to be hobbyists, especially audio fanatics who want to reduce the jitter in their audio gear. Since no reputable manufacturer would purchase such gray market parts with zero reputation (no known manufacturer of the item), nobody will be performing incoming inspection on these devices. So nobody knows what they are getting - if they install it and it isn't on frequency how would the buyer know what was wrong? Notice that there does not appear to be a Vanguard oscillator company or trade name used by some other manufacturer. The units are not marked with a model number. There is no real datasheet or specifications. There is no description of what the 0.1 ppm refers to, but it's printed right there on the case so it appears to be an attempt to give the product some type of quality. The obviously flouting of eBay and international customs regulations also shows the lack of trust you should have in that seller. Shipping invoice will be declared with low value and mark as 'gift' or 'samples' See the eBay rules: http://pages.ebay.com/help/pay/international-shipping-rules.html Note: It's illegal to falsify customs declarations or mark an item as a gift in order to avoid customs fees. If a buyer asks you to commit customs fraud, report it to us. If the seller is faking custom forms, how do you know that anything they say is true? -- Bill Byrom N5BB ___ 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] picPET, Raspberry Pi, Logging, and a GPS module
Evening all, Months ago, I bought several picPET's from Tom Van Baak: http://leapsecond.com/pic/picpet2.htm Plan was to set up a power line phase measurement system using my Z3801 GPSDO as the 10 MHz input. Life intervened...and finally got back to that project today. I decided to do preliminary playing around to make sure I got everything working right before I hooked it up to the Z3801 and a transformer that would sample the line frequency. Tom included a nice little 10 MHz oscillator unit, so I got to work using that as the 10 MHz reference...and searching around for something to use as an event pulse, I found a GPS unit that had what I suspected to be a 0.5 PPS output. (two birds, one stone!) The collection device was to be a Raspberry Pi computer as they are simple, cheap, and in my experience, work pretty well. First thing to do on the RPi was to disable the serial console so that I could use those UART pins as the serial input. There are a number of automated way to do that online. Second thing to do was to get serial into the RPi and display it. Found another script to do that online. Initially the output from the picPET was garbage, but thankfully I was using a pP05 and pulling pin 4 high made the text readable. Third thing to do was to get some sort of serial logging program. I found one called grabserial. http://elinux.org/Grabserial Grabserial is nice because it has a lot of options that will make it nice to use in an automated fashion. IE: I can tell it to collect for X seconds, record to a file, then terminate, plus log the system clock for giggles. Grabserial gave me fits! Turns out that it doesn't pass the command line switch for the RPi serial port somehow, but editing the source to reflect /dev/ttyAMA0 as the serial port made it work. (I submitted an issue on github to the development team to see if I'm an idiot or if this is a real issue) Fourth thing was to figure out how to name files using the time and date so I don't have data file collisions. Studying the date command yielded an answer: now=$(date +%Y-%m-%d__%k-%M-%S) python grabserial.py -e 30 -t -T -v -o log.$now.log This names the log file log.YEAR-MONTH-DAY__HOUR-MIN-SEC.log which is mighty handy. Next up - setting up a chron job to run the above once per day so I get one data file per day, keeping the file size manageable. Also need to get Samba working so I can pull the data files off the RPi onto the PC for manipulation. :) thanks much and 73, ben, kd5byb ___ 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] Vanguard Ultra precision Golden Oscillator
Hi I just spent some “quality time” looking at what Mouser offers in the way of crystal oscillators. None of this work was NIST certified. Others could do the same thing. You have a number of candidates in the “dip clock” stability category both in traditional (leaded) and modern (SMT) packages. They are at “basement experimenter” sort of prices ($20 down to under $1). I would not trust any of them as a legit standard for a project. Next up are a number of products from people who are very proud of what they are selling. The prices are 10 to 50X higher than the simple product ( $200). To me that puts them out of the basement experiment category. When I look at what $50 gets me on eBay, I sort of wonder why you would go that way on an a one off design. In the middle, there are a surprisingly small number of products. There are a few OCXO’s and a few TCXO’s. The pickings are pretty slim. If I need something like an odd frequency …good luck in that range. The bottom line is that there really aren’t a lot of choices. It’s nice to use “real parts” with “real specs”. The nature of the distribution process is that there is a (basement incompatible ) markup on exotic parts. It’s not limited in any way to oscillators. Volume matters and volume on exotic items is never going to happen. So what to do: 1) Off to eBay 2) Spend a fortune on the legit part 3) Make your own There is not a lot to an un-compensated crystal oscillator. Tuning it on frequency is fairly simple. Even for odd frequencies Mouser will happily sell you a crystal for next to nothing. Toss in a handful of parts and you have a very respectable oscillator. For a basement project … much better than spending $40 on something suspect from who knows who. Bob On Aug 23, 2015, at 6:07 PM, Bill Byrom t...@radio.sent.com wrote: I can't imagine that anyone would trust some 0.1 ppm specification just because an unknown party stamped that on the case. There are many sellers of very similarly marked oscillators. They all are selling in single quantities for about the same price. The market seems to be hobbyists, especially audio fanatics who want to reduce the jitter in their audio gear. Since no reputable manufacturer would purchase such gray market parts with zero reputation (no known manufacturer of the item), nobody will be performing incoming inspection on these devices. So nobody knows what they are getting - if they install it and it isn't on frequency how would the buyer know what was wrong? Notice that there does not appear to be a Vanguard oscillator company or trade name used by some other manufacturer. The units are not marked with a model number. There is no real datasheet or specifications. There is no description of what the 0.1 ppm refers to, but it's printed right there on the case so it appears to be an attempt to give the product some type of quality. The obviously flouting of eBay and international customs regulations also shows the lack of trust you should have in that seller. Shipping invoice will be declared with low value and mark as 'gift' or 'samples' See the eBay rules: http://pages.ebay.com/help/pay/international-shipping-rules.html Note: It's illegal to falsify customs declarations or mark an item as a gift in order to avoid customs fees. If a buyer asks you to commit customs fraud, report it to us. If the seller is faking custom forms, how do you know that anything they say is true? -- Bill Byrom N5BB ___ 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] Vanguard Ultra precision Golden Oscillator
The most encouraging thing is that there *is* a phase noise spec on it. BUT its seems to be the same spec on all irrespective of carrier frequency which goes from to 6MHz to 100MHz, with similar design the time jitter may be somewhat similar but I'd be astonished if the phase noise was common to all (implying grossly different time jitter). In addition, the package would worry me, 4 pins all with a glass seal, I want the ground pin to be directly connected to the case to minimise ground inductance leading to issues like injection locking. I'd assume these are cheap and cheerful clock oscillators, similar can be bought with a known brand label and spec from Digikey etc for less $. David --- Message: 14 Date: Sun, 23 Aug 2015 08:33:59 -0400 From: Bob Camp kb...@n1k.org To: gandal...@aol.com, Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Vanguard Ultra precision Golden Oscillator Message-ID: 86abcf10-fc65-4713-b286-bdc3e33fe...@n1k.org Content-Type: text/plain; charset=utf-8 Hi A few things I would wonder about: 1) Is it 0.1 ppm over 0 to 50C (or some other range)? If not, what is the temperature stability? 2) Does it run at 3.3V -or- at 5V (pick one) or do they run equally well at either voltage? 3) Since there is no EFC, is 0.1 ppm the set tolerance? If it’s not, what is the initial accuracy? Lots of questions, there’s not much information there. That may be due to the seller not having the information. It also may just be because nobody ever asked. The term TCXO can mean a variety of things to a different people …. The most encouraging thing is that there *is* a phase noise spec on it. Bob ___ 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] Running voltages through MVAR (In re: HP5065)
In message 85E3D5A82F314700BCA6493EEF245CCF@pc52, Tom Van Baak writes: 1) The scale is more intuitive, I find, when sqrt is used -- so I'm curious why you chose MVAR instead of MDEV? Actually the plot is MDEV now that I think of it... I've added a footnote. 2) When plots mostly head down with a -1 slope, consider TDEV instead of MDEV, which effectively rotates by 45 degrees turning -1 slopes into 0 slopes. For some kinds of data a rise above a normal (zero) slope is more informative than a bend of a steep -1 line. Psychologically too, it removes the things are working better and better as time goes on impression that happens with a -1 slope, e.g., when ADEV is used on data from a locked loop. Good point. 3) Before you settle on MDEV, also try ADEV. There are cases where the massive averaging inside of MDEV ruins interesting noise periodics I generally hunt periodics with FFTs, but yes, ADEV is useful for the sort of almost has a stable frequency like HVAC's turning on/off etc. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Vanguard Ultra precision Golden Oscillator
On Sun, 23 Aug 2015 12:13:47 -0400, you wrote: Thanks for your comments and I did wonder about the plating, This looks like the same package the Chinese are selling for the Kenwood TS-590 to upgrade the already good internal timebase. The reports on them are pretty good, though few have an environmental chamber to see what the compensation really does. The plating seems to cost extra. I got a break on a genuine Kenwood one, and it holds quite well in a pretty uniform cellar ham shack. When last I checked, it was about 4Hz off 10MHz WWV; not enough to take off the bottom cover and tweak. -- Gary Woods AKA K2AHC- PGP key on request, or at home.earthlink.net/~garygarlic Zone 5/4 in upstate New York, 1420' elevation. NY WO G ___ 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] Vanguard Ultra precision Golden Oscillator
Hi If all the spec’s on it are lies, then of course they don’t help much at all. I have not contacted the seller with any questions. I have no idea if there is more data on the parts or not. Some parts from other sellers with very similar markings have quite good paper specs associated with them. There are technologies that have been used on similar products over the years that result in parts that do not meet that phase noise spec at any point in the frequency range from 6 to 100 MHz. Those are the parts that you probably don’t want to use on your DDS clock. The spec he states is quite do-able over that range without a lot of effort on an XO. Who knows if he meets it or not. I certainly know of no reason why he could not do so. He might exceed the spec by quite a bit at one end … The header production process is a fraction of a cent cheaper if you use all glass seals than if you weld one of the leads. In that case, you simply hand weld a ground onto the base. A bit ugly, but they save money. Inductance wise, not much difference. It’s miles ahead of any of the modern ceramic packages in terms of shielding either way. Bob On Aug 23, 2015, at 2:55 PM, David t_list_1_o...@braw.co.uk wrote: The most encouraging thing is that there *is* a phase noise spec on it. BUT its seems to be the same spec on all irrespective of carrier frequency which goes from to 6MHz to 100MHz, with similar design the time jitter may be somewhat similar but I'd be astonished if the phase noise was common to all (implying grossly different time jitter). In addition, the package would worry me, 4 pins all with a glass seal, I want the ground pin to be directly connected to the case to minimise ground inductance leading to issues like injection locking. I'd assume these are cheap and cheerful clock oscillators, similar can be bought with a known brand label and spec from Digikey etc for less $. David --- Message: 14 Date: Sun, 23 Aug 2015 08:33:59 -0400 From: Bob Camp kb...@n1k.org To: gandal...@aol.com, Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Vanguard Ultra precision Golden Oscillator Message-ID: 86abcf10-fc65-4713-b286-bdc3e33fe...@n1k.org Content-Type: text/plain; charset=utf-8 Hi A few things I would wonder about: 1) Is it 0.1 ppm over 0 to 50C (or some other range)? If not, what is the temperature stability? 2) Does it run at 3.3V -or- at 5V (pick one) or do they run equally well at either voltage? 3) Since there is no EFC, is 0.1 ppm the set tolerance? If it’s not, what is the initial accuracy? Lots of questions, there’s not much information there. That may be due to the seller not having the information. It also may just be because nobody ever asked. The term TCXO can mean a variety of things to a different people …. The most encouraging thing is that there *is* a phase noise spec on it. Bob ___ 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] Vanguard Ultra precision Golden Oscillator
kb...@n1k.org said: There is not a lot to an un-compensated crystal oscillator. Tuning it on frequency is fairly simple. Even for odd frequencies Mouser will happily sell you a crystal for next to nothing. Toss in a handful of parts and you have a very respectable oscillator. For a basement project ⦠much better than spending $40 on something suspect from who knows who. What's magic about a crystal as compared to an osc? Is it really easier to get an odd-ball frequency in a crystal vs an osc? The last time I bought a special frequency osc was over 10 years ago. Once I found the right company, things were simple. I don't remember the price. At the time, it seemed reasonable, but that was for a commercial project rather than a basement lab. Do those companies still exist or have they all fallen through the cracks of higher volumes and lower prices. -- 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.
