Re: [time-nuts] 5370B OCXO
Hi I guess the real question is what a better OCXO would have actually cost. If the 60111 was a test ten, get ten sort of thing (I'm guessing it was) - was a better part simply a test 10 get 9 issue? The claim was made that short term stability testing could be done directly in the aging racks. It's not real clear what the actual cost of an extended test / sort would have been. Bob On Mar 11, 2010, at 10:43 PM, John Miles wrote: Many if not most 5370-based measurements are based on differential timing between the START and STOP channels, and wouldn't benefit from a better 10 MHz reference. If a customer did need something better, they probably already had a house standard to pipe in the back... and if not, HP would have been able to sell them one. It made more sense to keep the cost down by not including a high-end OCXO that would have gone unappreciated by most users. The 5370's jitter+resolution floor doesn't allow it to reach 1E-11 at t=1s in any event, so the -60111 wouldn't have been the limiting factor in the short term. One valid question, though, is why they bothered to put the nicer 10811-60109 OCXOs in the post-2120 series 5065A models, where its short-term performance is hosed by tying it to the rubidium reference with a ~1 Hz loop. Those 5065As would have been OK with a -60111, at least in the pre-2632 serial #s with the original integrator board. I'd be curious to know if they lowered the loop BW when they respun the integrator PCB. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Bob Camp Sent: Thursday, March 11, 2010 7:11 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 5370B OCXO Hi The OCXO in the 5370B is a 10811-60111. The only added spec on it is a 1x10^-11 ADEV spec at 1 second. By modern standards that's not a real tight spec. There are other 10811's with tighter specs on them at 1 second. My guess is that it was not a real tight spec for the 10811 to hit. The short term would appear to contribute to the total error on the counter. Why not put a better oscillator in 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. ___ 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] Time-nuts digests.
Hi. Anyone else using the digest delivery method, seeing gaps in delivery? Like, today, issue #54 turned up OK, but prior to that, the last one was issue #49! Looking in the message archive, there does not seem to be enough messages to justify for 4 full digest mails. I often see 1 go missing once or twice a week, but 4 in one hit? Not in spam bucket, and filters are set to allow it through. Curious... Dave B. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt antenna?
I use one like eBay item 290369619357. I have it attached to the corner of my workshop roof which is under a canopy of trees. It is connected through about 25 feet of Belden 9913F7 and it works like a champ. Relatively inexpensive if it gets taken out by a storm. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Dave hartzell Sent: Thursday, March 11, 2010 10:23 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Thunderbolt antenna? Hello, I'm looking for a decent outdoor antenna for my Thunderbolt... I need to graduate beyond the puck-antenna in the window sill. Any recommendations and/or sources (the lower cost, the better of course!)? Thanks, 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] 5370B OCXO
If I understand this thread correctly. I would speculate it was simply a business choice. 1 less part type to manage. On Fri, Mar 12, 2010 at 7:30 AM, Bob Camp li...@rtty.us wrote: Hi I guess the real question is what a better OCXO would have actually cost. If the 60111 was a test ten, get ten sort of thing (I'm guessing it was) - was a better part simply a test 10 get 9 issue? The claim was made that short term stability testing could be done directly in the aging racks. It's not real clear what the actual cost of an extended test / sort would have been. Bob On Mar 11, 2010, at 10:43 PM, John Miles wrote: Many if not most 5370-based measurements are based on differential timing between the START and STOP channels, and wouldn't benefit from a better 10 MHz reference. If a customer did need something better, they probably already had a house standard to pipe in the back... and if not, HP would have been able to sell them one. It made more sense to keep the cost down by not including a high-end OCXO that would have gone unappreciated by most users. The 5370's jitter+resolution floor doesn't allow it to reach 1E-11 at t=1s in any event, so the -60111 wouldn't have been the limiting factor in the short term. One valid question, though, is why they bothered to put the nicer 10811-60109 OCXOs in the post-2120 series 5065A models, where its short-term performance is hosed by tying it to the rubidium reference with a ~1 Hz loop. Those 5065As would have been OK with a -60111, at least in the pre-2632 serial #s with the original integrator board. I'd be curious to know if they lowered the loop BW when they respun the integrator PCB. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Bob Camp Sent: Thursday, March 11, 2010 7:11 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 5370B OCXO Hi The OCXO in the 5370B is a 10811-60111. The only added spec on it is a 1x10^-11 ADEV spec at 1 second. By modern standards that's not a real tight spec. There are other 10811's with tighter specs on them at 1 second. My guess is that it was not a real tight spec for the 10811 to hit. The short term would appear to contribute to the total error on the counter. Why not put a better oscillator in 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. ___ 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] ko4bb monitor
Arthur, I did some reverse engineering in the units I bought from Amazon. I got the schematics and it looks like the communication is by means of I2C. If somebody is interested let me know and I'll send him the schematics. Regards, Ignacio, EB4APL - EB4APL wrote: Arthur, I received the units I bought from Amazon. I was planning to normally use them in the front panel of future projects in the same way you did with the fluke.1 unit, but now I wonder if you or somebody else figured out how to communicate with the original iCruze units. Maybe they are programmed to be just a 2 line ASCII serial display, because in that case they can be used for a variety of monitoring tasks without modification, just tailoring the data to be understandable by the module. I powered one of my units and found it sends a 5 to 0 volts negative going pulse of about 2 ms every 1.6 s on the yellow wire, but I didn't tried to send anything to the green wire yet. Regards, Ignacio, EB4APL -- Arthur Dent wrote: Although the Icruze module fluke.l sells is in a nice package for mounting on the dash of a car, I chose to build it into the same case as I did the Thunderbolt, power supply, and distribution amplifier. The power and RS-232 signal for the display is tapped off the p.c. board of the thunderbolt so the RS-232 connector on the back is still free to be used with my computer to monitor the unit. The 10Mhz output from the T-bolt has a BNC jumper to the input of the distribution amplifier that has 3 Q-bit amps 1 unamplified output that allows me to monitor the output of the T-bolt directly. Here are two photos of the unit I threw together. I think it makes a nice inexpensive GPSDO package. Inside http://farm3.static.flickr.com/2715/4307285530_4222e414ff_o.jpg Front http://farm3.static.flickr.com/2798/4307285448_1921a16b26_o.jpg In the photo of the front of the unit, to the right of the T-bolt, is a RFTG-u Ref 1 (HP Z3811 with a MTI 260 OCXO) that I modified to run correctly without the interface cable and companion Ref 0 unit. That has a nice stable 5Mhz output feeding a FE-7921A 5Mhz distribution amp. I’m using a Philips PM6680 counter with an X72 Rb timebase and aPhilips PM3375 scope for quick frequency checks. Works quite well to compare the 2 GPSDOs. ___ 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] ko4bb monitor
In a message dated 12/03/2010 16:35:02 GMT Standard Time, eb4...@cembreros.jazztel.es writes: I did some reverse engineering in the units I bought from Amazon. I got the schematics and it looks like the communication is by means of I2C. If somebody is interested let me know and I'll send him the schematics. ___ 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] ko4bb monitor
Whoops Sorry about that, hit wrong button and sent in error. Nigel GM8PZR - In a message dated 12/03/2010 17:12:25 GMT Standard Time, gandal...@aol.com writes: In a message dated 12/03/2010 16:35:02 GMT Standard Time, eb4...@cembreros.jazztel.es writes: I did some reverse engineering in the units I bought from Amazon. I got the schematics and it looks like the communication is by means of I2C. If somebody is interested let me know and I'll send him the schematics. ___ 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] 5370B OCXO
Hi Tough to believe that HP worried a lot about SKU inflation back when they did the 5370 :) I'm assuming that the 5370 was a Santa Clara design. That would put the counter designers down the hall from the oscillator factory. Unlikely that there was a communications gap about what could or could not be done. You may well be correct though. Setting up and managing another part is the most likely reason why not to add a couple more tests. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Friday, March 12, 2010 8:51 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5370B OCXO If I understand this thread correctly. I would speculate it was simply a business choice. 1 less part type to manage. On Fri, Mar 12, 2010 at 7:30 AM, Bob Camp li...@rtty.us wrote: Hi I guess the real question is what a better OCXO would have actually cost. If the 60111 was a test ten, get ten sort of thing (I'm guessing it was) - was a better part simply a test 10 get 9 issue? The claim was made that short term stability testing could be done directly in the aging racks. It's not real clear what the actual cost of an extended test / sort would have been. Bob On Mar 11, 2010, at 10:43 PM, John Miles wrote: Many if not most 5370-based measurements are based on differential timing between the START and STOP channels, and wouldn't benefit from a better 10 MHz reference. If a customer did need something better, they probably already had a house standard to pipe in the back... and if not, HP would have been able to sell them one. It made more sense to keep the cost down by not including a high-end OCXO that would have gone unappreciated by most users. The 5370's jitter+resolution floor doesn't allow it to reach 1E-11 at t=1s in any event, so the -60111 wouldn't have been the limiting factor in the short term. One valid question, though, is why they bothered to put the nicer 10811-60109 OCXOs in the post-2120 series 5065A models, where its short-term performance is hosed by tying it to the rubidium reference with a ~1 Hz loop. Those 5065As would have been OK with a -60111, at least in the pre-2632 serial #s with the original integrator board. I'd be curious to know if they lowered the loop BW when they respun the integrator PCB. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Bob Camp Sent: Thursday, March 11, 2010 7:11 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 5370B OCXO Hi The OCXO in the 5370B is a 10811-60111. The only added spec on it is a 1x10^-11 ADEV spec at 1 second. By modern standards that's not a real tight spec. There are other 10811's with tighter specs on them at 1 second. My guess is that it was not a real tight spec for the 10811 to hit. The short term would appear to contribute to the total error on the counter. Why not put a better oscillator in 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. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] 5370B OXCO
Referencing the performance of 10811 variants really does not help make a good evaluation. You need to measure a particular oscillator to see what it really does. I have rack mounted a 10811-60111 that I use as a short term stability reference. This particular one is consistent with: 1 sec 6.14X10-13th 10 sec 3.52X10-13th 100 sec 3.35X10-13th This of course is a selected unit, but after testing MANY of the different variants it is one of a small percentage of excellent ones. Using it as a counter time base would be a waste! Corby Dawson Love Spell Click here to light up your life with a love spell! http://thirdpartyoffers.juno.com/TGL2141/c?cp=NHEBWbJpRL7hhUMxZQOpngAAJ1ABLZFyqoH-WnHH1GJ345whAAYAAADNRwA= ___ 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] Self-contained divider board/design available?
Hello Everyone, I warn you, this is a topic that has been discussed before... I enjoyed ko4bb's high level description of oscillator stability measurement (http://www.ko4bb.com/Timing/FAQ-1.php). Now I am looking into getting or putting together a self contained divider board that will allow me to make T.I. measurements at the PPS rate from a 10MHz reference using a HP 5370A counter. I am sure some of you have such boards. Are there any designs documented anywhere? Are there PCBs available? Otherwise, I have a tube full of 74AC163 sync. binary counters I believe could do the job. Intent was to put a cascade of 8 of these on a board. What recommendations would you give? I presume output re-timing is required with these devices since the TC output may have glitches, right? Is a simple NPN transistor in common-emitter configuration good enough to buffer and scale the input signal, or should I go for a tuned input? When it comes to performance, I understand there is quite a broad range of possible solutions, from the lousiest to the sharpest. My goal is to have a resonably good board that can deal with GPS-grade accuracy/stability. I don't intend to make atomic-level stability measurements (at least not for now, but who knows in the future...). ADEV measurement on GPS receivers, generators and oscillators is the objective. As you can see, this brings you back to basics. This is where I will start implementing T.I. measurements from... Thanks in advance, Bert. ps. please also reply direct, as I subscribe to Time-Nuts in the digest mode. __ Be smarter than spam. See how smart SpamGuard is at giving junk email the boot with the All-new Yahoo! Mail. Click on Options in Mail and switch to New Mail today or register for free at http://mail.yahoo.ca ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Self-contained divider board/design available?
Hi,Have you looked at Tom's PIC microcontroller based divider? See http://www.leapsecond.com/tools/PPSDIV.ASMIt's a singe chip solution with multiple outputs and synchronisation. The 10MHz is used the clock input to the PIC and the firmware flips the output after a given number of processor cycles.If you don't program PIC's There are people on the list including myself who can do it for you.If you want a kit, the TAPR TADD-2 was based on Tom's idea. Details are here http://www.tapr.org/kits_tadd-2.html Regards,Robert G8RPI --- On Fri, 12/3/10, Bert, VE2ZAZ ve2...@yahoo.ca wrote: From: Bert, VE2ZAZ ve2...@yahoo.ca Subject: [time-nuts] Self-contained divider board/design available? To: time-nuts@febo.com Date: Friday, 12 March, 2010, 19:37 Hello Everyone, I warn you, this is a topic that has been discussed before... I enjoyed ko4bb's high level description of oscillator stability measurement (http://www.ko4bb.com/Timing/FAQ-1.php). Now I am looking into getting or putting together a self contained divider board that will allow me to make T.I. measurements at the PPS rate from a 10MHz reference using a HP 5370A counter. I am sure some of you have such boards. Are there any designs documented anywhere? Are there PCBs available? Otherwise, I have a tube full of 74AC163 sync. binary counters I believe could do the job. Intent was to put a cascade of 8 of these on a board. What recommendations would you give? I presume output re-timing is required with these devices since the TC output may have glitches, right? Is a simple NPN transistor in common-emitter configuration good enough to buffer and scale the input signal, or should I go for a tuned input? When it comes to performance, I understand there is quite a broad range of possible solutions, from the lousiest to the sharpest. My goal is to have a resonably good board that can deal with GPS-grade accuracy/stability. I don't intend to make atomic-level stability measurements (at least not for now, but who knows in the future...). ADEV measurement on GPS receivers, generators and oscillators is the objective. As you can see, this brings you back to basics. This is where I will start implementing T.I. measurements from... Thanks in advance, Bert. ps. please also reply direct, as I subscribe to Time-Nuts in the digest mode. __ Be smarter than spam. See how smart SpamGuard is at giving junk email the boot with the All-new Yahoo! Mail. Click on Options in Mail and switch to New Mail today or register for free at http://mail.yahoo.ca ___ 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] 5370B OCXO
Well at least today its a very key reality. Maybe not in the 80s. But I work for a large company that has 10s of thousands of parts and its a very real drive to remove different parts for more commonality. I would bet indeed business drove the position On Fri, Mar 12, 2010 at 12:18 PM, Bob Camp li...@rtty.us wrote: Hi Tough to believe that HP worried a lot about SKU inflation back when they did the 5370 :) I'm assuming that the 5370 was a Santa Clara design. That would put the counter designers down the hall from the oscillator factory. Unlikely that there was a communications gap about what could or could not be done. You may well be correct though. Setting up and managing another part is the most likely reason why not to add a couple more tests. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Friday, March 12, 2010 8:51 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5370B OCXO If I understand this thread correctly. I would speculate it was simply a business choice. 1 less part type to manage. On Fri, Mar 12, 2010 at 7:30 AM, Bob Camp li...@rtty.us wrote: Hi I guess the real question is what a better OCXO would have actually cost. If the 60111 was a test ten, get ten sort of thing (I'm guessing it was) - was a better part simply a test 10 get 9 issue? The claim was made that short term stability testing could be done directly in the aging racks. It's not real clear what the actual cost of an extended test / sort would have been. Bob On Mar 11, 2010, at 10:43 PM, John Miles wrote: Many if not most 5370-based measurements are based on differential timing between the START and STOP channels, and wouldn't benefit from a better 10 MHz reference. If a customer did need something better, they probably already had a house standard to pipe in the back... and if not, HP would have been able to sell them one. It made more sense to keep the cost down by not including a high-end OCXO that would have gone unappreciated by most users. The 5370's jitter+resolution floor doesn't allow it to reach 1E-11 at t=1s in any event, so the -60111 wouldn't have been the limiting factor in the short term. One valid question, though, is why they bothered to put the nicer 10811-60109 OCXOs in the post-2120 series 5065A models, where its short-term performance is hosed by tying it to the rubidium reference with a ~1 Hz loop. Those 5065As would have been OK with a -60111, at least in the pre-2632 serial #s with the original integrator board. I'd be curious to know if they lowered the loop BW when they respun the integrator PCB. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com ]On Behalf Of Bob Camp Sent: Thursday, March 11, 2010 7:11 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 5370B OCXO Hi The OCXO in the 5370B is a 10811-60111. The only added spec on it is a 1x10^-11 ADEV spec at 1 second. By modern standards that's not a real tight spec. There are other 10811's with tighter specs on them at 1 second. My guess is that it was not a real tight spec for the 10811 to hit. The short term would appear to contribute to the total error on the counter. Why not put a better oscillator in 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. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Self-contained divider board/design available?
Bert Bert, VE2ZAZ wrote: Hello Everyone, I warn you, this is a topic that has been discussed before... I enjoyed ko4bb's high level description of oscillator stability measurement (http://www.ko4bb.com/Timing/FAQ-1.php). Now I am looking into getting or putting together a self contained divider board that will allow me to make T.I. measurements at the PPS rate from a 10MHz reference using a HP 5370A counter. I am sure some of you have such boards. Are there any designs documented anywhere? Are there PCBs available? Otherwise, I have a tube full of 74AC163 sync. binary counters I believe could do the job. Intent was to put a cascade of 8 of these on a board. What recommendations would you give? I presume output re-timing is required with these devices since the TC output may have glitches, right? Yes, the TC output may have glitches so it would need to be resynchronised if you use it. Alternatively you could just use the Q3 (MS bit) output of the final AC163. To divide by 1E7 you just need to preload the counters with an apprpriate value when TC on the last AC163 goes high. You need to invert TC and use this signal to drive the synchronous preload of all the AC163's in the chain. Alternatively you can configure each AC163 to divide by 10 by inverting its TC output and driving the synchronous load input with that signal. The parallel inputs need to be wired to preload a 6 into the counter whenever the synchronous load goes low. Is a simple NPN transistor in common-emitter configuration good enough to buffer and scale the input signal, or should I go for a tuned input? Depends on the input signal level. You may need to use schottky diode clamps to keep the transistor out of saturation. If the signal is large enough you can drive a CMOS inverter directly (AC coupled). Just dedicate a single chip for clock shaping don't share it with other signals. When it comes to performance, I understand there is quite a broad range of possible solutions, from the lousiest to the sharpest. My goal is to have a resonably good board that can deal with GPS-grade accuracy/stability. I don't intend to make atomic-level stability measurements (at least not for now, but who knows in the future...). ADEV measurement on GPS receivers, generators and oscillators is the objective. ACMOS has an intrinsic period jitter in the 1ps region, so the divider performance may depend more on the input signal characteristics. As you can see, this brings you back to basics. This is where I will start implementing T.I. measurements from... Thanks in advance, Bert. ps. please also reply direct, as I subscribe to Time-Nuts in the digest mode. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] iCruze displays (was ko4bb monitor)
This is about the recycled displays that fluke.l used to implement his version of the KO4BB Thunderbolt monitor and he sells on eBay. I bought some of these iCruze surplus displays because I think that are a good gadget for a variety of projects, since they include, among the 20 x 2 line back lit display, a nice cabinet and a good looking bezel. My plan was to remove (or exchange) the pcb with the microprocessor and keep only the display itself and the cabinet, more or less as Bob (fluke.l) did. Anyway I tried to know more about the original circuitry, because it could be useful. Imagine if this is something like a serial ASCII terminal. So I did some reverse engineering, found a signal leaving the device and now I got the schematics. It seems to communicate with I2C, but I'm not sure, it needs some experimentation by someone used to this protocol. Some members of this list already had bought several units and asked me about the information, so I want to know a good place to upload if it can be of interest to mere members, or I can send it directly to the ones that has asked for it. Regards, Ignacio, EB4APL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Self-contained divider board/design available?
At 02:37 PM 3/12/2010, Bert, VE2ZAZ wrote... I warn you, this is a topic that has been discussed before... Just thought I'd mention this, since I haven't seen it here before. The HP 5328a counter has a function where it can act as a (1:10-1:10e7) decade divider. It's in the documentation, but not obvious. One nice thing is that the input is subject to the level and slope controls, which are much more capable than what's found on a simple divider, so you can work with a wider range of input signals. HP: START A, STOP. Sets the counter to totalize the number of events at the A input until STOP is selected, for N=l on the RESOLUTION switch. For Nl, the number of counts divided by N is totalized. The scaled output (i.e., frequency of A/N) is available at the Time Base Out rear panel connector. You can often find them for $100 on eBay, shipping included. Someone with better equipment than I could probably characterize the jitter, etc. ___ 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] 5370B OCXO
Hi I'm looking at things like the plastic shaft pot with switch next to the very similar metal shaft pot with switch on the front panel. Not real likely they were into modern supply practices Bob On Mar 12, 2010, at 3:44 PM, paul swed wrote: Well at least today its a very key reality. Maybe not in the 80s. But I work for a large company that has 10s of thousands of parts and its a very real drive to remove different parts for more commonality. I would bet indeed business drove the position On Fri, Mar 12, 2010 at 12:18 PM, Bob Camp li...@rtty.us wrote: Hi Tough to believe that HP worried a lot about SKU inflation back when they did the 5370 :) I'm assuming that the 5370 was a Santa Clara design. That would put the counter designers down the hall from the oscillator factory. Unlikely that there was a communications gap about what could or could not be done. You may well be correct though. Setting up and managing another part is the most likely reason why not to add a couple more tests. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Friday, March 12, 2010 8:51 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5370B OCXO If I understand this thread correctly. I would speculate it was simply a business choice. 1 less part type to manage. On Fri, Mar 12, 2010 at 7:30 AM, Bob Camp li...@rtty.us wrote: Hi I guess the real question is what a better OCXO would have actually cost. If the 60111 was a test ten, get ten sort of thing (I'm guessing it was) - was a better part simply a test 10 get 9 issue? The claim was made that short term stability testing could be done directly in the aging racks. It's not real clear what the actual cost of an extended test / sort would have been. Bob On Mar 11, 2010, at 10:43 PM, John Miles wrote: Many if not most 5370-based measurements are based on differential timing between the START and STOP channels, and wouldn't benefit from a better 10 MHz reference. If a customer did need something better, they probably already had a house standard to pipe in the back... and if not, HP would have been able to sell them one. It made more sense to keep the cost down by not including a high-end OCXO that would have gone unappreciated by most users. The 5370's jitter+resolution floor doesn't allow it to reach 1E-11 at t=1s in any event, so the -60111 wouldn't have been the limiting factor in the short term. One valid question, though, is why they bothered to put the nicer 10811-60109 OCXOs in the post-2120 series 5065A models, where its short-term performance is hosed by tying it to the rubidium reference with a ~1 Hz loop. Those 5065As would have been OK with a -60111, at least in the pre-2632 serial #s with the original integrator board. I'd be curious to know if they lowered the loop BW when they respun the integrator PCB. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com ]On Behalf Of Bob Camp Sent: Thursday, March 11, 2010 7:11 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 5370B OCXO Hi The OCXO in the 5370B is a 10811-60111. The only added spec on it is a 1x10^-11 ADEV spec at 1 second. By modern standards that's not a real tight spec. There are other 10811's with tighter specs on them at 1 second. My guess is that it was not a real tight spec for the 10811 to hit. The short term would appear to contribute to the total error on the counter. Why not put a better oscillator in 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. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow
Re: [time-nuts] 5370B OXCO
Hi The real question is not how good the best were, but how bad the worst were. If the majority of the population was at 10X where yours is or better, selection would be pretty cheap. Bob On Mar 12, 2010, at 2:24 PM, Corby Dawson wrote: Referencing the performance of 10811 variants really does not help make a good evaluation. You need to measure a particular oscillator to see what it really does. I have rack mounted a 10811-60111 that I use as a short term stability reference. This particular one is consistent with: 1 sec 6.14X10-13th 10 sec 3.52X10-13th 100 sec 3.35X10-13th This of course is a selected unit, but after testing MANY of the different variants it is one of a small percentage of excellent ones. Using it as a counter time base would be a waste! Corby Dawson Love Spell Click here to light up your life with a love spell! http://thirdpartyoffers.juno.com/TGL2141/c?cp=NHEBWbJpRL7hhUMxZQOpngAAJ1ABLZFyqoH-WnHH1GJ345whAAYAAADNRwA= ___ 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] Thunderbolt antenna?
Hi That's quite an antenna. 10 lbs and 14 diameter Bob On Mar 11, 2010, at 11:29 PM, Mark Sims wrote: It doesn't get any better than Ebay item 270262189976... I've tested a couple dozen antennas and nothing comes close to what it does... It's big. It's pricey (but FAR less than the $2000+ original cost). It's good. --- I'm looking for a decent outdoor antenna for my Thunderbolt... I need to graduate beyond the puck-antenna in the window sill. _ Hotmail: Trusted email with Microsoft’s powerful SPAM protection. http://clk.atdmt.com/GBL/go/201469226/direct/01/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt antenna?
Looks like a standard choke ring antenna. Bruce Bob Camp wrote: Hi That's quite an antenna. 10 lbs and 14 diameter Bob On Mar 11, 2010, at 11:29 PM, Mark Sims wrote: It doesn't get any better than Ebay item 270262189976... I've tested a couple dozen antennas and nothing comes close to what it does... It's big. It's pricey (but FAR less than the $2000+ original cost). It's good. --- I'm looking for a decent outdoor antenna for my Thunderbolt... I need to graduate beyond the puck-antenna in the window sill. _ Hotmail: Trusted email with Microsoft’s powerful SPAM protection. http://clk.atdmt.com/GBL/go/201469226/direct/01/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Self-contained divider board/design
Mike, This is neat. I do own a 5328A as well. It does not have option 040, but I believe it does not matter for the application you describe. Just tried it and it works as described. Never knew that! Could anyone characterize the jitter performance of the Timebase Output at one Hz on a 5328A? Bert -- Message: 3 Date: Fri, 12 Mar 2010 18:51:47 -0500 From: mi...@flatsurface.com (Mike S) Subject: Re: [time-nuts] Self-contained divider board/design available? To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 20100313000556.d0ea3117...@hamburg.alientech.net Content-Type: text/plain; charset=us-ascii; format=flowed At 02:37 PM 3/12/2010, Bert, VE2ZAZ wrote... I warn you, this is a topic that has been discussed before... Just thought I'd mention this, since I haven't seen it here before. The HP 5328a counter has a function where it can act as a (1:10-1:10e7) decade divider. It's in the documentation, but not obvious. One nice thing is that the input is subject to the level and slope controls, which are much more capable than what's found on a simple divider, so you can work with a wider range of input signals. HP: START A, STOP. Sets the counter to totalize the number of events at the A input until STOP is selected, for N=l on the RESOLUTION switch. For Nl, the number of counts divided by N is totalized. The scaled output (i.e., frequency of A/N) is available at the Time Base Out rear panel connector. You can often find them for $100 on eBay, shipping included. Someone with better equipment than I could probably characterize the jitter, etc. __ Looking for the perfect gift? Give the gift of Flickr! http://www.flickr.com/gift/ ___ 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] 5370B OCXO
Bob Camp wrote: Hi Tough to believe that HP worried a lot about SKU inflation back when they did the 5370 :) I'm assuming that the 5370 was a Santa Clara design. That would put the counter designers down the hall from the oscillator factory. Unlikely that there was a communications gap about what could or could not be done. You may well be correct though. Setting up and managing another part is the most likely reason why not to add a couple more tests. Bob I was at Santa Clara Division in the 1980's. They worried about both the paper work for extra part numbers and the inventory problem. Especially the latter. There was always some manager whose stock options depended on keeping inventory down (this was during the Japanese just in time fad). Also, if you wanted a part number, you had to obtain one from the official keeper of numbers, and she would usually give you a lecture about the perils of wasting numbers. The counter designers were in a different bldg than the oscillator factory, which were at opposite ends of the 55 acre site. More importantly, they reported to different managers. So you shouldn't assume that communication was great. 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] 5370B OCXO
So little has really changed in 30 years even between completely different companies Dilbert strikes again On Fri, Mar 12, 2010 at 9:57 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: Bob Camp wrote: Hi Tough to believe that HP worried a lot about SKU inflation back when they did the 5370 :) I'm assuming that the 5370 was a Santa Clara design. That would put the counter designers down the hall from the oscillator factory. Unlikely that there was a communications gap about what could or could not be done. You may well be correct though. Setting up and managing another part is the most likely reason why not to add a couple more tests. Bob I was at Santa Clara Division in the 1980's. They worried about both the paper work for extra part numbers and the inventory problem. Especially the latter. There was always some manager whose stock options depended on keeping inventory down (this was during the Japanese just in time fad). Also, if you wanted a part number, you had to obtain one from the official keeper of numbers, and she would usually give you a lecture about the perils of wasting numbers. The counter designers were in a different bldg than the oscillator factory, which were at opposite ends of the 55 acre site. More importantly, they reported to different managers. So you shouldn't assume that communication was great. 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. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt antenna?
Mark wrote: It doesn't get any better than Ebay item 270262189976... I've tested a couple dozen antennas and nothing comes close to what it does... It's big. It's pricey (but FAR less than the $2000+ original cost). It's good. On Mark's advice, I got one of these a few months ago. It will acquire satellites from its current indoor position, which my other antennas (Garmin marine antenna, Lucent timing antenna) will not do. (I'll move it outdoors when nice weather arrives for real.) It also gives a tighter pattern in the LH 3b 48-hour survey. At 26 dB, the gain of the LNA may be a little low for a TBolt if you're going to use a long run of coax, but the design and construction of the amp is much better than the ones in the quadrafilar and patch antennas I've opened. I'm in a severe VHF/UHF environment, and the AeroAntenna seems to cope better than run-of-the-mill marine and timing antennas. Best regards, Charles ___ 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] DMTD Systems Papers
Here's a list of papers I have found on DMTD system designs that have some inside details. If you know of others, please add for future reference. Brian - KD4FM Papers on Dual-Mixer Time-Difference systems: Some Aspects of the Theory and Measurement of Frequency Fluctuations in Frequency Standards. Leonard S. Cutler (Hewlett-Packard Co.) (HP) and Campbell L. Searle (Massachusetts Institute of Technology) (MIT). 1966. Concept. Accurate Measurements of Spectra Density of Phase Noise in Devices. F. L. Walls, S. R. Stein. NBS/NIST. Mixer Information. The Measurement of Frequency and Frequency Stability of Precision Oscillators. David W. Allan National Bureau of Standards (NBS), now the National Institute of Standards and Technology (NIST). NBS Technical Note 669. Report on NBS Dual Mixer Time Difference System (DMTD) built for time-domain measurements associated with Phase 1 of GPS. David Allan NBS/NIST. Has complete schematics of unit described. NBSIR 75-827. An NBS Phase Noise Measurement System Built for Frequency Domain measurements.S. R. Stein NIST. NBSIR 76-846. Phase Noise test set for GPS, includes schematics. Picosecond Time Difference Measurement System. D. W. Allan, H. Daams. 1975.29th Annual Symposium Frequency Control. Basic schematics. Extending the Range and Accuracy of Phase Noise Measurements. F. L. Walls, A. J. D. Clements, C. M. Felton, M. A. Lombardi, and M. D. Vanek. NIST. 1988. Phase noise systems, a little about mixer terminations. Environmental Effects in Mixers and Frequency Distribution systems. L. M. Nelson and F. L. Walls NIST. 1992 IEEE Frequency Control Symposium. Cable timing errors and mixer terminations. The Effect of Harmonic Distortion on Phase errors in Frequency Distribution and Synthesis. F. L. Walls, F. G. Ascarrunz. NIST, SpectraDynamics. Power effects on mixers. Design Considerations in State-of-the-art Signal Processing and Phase Noise Measurement systems. F. L. Walls, S. R. Stein, James E. Gray, David J. Glaze, NIST. Isolation amps and mixer terminations. Application Note 283-3 Low Phase Noise Applications of the HP 8662A and 8663A Synthesized Signal Generators. Hewlett-Packard Co.. Goes into Phase Noise designs and has general purpose information. 10514A/B Mixers Operating and Service Manual 02298-3 Jan 1967, 10534A/B Mixers Operating and Service Manual 02396-2 June 1968. Hewlett-Packard Co. (1) Frequently asked questions about phase detectors. Mini-Circuits AN-41-001. (2) Most often asked questions about mixers. (3) Most Often Asked Questions - Phase detectors. (1) Mixer Application Information. (2) Mixers: Part 1. Characteristics and Performance. (3) Mixers: Part 2 Theory and Technology. (4) Mixers as Phase Detectors. Watkins-Johnson Company Tech-notes. Application Note - Double Balance Mixers. Adams-Russell. (1) Phase Noise (2005). (2) Tutorial on the double balanced mixer (2006). (3) Experimental methods for the measurement of phase noise and frequency stability (2007). (4) Short course on stable oscillators (2009). Enrico Rubiola. FEMTO-ST Institute. Optimization of Dual-Mixer Time Difference Multiplier. L. Sojdr, J. Cermak, R. Barillet. Czech Academy of Sciences, BNM-SYRTE Observatoire de Paris. Describes a DMTD system. Dual-Mixer Time-Difference Multiplier. A. Kuna, J. Roztocil. Czech Technical University. Improvements on DMTD system. ___ 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] DMTD Systems Papers
NIST Technical Note 1337: Characterization of Clocks and Oscillators. It's basically a Time-Nuts Textbook that includes some of the papers you mention as well as many others. 1990 - 22MB - 357 pages. http://tf.boulder.nist.gov/general/pdf/868.pdf The NIST Time Frequency Publication Database is a great place to browse for Time-Nuts treasures (no suprise there!). It took me a while to figure out that to browse the list you just submit an empty search. http://www.tf.nist.gov/timefreq/general/publications.htm Ed Brian Kirby wrote: Here's a list of papers I have found on DMTD system designs that have some inside details. If you know of others, please add for future reference. Brian - KD4FM Papers on Dual-Mixer Time-Difference systems: Some Aspects of the Theory and Measurement of Frequency Fluctuations in Frequency Standards. Leonard S. Cutler (Hewlett-Packard Co.) (HP) and Campbell L. Searle (Massachusetts Institute of Technology) (MIT). 1966. Concept. Accurate Measurements of Spectra Density of Phase Noise in Devices. F. L. Walls, S. R. Stein. NBS/NIST. Mixer Information. The Measurement of Frequency and Frequency Stability of Precision Oscillators. David W. Allan National Bureau of Standards (NBS), now the National Institute of Standards and Technology (NIST). NBS Technical Note 669. Report on NBS Dual Mixer Time Difference System (DMTD) built for time-domain measurements associated with Phase 1 of GPS. David Allan NBS/NIST. Has complete schematics of unit described. NBSIR 75-827. An NBS Phase Noise Measurement System Built for Frequency Domain measurements.S. R. Stein NIST. NBSIR 76-846. Phase Noise test set for GPS, includes schematics. Picosecond Time Difference Measurement System. D. W. Allan, H. Daams. 1975.29th Annual Symposium Frequency Control. Basic schematics. Extending the Range and Accuracy of Phase Noise Measurements. F. L. Walls, A. J. D. Clements, C. M. Felton, M. A. Lombardi, and M. D. Vanek. NIST. 1988. Phase noise systems, a little about mixer terminations. Environmental Effects in Mixers and Frequency Distribution systems. L. M. Nelson and F. L. Walls NIST. 1992 IEEE Frequency Control Symposium. Cable timing errors and mixer terminations. The Effect of Harmonic Distortion on Phase errors in Frequency Distribution and Synthesis. F. L. Walls, F. G. Ascarrunz. NIST, SpectraDynamics. Power effects on mixers. Design Considerations in State-of-the-art Signal Processing and Phase Noise Measurement systems. F. L. Walls, S. R. Stein, James E. Gray, David J. Glaze, NIST. Isolation amps and mixer terminations. Application Note 283-3 Low Phase Noise Applications of the HP 8662A and 8663A Synthesized Signal Generators. Hewlett-Packard Co.. Goes into Phase Noise designs and has general purpose information. 10514A/B Mixers Operating and Service Manual 02298-3 Jan 1967, 10534A/B Mixers Operating and Service Manual 02396-2 June 1968. Hewlett-Packard Co. (1) Frequently asked questions about phase detectors. Mini-Circuits AN-41-001. (2) Most often asked questions about mixers. (3) Most Often Asked Questions - Phase detectors. (1) Mixer Application Information. (2) Mixers: Part 1. Characteristics and Performance. (3) Mixers: Part 2 Theory and Technology. (4) Mixers as Phase Detectors. Watkins-Johnson Company Tech-notes. Application Note - Double Balance Mixers. Adams-Russell. (1) Phase Noise (2005). (2) Tutorial on the double balanced mixer (2006). (3) Experimental methods for the measurement of phase noise and frequency stability (2007). (4) Short course on stable oscillators (2009). Enrico Rubiola. FEMTO-ST Institute. Optimization of Dual-Mixer Time Difference Multiplier. L. Sojdr, J. Cermak, R. Barillet. Czech Academy of Sciences, BNM-SYRTE Observatoire de Paris. Describes a DMTD system. Dual-Mixer Time-Difference Multiplier. A. Kuna, J. Roztocil. Czech Technical University. Improvements on DMTD system. ___ 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.
