[time-nuts] 74HCT9046A Max. Operating Frequency
Hi, I'm about to implement a PLL for a 24.576 MHz VCXO using the phase-frequency detector (PC2) of the NXP 74HCT9046A. From the datasheet (www.nxp.com/documents/data_sheet/74HCT9046A.pdf) it is not clear to me what the maximum operating frequency for this phase detector is--from the enable and disable times (page 20 and figure 19) I presume 24.576 MHz is too much. So I probably need to add dividers at the inputs. Can someone advise me on the choice of division ratio? Thanks for your time, Samuel ___ 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] 74HCT9046A Max. Operating Frequency
On Thu, 24 Apr 2014 09:41:44 +0100 (BST) sg sg micpre...@yahoo.de wrote: I'm about to implement a PLL for a 24.576 MHz VCXO using the phase-frequency detector (PC2) of the NXP 74HCT9046A. From the datasheet (www.nxp.com /documents/data_sheet/74HCT9046A.pdf) it is not clear to me what the maximum operating frequency for this phase detector is--from the enable and disable times (page 20 and figure 19) I presume 24.576 MHz is too much. So I probably need to add dividers at the inputs. Can someone advise me on the choice of division ratio? Actually, unless i have missed it, there is no specification of the maximum operation frequency of the phase comparators. I guess they assume that everyone is using it the build in VCO which maxes out somewhere around 25MHz (not guaranteed, see Fig23b) So, 27.6MHz should be probably possible. Try it :-) Alternatively you can go to Linear or Analog Devices and buy one of their PLL's that have a specified upper frequency. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ 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] How to accurately measure an oscillator's temperature.
Chris I am not sure if you want to measure temperature or control a fan. To measure there are many options depending on how much money you want to spend. To control I suggest either a LM 335 or a NTC resistor. I have worked extensively with both and for measuring I have now downsized to a YSI. Used to have a HP XTAL thermometer. Spend a lot of time and money on temperature control on Rb's and OCXO's all part of GPSDO's and have come to the conclusion on OCXO's a combination of thermal Isolation and thermal mass is the best solution and on Rb's fans. Spend a year playing with concepts on the FE5680 with all kind of fans and heat sinks and aluminum shapes till it hit me the answer was right in front of me. In my opinion a fan/heat pipe out of an old laptop is the cheapest and best solution, low cost, low noise, no special assemblies and easy to control. Use an aluminum plate as the interface or use the bottom plate directly and use one of the bottom screws to hold your sensor it is internally directly tied to the spine of the Rb. Wide variety available on ebay under CPU fan. Bert Kehren In a message dated 4/23/2014 10:38:11 P.M. Eastern Daylight Time, albertson.ch...@gmail.com writes: I have both an OCXO and an FE-5680 Rb oscillator and I'd like to track their temperatures. What is the best why to measure? Maybe each has a different best method The OCXO is just a small steel can. Is measuring the steel can temperature the best why to go. Epoxy some kind of sensor to it? The Rb is mounded to a large heat sink and there is a fan. I want to control the fan so as to keep the Rb temperature constant. In both cases I tried using TMP36 three terminal sensors and just got noise. The reported temperature was up and down more than 2C.The fan controller just chases noise. BTW the fan based temperature control is effective. The FE5680 gets very warm in it's box but if I give the 12V fan even 8 volts the heat sink quickly cools. I want to throttle the fan to keep the Rb at constant temperature but the temperature data I'm getting is not very good. The problem I think is that any sensor I have is on the outside of the oscillator and is effected by cooling air What are others doing? What's the best kind of sensor. -- Chris Albertson Redondo Beach, California ___ 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] 74HCT9046A Max. Operating Frequency
Hello Samuel, Well, I just got done designing and building the very same thing. If I recall correctly it is the same as the HC4046 which is 4 MHz. The 9046 VCO will only go up to 20 MHz absolute maximum. So you will need an external oscillator and dividers. BillWB6BNQ sg sg wrote: Hi, I'm about to implement a PLL for a 24.576 MHz VCXO using the phase-frequency detector (PC2) of the NXP 74HCT9046A. From the datasheet (www.nxp.com/documents/data_sheet/74HCT9046A.pdf) it is not clear to me what the maximum operating frequency for this phase detector is--from the enable and disable times (page 20 and figure 19) I presume 24.576 MHz is too much. So I probably need to add dividers at the inputs. Can someone advise me on the choice of division ratio? Thanks for your time, Samuel ___ 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] 74HCT9046A Max. Operating Frequency
My feeling has always been that PC2 is most appropriate for very wide-bandwidth (most of an octave or more) VCO's. I have used it at both audio and in 1-2MHz region with success. For 24.576 MHz VCXO, the fractional change in frequency will be in multiple ppm not octaves, and I would naturally gravitate towards a simple diode DBM. Tim. On Thu, Apr 24, 2014 at 4:41 AM, sg sg micpre...@yahoo.de wrote: Hi, I'm about to implement a PLL for a 24.576 MHz VCXO using the phase-frequency detector (PC2) of the NXP 74HCT9046A. From the datasheet ( www.nxp.com/documents/data_sheet/74HCT9046A.pdf) it is not clear to me what the maximum operating frequency for this phase detector is--from the enable and disable times (page 20 and figure 19) I presume 24.576 MHz is too much. So I probably need to add dividers at the inputs. Can someone advise me on the choice of division ratio? Thanks for your time, Samuel ___ 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] Symmetricom chip scale atomic clock
Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock, most common unit is the CSAC GPSDO sold by both symmetricom vendors and direct from Jackson labs Type of issue: Short and Long-term reliability, mfr couldnt assure that if it works for 1week, 1month or 1year it is not an affected unit Issue: CSAC Loss of vacuum, sudden onset failure mode Result: CSAC unable to control the temperature, Indefinite warm-up state, ultimately the unit fails to reach a lock state Failure Rate: Vendor noted ~5% of all units, internally it has been 1 of maybe a dozen or less units to date Resolution Status: Issue acknowledged by manufacturer but not resolved, still affecting all current stock and current production units, Jackson Labs will replace the CSAC part on the board and return without a fee though admittedly the new part may also fail Details: While resolving an issue with a Jackson Labs CSAC GPS Disciplined Oscillator board, we were made aware of a reliability issue affecting all timing boards built around the new Symmetricom Chip Scale Atomic Clocks (a.k.a. CSAC). There is a fundamental design flaw that can result in the loss of vacuum in the CSAC, which prevents the unit from being able to effectively control the parts operating temperature. The end result is a unit that is in an indefinite warm-up state. We were informed that all current and even currently produced units can fail in this way. The number we were given was ~5% of all units will fail, so we happened to get one of those 5%. The failure mode is a very sudden onset failure, for our case one day it worked and the next day (during a test of course) it did not. Also this is not a case of if it works the first week then it will be fine, it can fail anytime (in my case I had used it on a regular basis for several months prior to the failure). Our unit also spent 99% of its life in an air conditioned lab so certainly not subjected to even a remotely harsh environment. Lester B Veenstra MØYCM K1YCM W8YCM les...@veenstras.com US Postal Address: 5 Shrine Club Drive HC84 Box 89C Keyser WV 26726 GPS: 39.336826 N 78.982287 W (Google) GPS: 39.33682 N 78.9823741 W (GPSDO) Telephones: Home: +1-304-289-6057 US cell +1-304-790-9192 UK cell +44-(0)7849-248-749 Guam Cell: +1-671-929-8141 Jamaica: +1-876-456-8898 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. ___ 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] HP Z3805A GPSDO Oven Heater Voltages
Jarl, Thank you for your help on this. It appears that either; the CPU has a bad output pin, some unknown command has turned the heater off, or the firmware is programmed that way. The 10 MHz frequency had always been very 'stable', and I didn't know there was a problem until I bought a 2nd HP Z3805A and felt how warm the (50C) insulated double oven should feel. I am trying to communicate with the seller in Hong Kong. So far he hasn't acknowledged that the CPU output pin can turn-off the heater. By the way, your projects onhttp://risums.net/hjem/oz9mo/index.html http://risums.net/hjem/oz9mo/index.html are very interesting and described very clearly. Nice work! John, KM6QX _ From: Jarl Risum [mailto:jarl.ri...@gmail.com] Sent: Thursday, April 24, 2014 5:23 AM To: John Stuart Subject: Re: HP Z3805A GPSDO Oven Heater Voltages John, Thanks for the feedback and congratulations with your result so far. Unfortunately I have no further information regarding the function of the outer oven control signal from the processor board. You are probably right in assuming that the signal might be used to prevent the outer oven from overheating in case the thermistor went open, since the processor on the main board do monitor the outer oven heater voltage through P2/9. Speculating further: It might also be used by manufacturers to switch off the outer oven heater circuit permanently in HP Z3805's using the 5 MHz MTI OCXO if a suitable RS-232 command exist for this purpose. Cheers from OZ9MO / Jarl in Denmark Some of my Time-Nuttery: http://risums.net/hjem/oz9mo/index.html 2014-04-24 3:13 GMT+02:00 John Stuart j.w.stu...@comcast.net: Jarl, OZ9MO Thank you for those two links! They have the information I needed, and are very well 'hidden' on the internet. I have had partial success. Per the work-around on www.realhamradio.com, I pulled P2-8 on the power board up to +5V, and the outer heater came on and is now being controlled by temperature controller on the power board; TP104 is modulating around 15.75 V. However the heater on/off control signal from the main circuit board (normally connected to P2-8) is still OFF at 0.0 V. For some reason (maybe firmware) the units CPU is not turning on this signal. I am thinking about permanently wiring +5V to P2-8 to keep the heater enabled. Why would the outer oven ever be turned OFF ?? Maybe to prevent over-temperature damage if the NTC sensor fails? When I bought this HP Z3805A from the Hong Kong seller a couple of years ago, it was advertised as having been upgraded to the features (firmware?) of the HP(Symmetricam) 58503A. Does anyone else have this 'model' and does the Double Oven XO keep the unit's top very warm, like it should? John Stuart, KM6QX Lafayette, CA _ From: Jarl Risum [mailto:jarl.ri...@gmail.com] Sent: Wednesday, April 23, 2014 2:22 AM To: j.w.stu...@comcast.net Subject: HP Z3805A GPSDO Oven Heater Voltages Hi John You will find a comprehensive description of the outer oven heater circuit here: http://www.ko4bb.com/Manuals/05%29_GPS_Timing/Z3801/Z3801A_Outer_Oven/Web_Pa ge/Z3801A%20Outer%20Oven%20Controller.htm In my HP Z3805A the outer oven circuit is identical to the circuit in HP Z3801. A description of a Z3801A outer oven fault similar to the one you have can be found here: http://www.realhamradio.com/oven-confusion.htm You will also find a suggestion for a simple remedy. Good luck. Cheers from OZ9MO / Jarl in Denmark ___ 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] Wenzel oscillator - L1 value?
I was under the impression it was a relatively low phase noise design... In any case, my 10MHz crystals are parallel-resonant. Are there any alternative oscillator designs you'd suggest I look into? Thanks, Phil. On 24/04/14 02:38, Bob Camp wrote: HI The circuit they show is not very low phase noise, so adding stuff is not going to degrade it much. It will lower Q, but again, it’s not really Q limited over most of the range. The real issue with the circuit is that it has lousy load isolation. Bob On Apr 23, 2014, at 9:06 PM, Tom Knox act...@hotmail.com wrote: Does adding these filter elements lower Q or affect Phase Noise? Thanks; Thomas Knox From: li...@rtty.us Date: Wed, 23 Apr 2014 17:47:26 -0400 To: time-nuts@febo.com Subject: Re: [time-nuts] Wenzel oscillator - L1 value? Hi Roughly (very roughly) speaking, the series combination of C1, C2, C3 and L1 should equal the load capacitance of the crystal. If there is a varicap, it’s likely in series as well. If the crystal is cut for series, then L1 resonates with the caps in series. You can put it on a Spice program and get more accurate results. Bob On Apr 23, 2014, at 10:23 AM, li...@philpem.me.uk wrote: Hi, I'm currently playing around with crystal oscillators (specifically a homebrew OCXO) and came across the Wenzel low-distortion crystal oscillator: http://www.wenzel.com/pdffiles1/pdfs/xtalosc.pdf This uses an inductor (L1) to trim the crystal frequency, with the note that a varactor/varicap could be added to allow the frequency to be trimmed electronically. Has anyone built one of these oscillators? How would you pick a value for L1? I've been reading up on other crystal oscillator types (Colpitts, Clapp,...) and have yet to find anything which uses this style of frequency trimming. Where would I add the varactor if I wanted to add EFC? Across C3? Thanks. -- Phil. phil...@philpem.me.uk http://www.philpem.me.uk/ ___ 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. -- Phil. li...@philpem.me.uk http://www.philpem.me.uk/ ___ 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] Symmetricom chip scale atomic clock
Hello everyone, let me address the below claims and commentary which was posted without first consulting with us. Microsemi has recently seen a slightly higher failure rate of the CSAC oscillators than expected. A small percentage of our customers have been adversely affected by this issue. We have been, and will continue to take care of this issue when it happens to units we sold by doing a warranty exchange of the CSAC for the affected customer unit, even if it should fall out of its normal warranty period. We believe in supporting our customers to the maximum extent possible, and of course want to deliver a product that has the highest level of quality possible. That said, we must remember that the CSAC technology is a ground breaking, never-before-done in commercial quantities, absolutely new type of oscillator technology, and being at the forefront of such a technology sometimes means there is a bit of a learning curve to deal with. This is one of the main reasons why no one else in the world besides Microsemi makes CSAC type products for commercial sale. So all in all, if a customer unit should get affected by this problem then the issue will be addressed by us and Microsemi with a quick turn around and a no questions asked approach, and we hope that this approach sets us positively apart from the competition. Lastly, we received the below comments/explanation from Microsemi about this issue which we have permission to share with you, and this should help alleviate the problem for new orders. Sincerely, Said Some Symmetricom (now Microsemi) Chip Scale Atomic Clocks have shown a failure mode that will manifest itself as an inability of the clock to achieve atomic lock. If the CSAC’s telemetry string is monitored, the failure mode will show up as a Status Level 8. Microsemi’s investigation into the problem uncovered three distinct root causes, although the symptom the user observes is always a Status Level 8, regardless of which root cause is the underlying issue. It is important to note that all three root causes are process issues, not design issues. All three root causes have been addressed, and Microsemi is currently producing CSAC’s with all three fixes implemented. A full re-qualification of the CSAC is also being done, to ensure that the fixes are effective. CSAC’ s already in the field that exhibit this failure mode have been, and will continue to be, replaced under warranty. In a message dated 4/24/2014 10:16:25 Pacific Daylight Time, les...@veenstras.com writes: Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] D-PSK-R wwvb thread
Back from travel. I hijacked another thread and that is bad behavior. Sorry. So here is the thread all by itself. Background To remove the new wwvb bpsk so that old phase tracking receivers can work. As a by-product of that effort you do obtain the new format data from wwvb. Already released are traditional analog and pseudo digital approaches along with a wwvb RF receiver and regenerators for classic time receivers like the Spectracom 8170 and Truetime DC60. Pretty much all of the approaches so far look for a phase change and invert that change if it departs from the reference. But I have always felt there should be more of a pure digital solution. To add to that the power that is available in the arm evaluation boards is truly amazing along with costs that are very cheap. They include physical boards (No soldering required) and amazing development tools for free. Those combinations are enough to motivate at least me to learn. To date I have experimented a bit with the STM and TI boards in both FORTH and C with help from some fellow Time-Nuts. It has become apparent that the TI launchpad will not be able to hit the speeds needed to do the work. However its simplicity in many respects is helpful in learning about the technology along with great training tools. I am discovering that the STM Discovery board also has pretty good training tools. They are a bit harder to find. However it absolutely has the speed to do some real work and plenty of memory. So the real focus has to be on that board. My challenge to date is with the basics. These processors are very complex in how the utilize all of the IO. Every pin can do numbers of functions like AD, DA, interrupt, timing, clock, and general IO. The clock mechanisms are also very complex with PLL multipliers dividers and such. (Somehow all of the clock stuff has to be very useful) So for the moment I will work through these basics. I can see a solution though. Matthias who reads time-nuts every so often introduced me to some digital techniques on captured wwvb signals that I sent to him that show great promise. Like 30-50 db of tracking gain. You need that on wwvb in the summer. He uses FORTH to program much and I may also. But because of the documentation available for C for both the STM and the Launchpad I will start there to come to terms with all of the base register programming of these chips. Thats at least the start of this thread. Regards Paul WB8TSL ___ 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] Wenzel oscillator - L1 value?
Hi There is no difference at all between a 32 pf series crystal and a 32 pf parallel crystal. They both resonate with a 32 pf load and operate at exactly the same frequency into that load. Your crystals will work fine with that circuit. The big claim to fame of the circuit shown is that you can get a nice looking sine wave out of it at a pretty big peak to peak voltage. It’s not bad for phase noise, but it’s also not the “super quiet” that you would expect if you paid kilo bucks for a Wenzel OCXO. Bob On Apr 24, 2014, at 4:07 PM, Philip Pemberton li...@philpem.me.uk wrote: I was under the impression it was a relatively low phase noise design... In any case, my 10MHz crystals are parallel-resonant. Are there any alternative oscillator designs you'd suggest I look into? Thanks, Phil. On 24/04/14 02:38, Bob Camp wrote: HI The circuit they show is not very low phase noise, so adding stuff is not going to degrade it much. It will lower Q, but again, it’s not really Q limited over most of the range. The real issue with the circuit is that it has lousy load isolation. Bob On Apr 23, 2014, at 9:06 PM, Tom Knox act...@hotmail.com wrote: Does adding these filter elements lower Q or affect Phase Noise? Thanks; Thomas Knox From: li...@rtty.us Date: Wed, 23 Apr 2014 17:47:26 -0400 To: time-nuts@febo.com Subject: Re: [time-nuts] Wenzel oscillator - L1 value? Hi Roughly (very roughly) speaking, the series combination of C1, C2, C3 and L1 should equal the load capacitance of the crystal. If there is a varicap, it’s likely in series as well. If the crystal is cut for series, then L1 resonates with the caps in series. You can put it on a Spice program and get more accurate results. Bob On Apr 23, 2014, at 10:23 AM, li...@philpem.me.uk wrote: Hi, I'm currently playing around with crystal oscillators (specifically a homebrew OCXO) and came across the Wenzel low-distortion crystal oscillator: http://www.wenzel.com/pdffiles1/pdfs/xtalosc.pdf This uses an inductor (L1) to trim the crystal frequency, with the note that a varactor/varicap could be added to allow the frequency to be trimmed electronically. Has anyone built one of these oscillators? How would you pick a value for L1? I've been reading up on other crystal oscillator types (Colpitts, Clapp,...) and have yet to find anything which uses this style of frequency trimming. Where would I add the varactor if I wanted to add EFC? Across C3? Thanks. -- Phil. phil...@philpem.me.uk http://www.philpem.me.uk/ ___ 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. -- Phil. li...@philpem.me.uk http://www.philpem.me.uk/ ___ 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] HP Z3805A GPSDO Oven Heater Voltages
John, I have a similar unit (probably from the same seller), advertised as an Z3805A upgraded to the features of 58503A, whatever that is supposed to mean. Mine also does not get warm on top, though it appears to be providing a decent 10 MHz output and indicates GPS lock. This is the best reference in the lab at the moment so I can't truly speak to the stability of the output. Thanks for the heads-up that the outer oven is not being turned on by the CPU. I haven't opened up the case yet but will do so as soon as my order of round tuits arrives :) Henry On Thu, Apr 24, 2014 at 10:15 AM, John Stuart j.w.stu...@comcast.net wrote: Jarl, Thank you for your help on this. It appears that either; the CPU has a bad output pin, some unknown command has turned the heater off, or the firmware is programmed that way. The 10 MHz frequency had always been very 'stable', and I didn't know there was a problem until I bought a 2nd HP Z3805A and felt how warm the (50C) insulated double oven should feel. I am trying to communicate with the seller in Hong Kong. So far he hasn't acknowledged that the CPU output pin can turn-off the heater. By the way, your projects onhttp://risums.net/hjem/oz9mo/index.html http://risums.net/hjem/oz9mo/index.html are very interesting and described very clearly. Nice work! John, KM6QX _ From: Jarl Risum [mailto:jarl.ri...@gmail.com] Sent: Thursday, April 24, 2014 5:23 AM To: John Stuart Subject: Re: HP Z3805A GPSDO Oven Heater Voltages John, Thanks for the feedback and congratulations with your result so far. Unfortunately I have no further information regarding the function of the outer oven control signal from the processor board. You are probably right in assuming that the signal might be used to prevent the outer oven from overheating in case the thermistor went open, since the processor on the main board do monitor the outer oven heater voltage through P2/9. Speculating further: It might also be used by manufacturers to switch off the outer oven heater circuit permanently in HP Z3805's using the 5 MHz MTI OCXO if a suitable RS-232 command exist for this purpose. Cheers from OZ9MO / Jarl in Denmark Some of my Time-Nuttery: http://risums.net/hjem/oz9mo/index.html 2014-04-24 3:13 GMT+02:00 John Stuart j.w.stu...@comcast.net: Jarl, OZ9MO Thank you for those two links! They have the information I needed, and are very well 'hidden' on the internet. I have had partial success. Per the work-around on www.realhamradio.com, I pulled P2-8 on the power board up to +5V, and the outer heater came on and is now being controlled by temperature controller on the power board; TP104 is modulating around 15.75 V. However the heater on/off control signal from the main circuit board (normally connected to P2-8) is still OFF at 0.0 V. For some reason (maybe firmware) the units CPU is not turning on this signal. I am thinking about permanently wiring +5V to P2-8 to keep the heater enabled. Why would the outer oven ever be turned OFF ?? Maybe to prevent over-temperature damage if the NTC sensor fails? When I bought this HP Z3805A from the Hong Kong seller a couple of years ago, it was advertised as having been upgraded to the features (firmware?) of the HP(Symmetricam) 58503A. Does anyone else have this 'model' and does the Double Oven XO keep the unit's top very warm, like it should? John Stuart, KM6QX Lafayette, CA _ From: Jarl Risum [mailto:jarl.ri...@gmail.com] Sent: Wednesday, April 23, 2014 2:22 AM To: j.w.stu...@comcast.net Subject: HP Z3805A GPSDO Oven Heater Voltages Hi John You will find a comprehensive description of the outer oven heater circuit here: http://www.ko4bb.com/Manuals/05%29_GPS_Timing/Z3801/Z3801A_Outer_Oven/Web_Pa ge/Z3801A%20Outer%20Oven%20Controller.htm In my HP Z3805A the outer oven circuit is identical to the circuit in HP Z3801. A description of a Z3801A outer oven fault similar to the one you have can be found here: http://www.realhamradio.com/oven-confusion.htm You will also find a suggestion for a simple remedy. Good luck. Cheers from OZ9MO / Jarl in Denmark ___ 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] 74HCT9046A Max. Operating Frequency
On 04/24/2014 10:41 AM, sg sg wrote: Hi, I'm about to implement a PLL for a 24.576 MHz VCXO using the phase-frequency detector (PC2) of the NXP 74HCT9046A. From the datasheet (www.nxp.com/documents/data_sheet/74HCT9046A.pdf) it is not clear to me what the maximum operating frequency for this phase detector is--from the enable and disable times (page 20 and figure 19) I presume 24.576 MHz is too much. So I probably need to add dividers at the inputs. Can someone advise me on the choice of division ratio? 24,576 MHz is 128x192 kHz which makes essentially any divide by 2^N chip capable of the frequency a target. Is your reference signal also 24,576 MHz or some other frequency? Cheers, Magnus ___ 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] Symmetricom chip scale atomic clock
Said, I recognize this situation so well. Feel with you on the issue and hope you find that it resolve itself nicely. Cheers, Magnus On 04/24/2014 10:50 PM, saidj...@aol.com wrote: Hello everyone, let me address the below claims and commentary which was posted without first consulting with us. Microsemi has recently seen a slightly higher failure rate of the CSAC oscillators than expected. A small percentage of our customers have been adversely affected by this issue. We have been, and will continue to take care of this issue when it happens to units we sold by doing a warranty exchange of the CSAC for the affected customer unit, even if it should fall out of its normal warranty period. We believe in supporting our customers to the maximum extent possible, and of course want to deliver a product that has the highest level of quality possible. That said, we must remember that the CSAC technology is a ground breaking, never-before-done in commercial quantities, absolutely new type of oscillator technology, and being at the forefront of such a technology sometimes means there is a bit of a learning curve to deal with. This is one of the main reasons why no one else in the world besides Microsemi makes CSAC type products for commercial sale. So all in all, if a customer unit should get affected by this problem then the issue will be addressed by us and Microsemi with a quick turn around and a no questions asked approach, and we hope that this approach sets us positively apart from the competition. Lastly, we received the below comments/explanation from Microsemi about this issue which we have permission to share with you, and this should help alleviate the problem for new orders. Sincerely, Said Some Symmetricom (now Microsemi) Chip Scale Atomic Clocks have shown a failure mode that will manifest itself as an inability of the clock to achieve atomic lock. If the CSAC’s telemetry string is monitored, the failure mode will show up as a Status Level 8. Microsemi’s investigation into the problem uncovered three distinct root causes, although the symptom the user observes is always a Status Level 8, regardless of which root cause is the underlying issue. It is important to note that all three root causes are process issues, not design issues. All three root causes have been addressed, and Microsemi is currently producing CSAC’s with all three fixes implemented. A full re-qualification of the CSAC is also being done, to ensure that the fixes are effective. CSAC’ s already in the field that exhibit this failure mode have been, and will continue to be, replaced under warranty. In a message dated 4/24/2014 10:16:25 Pacific Daylight Time, les...@veenstras.com writes: Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] Symmetricom chip scale atomic clock
Hi I seem to have been in exactly the same position many times before and also wish you well in resolving this (as I’m *certain* will be the case). Bob On Apr 24, 2014, at 7:48 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Said, I recognize this situation so well. Feel with you on the issue and hope you find that it resolve itself nicely. Cheers, Magnus On 04/24/2014 10:50 PM, saidj...@aol.com wrote: Hello everyone, let me address the below claims and commentary which was posted without first consulting with us. Microsemi has recently seen a slightly higher failure rate of the CSAC oscillators than expected. A small percentage of our customers have been adversely affected by this issue. We have been, and will continue to take care of this issue when it happens to units we sold by doing a warranty exchange of the CSAC for the affected customer unit, even if it should fall out of its normal warranty period. We believe in supporting our customers to the maximum extent possible, and of course want to deliver a product that has the highest level of quality possible. That said, we must remember that the CSAC technology is a ground breaking, never-before-done in commercial quantities, absolutely new type of oscillator technology, and being at the forefront of such a technology sometimes means there is a bit of a learning curve to deal with. This is one of the main reasons why no one else in the world besides Microsemi makes CSAC type products for commercial sale. So all in all, if a customer unit should get affected by this problem then the issue will be addressed by us and Microsemi with a quick turn around and a no questions asked approach, and we hope that this approach sets us positively apart from the competition. Lastly, we received the below comments/explanation from Microsemi about this issue which we have permission to share with you, and this should help alleviate the problem for new orders. Sincerely, Said Some Symmetricom (now Microsemi) Chip Scale Atomic Clocks have shown a failure mode that will manifest itself as an inability of the clock to achieve atomic lock. If the CSAC’s telemetry string is monitored, the failure mode will show up as a Status Level 8. Microsemi’s investigation into the problem uncovered three distinct root causes, although the symptom the user observes is always a Status Level 8, regardless of which root cause is the underlying issue. It is important to note that all three root causes are process issues, not design issues. All three root causes have been addressed, and Microsemi is currently producing CSAC’s with all three fixes implemented. A full re-qualification of the CSAC is also being done, to ensure that the fixes are effective. CSAC’ s already in the field that exhibit this failure mode have been, and will continue to be, replaced under warranty. In a message dated 4/24/2014 10:16:25 Pacific Daylight Time, les...@veenstras.com writes: Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] Symmetricom chip scale atomic clock
Hi Magnus, Bob, Thanks much for your kind words. The failure rate is thankfully so low that we are not greatly alarmed, and Microsemi has been a champ in resolving any failures with/for us when they did show up. We are awaiting the results of the full re-qualify that Microsemi is doing on the CSAC and were going to announce the issue at that time.. Bye, Said Sent From iPhone On Apr 24, 2014, at 17:41, Bob Camp li...@rtty.us wrote: Hi I seem to have been in exactly the same position many times before and also wish you well in resolving this (as I’m *certain* will be the case). Bob On Apr 24, 2014, at 7:48 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Said, I recognize this situation so well. Feel with you on the issue and hope you find that it resolve itself nicely. Cheers, Magnus On 04/24/2014 10:50 PM, saidj...@aol.com wrote: Hello everyone, let me address the below claims and commentary which was posted without first consulting with us. Microsemi has recently seen a slightly higher failure rate of the CSAC oscillators than expected. A small percentage of our customers have been adversely affected by this issue. We have been, and will continue to take care of this issue when it happens to units we sold by doing a warranty exchange of the CSAC for the affected customer unit, even if it should fall out of its normal warranty period. We believe in supporting our customers to the maximum extent possible, and of course want to deliver a product that has the highest level of quality possible. That said, we must remember that the CSAC technology is a ground breaking, never-before-done in commercial quantities, absolutely new type of oscillator technology, and being at the forefront of such a technology sometimes means there is a bit of a learning curve to deal with. This is one of the main reasons why no one else in the world besides Microsemi makes CSAC type products for commercial sale. So all in all, if a customer unit should get affected by this problem then the issue will be addressed by us and Microsemi with a quick turn around and a no questions asked approach, and we hope that this approach sets us positively apart from the competition. Lastly, we received the below comments/explanation from Microsemi about this issue which we have permission to share with you, and this should help alleviate the problem for new orders. Sincerely, Said Some Symmetricom (now Microsemi) Chip Scale Atomic Clocks have shown a failure mode that will manifest itself as an inability of the clock to achieve atomic lock. If the CSAC’s telemetry string is monitored, the failure mode will show up as a Status Level 8. Microsemi’s investigation into the problem uncovered three distinct root causes, although the symptom the user observes is always a Status Level 8, regardless of which root cause is the underlying issue. It is important to note that all three root causes are process issues, not design issues. All three root causes have been addressed, and Microsemi is currently producing CSAC’s with all three fixes implemented. A full re-qualification of the CSAC is also being done, to ensure that the fixes are effective. CSAC’ s already in the field that exhibit this failure mode have been, and will continue to be, replaced under warranty. In a message dated 4/24/2014 10:16:25 Pacific Daylight Time, les...@veenstras.com writes: Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] Symmetricom chip scale atomic clock
Out of curiosity, what's the current price for one of these for a time-nut to play with? Regards, Jim Palfreyman On 25 April 2014 11:26, Said Jackson saidj...@aol.com wrote: Hi Magnus, Bob, Thanks much for your kind words. The failure rate is thankfully so low that we are not greatly alarmed, and Microsemi has been a champ in resolving any failures with/for us when they did show up. We are awaiting the results of the full re-qualify that Microsemi is doing on the CSAC and were going to announce the issue at that time.. Bye, Said Sent From iPhone On Apr 24, 2014, at 17:41, Bob Camp li...@rtty.us wrote: Hi I seem to have been in exactly the same position many times before and also wish you well in resolving this (as I’m *certain* will be the case). Bob On Apr 24, 2014, at 7:48 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Said, I recognize this situation so well. Feel with you on the issue and hope you find that it resolve itself nicely. Cheers, Magnus On 04/24/2014 10:50 PM, saidj...@aol.com wrote: Hello everyone, let me address the below claims and commentary which was posted without first consulting with us. Microsemi has recently seen a slightly higher failure rate of the CSAC oscillators than expected. A small percentage of our customers have been adversely affected by this issue. We have been, and will continue to take care of this issue when it happens to units we sold by doing a warranty exchange of the CSAC for the affected customer unit, even if it should fall out of its normal warranty period. We believe in supporting our customers to the maximum extent possible, and of course want to deliver a product that has the highest level of quality possible. That said, we must remember that the CSAC technology is a ground breaking, never-before-done in commercial quantities, absolutely new type of oscillator technology, and being at the forefront of such a technology sometimes means there is a bit of a learning curve to deal with. This is one of the main reasons why no one else in the world besides Microsemi makes CSAC type products for commercial sale. So all in all, if a customer unit should get affected by this problem then the issue will be addressed by us and Microsemi with a quick turn around and a no questions asked approach, and we hope that this approach sets us positively apart from the competition. Lastly, we received the below comments/explanation from Microsemi about this issue which we have permission to share with you, and this should help alleviate the problem for new orders. Sincerely, Said Some Symmetricom (now Microsemi) Chip Scale Atomic Clocks have shown a failure mode that will manifest itself as an inability of the clock to achieve atomic lock. If the CSAC’s telemetry string is monitored, the failure mode will show up as a Status Level 8. Microsemi’s investigation into the problem uncovered three distinct root causes, although the symptom the user observes is always a Status Level 8, regardless of which root cause is the underlying issue. It is important to note that all three root causes are process issues, not design issues. All three root causes have been addressed, and Microsemi is currently producing CSAC’s with all three fixes implemented. A full re-qualification of the CSAC is also being done, to ensure that the fixes are effective. CSAC’ s already in the field that exhibit this failure mode have been, and will continue to be, replaced under warranty. In a message dated 4/24/2014 10:16:25 Pacific Daylight Time, les...@veenstras.com writes: Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] Symmetricom chip scale atomic clock
I believe Microsemi still charges around $1500 for a CSAC. Some were offered on Ebay for around $500 I think some time ago.. Sent From iPhone On Apr 24, 2014, at 18:33, Jim Palfreyman jim77...@gmail.com wrote: Out of curiosity, what's the current price for one of these for a time-nut to play with? Regards, Jim Palfreyman On 25 April 2014 11:26, Said Jackson saidj...@aol.com wrote: Hi Magnus, Bob, Thanks much for your kind words. The failure rate is thankfully so low that we are not greatly alarmed, and Microsemi has been a champ in resolving any failures with/for us when they did show up. We are awaiting the results of the full re-qualify that Microsemi is doing on the CSAC and were going to announce the issue at that time.. Bye, Said Sent From iPhone On Apr 24, 2014, at 17:41, Bob Camp li...@rtty.us wrote: Hi I seem to have been in exactly the same position many times before and also wish you well in resolving this (as I’m *certain* will be the case). Bob On Apr 24, 2014, at 7:48 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Said, I recognize this situation so well. Feel with you on the issue and hope you find that it resolve itself nicely. Cheers, Magnus On 04/24/2014 10:50 PM, saidj...@aol.com wrote: Hello everyone, let me address the below claims and commentary which was posted without first consulting with us. Microsemi has recently seen a slightly higher failure rate of the CSAC oscillators than expected. A small percentage of our customers have been adversely affected by this issue. We have been, and will continue to take care of this issue when it happens to units we sold by doing a warranty exchange of the CSAC for the affected customer unit, even if it should fall out of its normal warranty period. We believe in supporting our customers to the maximum extent possible, and of course want to deliver a product that has the highest level of quality possible. That said, we must remember that the CSAC technology is a ground breaking, never-before-done in commercial quantities, absolutely new type of oscillator technology, and being at the forefront of such a technology sometimes means there is a bit of a learning curve to deal with. This is one of the main reasons why no one else in the world besides Microsemi makes CSAC type products for commercial sale. So all in all, if a customer unit should get affected by this problem then the issue will be addressed by us and Microsemi with a quick turn around and a no questions asked approach, and we hope that this approach sets us positively apart from the competition. Lastly, we received the below comments/explanation from Microsemi about this issue which we have permission to share with you, and this should help alleviate the problem for new orders. Sincerely, Said Some Symmetricom (now Microsemi) Chip Scale Atomic Clocks have shown a failure mode that will manifest itself as an inability of the clock to achieve atomic lock. If the CSAC’s telemetry string is monitored, the failure mode will show up as a Status Level 8. Microsemi’s investigation into the problem uncovered three distinct root causes, although the symptom the user observes is always a Status Level 8, regardless of which root cause is the underlying issue. It is important to note that all three root causes are process issues, not design issues. All three root causes have been addressed, and Microsemi is currently producing CSAC’s with all three fixes implemented. A full re-qualification of the CSAC is also being done, to ensure that the fixes are effective. CSAC’ s already in the field that exhibit this failure mode have been, and will continue to be, replaced under warranty. In a message dated 4/24/2014 10:16:25 Pacific Daylight Time, les...@veenstras.com writes: Affected Products: Jackson Labs or Symmetricom time/frequency reference boards based on Symmetricom chip scale atomic clock ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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
Re: [time-nuts] Symmetricom chip scale atomic clock
On 4/24/14, 6:26 PM, Said Jackson wrote: Hi Magnus, Bob, Thanks much for your kind words. The failure rate is thankfully so low that we are not greatly alarmed, and Microsemi has been a champ in resolving any failures with/for us when they did show up. We are awaiting the results of the full re-qualify that Microsemi is doing on the CSAC and were going to announce the issue at that time.. Sometimes it is the low failure rates which make it so troublesome. Everyone gets excited, but the vast majority don't have the problem, but then, every little anomaly or unexpected event prompts a is it the failure... Good luck.. JIm ___ 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.
