Re: [time-nuts] HP 5065A rubidium lifetime
Corby, What I meant by darkening was that the photocell current and the second harmonic were at half of their minimum value given in the manual. I don't know what happens in the RVFR to cause that. Why would a clear bulb have a low output? Can you refer me to something to read? I haven't found the right words to get Google to reveal any useful links. Several years after I bought the 5065 in 2003, there was not enough second harmonic to maintain control, saturating the integrator. So I followed the cure for cell flooding given in the manual. After 10 days the second harmonic stopped improving at about 10 on the meter. Something appears to be microphonic in the photocell. A sharp tap to the case causes the second harmonic to peg the meter briefly. A Tracor 308 does something similar, but it doesn't have a meter for anything but error - the red Unlocked light comes on briefly. Perhaps my brain is darkening with age . . . Bill Hawkins -Original Message- From: Corby Dawson Sent: Friday, March 19, 2010 4:11 PM To: time-nuts@febo.com Subject: [time-nuts] HP 5065A rubidium lifetime I have been repairing HP 5065A for over 20 years and have never had a failure due to darkening I did have one Efratom unit years ago that the lamp envelope had darkened so much it was unusable. Not sure if the is the darkening referred to? The killer 5065A failures are oven failures that melt the insides, and a bulb that has a very low output. (The bulb envelope is still nice and clear in these cases.) The bulb can be replaced with some Efratom ones with varying results. Also cell flooding can occur after long storage and/or storage in high temperatures. This is easily cured by applying 5VDC thru a 5ohm 10watt resistor to the TED (thermoelectric device) in the receiver for 6 days or so. Corby Dawson Diet Help Cheap Diet Help Tips. Click here. http://thirdpartyoffers.juno.com/TGL2141/c?cp=NQ-DyajjqFQSe1WjsW9ZnAAAJ1ABLZ FyqoH-WnHH1GJ345whAAYAAADNAAAYQAA= ___ 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 5065A rubidium lifetime
I can't say for certain. The heating element is a single layer of formvar coated nichrome wire about #36 gage. To avoid magnetic fields, they wound it bifilar, and shorted the far end of the bifilar wires... forming a hairpin loop. I found a short about 1 inch into the 5 inch winding, and the oven driver transistor was open circuited. The 1 inch that wasn't shorted was surrounding the area of the lamp assembly. I recall that the oven fuse was ok. -Chuck Harris John Miles wrote: What was the root cause of the oven failure in your case? -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Chuck Harris Sent: Friday, March 19, 2010 9:58 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5065A rubidium lifetime When my 5065A had its oven failure, it got so hot that it melted all of the solder joints on the lamp board. I resoldered the joints, rewound the oven winding, and foamed the unit with some spray can urethane (Great Stuff), and had it working again for a couple of years. Then something else failed. I'd sure like to fix it, but Scott McGrath, representing himself as an employee of Harvard University, borrowed my manual more than a year ago, and refuses to return it. Oh well! -Chuck Harris ___ 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 5065A rubidium lifetime
Hi Brian, Thanks, I'll download it. My paper manual was an original I bought from HP for about $300. It had all of the change sheets from the very earliest 5065A's to the very latest. I bought the manual in the late 1980's. I like to mention Scott McGrath's deceit as often as polite conversation allows in the groups he likes to frequent. My hope is he will be a man and return the manual. Barring that, I would like everyone that might have the opportunity to deal with him to know what they are getting themselves into. End of this month, I am going to have a chat with his supervisor at Harvard. Since he used a Harvard email address, and had me mail the manual to his office at Harvard, I see this as a Harvard problem. Hear that Scott? You have until the end of March! -Chuck Harris Brian Kirby wrote: Chuck, I bought a 5065A manual and did a high quality scan of it and placed it at http://www.kennethkuhn.com/hpmuseum/scans/ - its in three parts. Unfortunately all I had was a single page scanner - which meant some schematics have 5 scans for each page - but I left overlap so they can be line up and taped together. I used grey scales on the pictures and schematics that needed them Brian KD4FM -Chuck Harris WROTE: I'd sure like to fix it, but Scott McGrath, representing himself as an employee of Harvard University, borrowed my manual more than a year ago, and refuses to return it. Oh well! ___ 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 5065A rubidium lifetime
The bulb on my HP5065A was silver gray in color when I had it out of the oven. It still had plenty of output to make the system work. -Chuck Harris Bill Hawkins wrote: Corby, What I meant by darkening was that the photocell current and the second harmonic were at half of their minimum value given in the manual. I don't know what happens in the RVFR to cause that. Why would a clear bulb have a low output? Can you refer me to something to read? I haven't found the right words to get Google to reveal any useful links. Several years after I bought the 5065 in 2003, there was not enough second harmonic to maintain control, saturating the integrator. So I followed the cure for cell flooding given in the manual. After 10 days the second harmonic stopped improving at about 10 on the meter. Something appears to be microphonic in the photocell. A sharp tap to the case causes the second harmonic to peg the meter briefly. A Tracor 308 does something similar, but it doesn't have a meter for anything but error - the red Unlocked light comes on briefly. Perhaps my brain is darkening with age . . . Bill Hawkins ___ 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] Wavecrest vs. HP 5370 vs. SR620 Jitter measurements
Demian Martin wrote: At some point I'll re-run tempco and jitter measurements of the dividers and 1PPS distribution amps I have here. Last time I used a 5370B and a SR620. This time I'd like to try a Wavecrest. If someone on the list has done this already can you let me know? Thanks, /tvb I have read through the data sheets on all of these and am very interested in the differences in reality. The Wavecrest claims 2 pS Jitter measurement. The HP has a single shot resolution of 20 pS, The SR620 is 25 pS and the Wavecrest specs say 20 pS. How does the Wavecrest get .1X minimum Jitter measurement of the others with the same resolution? Can that trick be applied to the others? The resolution of the DTS-207x series is 800 fs. Getting about 2 ps RMS trigger jitter is achievable with a good source. Slew-rate limits the noise just as with any other trigger jitter. Yes, the Wavecrest blows the SR-620 and HP5370A/B out of the water. The Wavecrests is a bit more resistive to operate, but when you convinced them they do their job well. 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] Schematic and BOM
Tom Van Baak wrote: Hi David, Thanks for the detailed comments. I understand better how the two boards differ now. You did a fine job. And thanks for making it available to the group, with good documentation and all. One comment in the use of microcontrollers -- a reason I (and many others) have used them for timing projects is because they are totally synchronous. All output pins are clocked from the one input clock. In this respect they perform no differently than a synchronous counter. At some point I'll re-run tempco and jitter measurements of the dividers and 1PPS distribution amps I have here. Last time I used a 5370B and a SR620. This time I'd like to try a Wavecrest. If someone on the list has done this already can you let me know? I have HP5370B, SR-620, DTS-2070, CNT-90... among others what do you need? Should I do some test on my assembled TADD-2 divider? 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] HP 5065A rubidium lifetime
Chuck, How did you get to the bulb? I thought the RVFR was a sealed assembly. Bill Hawkins -Original Message- From: Chuck Harris Sent: Saturday, March 20, 2010 7:52 AM The bulb on my HP5065A was silver gray in color when I had it out of the oven. It still had plenty of output to make the system work. -Chuck Harris Bill Hawkins wrote: Corby, What I meant by darkening was that the photocell current and the second harmonic were at half of their minimum value given in the manual. I don't know what happens in the RVFR to cause that. Why would a clear bulb have a low output? Can you refer me to something to read? I haven't found the right words to get Google to reveal any useful links. Several years after I bought the 5065 in 2003, there was not enough second harmonic to maintain control, saturating the integrator. So I followed the cure for cell flooding given in the manual. After 10 days the second harmonic stopped improving at about 10 on the meter. Something appears to be microphonic in the photocell. A sharp tap to the case causes the second harmonic to peg the meter briefly. A Tracor 308 does something similar, but it doesn't have a meter for anything but error - the red Unlocked light comes on briefly. Perhaps my brain is darkening with age . . . Bill Hawkins ___ 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] Schematic and BOM
Hi Can we all come live at your house and play with your toys? Bob On Mar 20, 2010, at 10:06 AM, Magnus Danielson wrote: Tom Van Baak wrote: Hi David, Thanks for the detailed comments. I understand better how the two boards differ now. You did a fine job. And thanks for making it available to the group, with good documentation and all. One comment in the use of microcontrollers -- a reason I (and many others) have used them for timing projects is because they are totally synchronous. All output pins are clocked from the one input clock. In this respect they perform no differently than a synchronous counter. At some point I'll re-run tempco and jitter measurements of the dividers and 1PPS distribution amps I have here. Last time I used a 5370B and a SR620. This time I'd like to try a Wavecrest. If someone on the list has done this already can you let me know? I have HP5370B, SR-620, DTS-2070, CNT-90... among others what do you need? Should I do some test on my assembled TADD-2 divider? 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. ___ 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 5065A rubidium lifetime
Hi A bit off topic, but here it is anyway. If you pull the bulb from a dead FRK rubidium to replace it, most are indeed black. The replacement bulb is nice and clear. A FRK is not a 5065 and the stuff in the bulbs is likely not exactly the same soup of buffer elements. Bob On Mar 20, 2010, at 4:08 AM, Bill Hawkins wrote: Corby, What I meant by darkening was that the photocell current and the second harmonic were at half of their minimum value given in the manual. I don't know what happens in the RVFR to cause that. Why would a clear bulb have a low output? Can you refer me to something to read? I haven't found the right words to get Google to reveal any useful links. Several years after I bought the 5065 in 2003, there was not enough second harmonic to maintain control, saturating the integrator. So I followed the cure for cell flooding given in the manual. After 10 days the second harmonic stopped improving at about 10 on the meter. Something appears to be microphonic in the photocell. A sharp tap to the case causes the second harmonic to peg the meter briefly. A Tracor 308 does something similar, but it doesn't have a meter for anything but error - the red Unlocked light comes on briefly. Perhaps my brain is darkening with age . . . Bill Hawkins -Original Message- From: Corby Dawson Sent: Friday, March 19, 2010 4:11 PM To: time-nuts@febo.com Subject: [time-nuts] HP 5065A rubidium lifetime I have been repairing HP 5065A for over 20 years and have never had a failure due to darkening I did have one Efratom unit years ago that the lamp envelope had darkened so much it was unusable. Not sure if the is the darkening referred to? The killer 5065A failures are oven failures that melt the insides, and a bulb that has a very low output. (The bulb envelope is still nice and clear in these cases.) The bulb can be replaced with some Efratom ones with varying results. Also cell flooding can occur after long storage and/or storage in high temperatures. This is easily cured by applying 5VDC thru a 5ohm 10watt resistor to the TED (thermoelectric device) in the receiver for 6 days or so. Corby Dawson Diet Help Cheap Diet Help Tips. Click here. http://thirdpartyoffers.juno.com/TGL2141/c?cp=NQ-DyajjqFQSe1WjsW9ZnAAAJ1ABLZ FyqoH-WnHH1GJ345whAAYAAADNAAAYQAA= ___ 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] Schematic and BOM
Bob Camp wrote: Hi Can we all come live at your house and play with your toys? That would cause some troubles with logistics, like places to sleep. ;) Tom has far more toys than me. I might have a few things he doesn't have, but other than that he outperforms me in most fields. So far, only two fellow time-nuts have visited my way too small lab. 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] Schematic and BOM
Hi I have a tent Somehow I suspect that commuting to work on a daily basis just might be a little difficult. Bob On Mar 20, 2010, at 12:07 PM, Magnus Danielson wrote: Bob Camp wrote: Hi Can we all come live at your house and play with your toys? That would cause some troubles with logistics, like places to sleep. ;) Tom has far more toys than me. I might have a few things he doesn't have, but other than that he outperforms me in most fields. So far, only two fellow time-nuts have visited my way too small lab. 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. ___ 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 5065A lamp
Bill, The receiver unit is not sealed. To remove the lamp assy. you remove the two nuts (one inside) and the 3 shields from the central threaded rod that protrudes from the lamp end. Then remove the tiny phillips head screws (3) around the circumference of the lamp assy. Wiggle a bit and pull straight out. If you look thru the honey-combed end you will see the bulb. NOTE! when you reassemble the unit the two nuts must be positioned so that they clamp tightly against the last shield cap! It is the heat sink for the lamp assy! Also as to the bulb appearance. A clear bulb can indeed be bad and a discolored bulb can be good! If enough rubidium gets absorbed into the bulb envelope there won't be enough left for proper operation. Bulb can be clear or discolored if this happens. Also the photo-I indication does not always reflect a bad bulb. The photocell responds to all the light from the bulb, but the operation of the standard only needs a good output at a very specific frequency (7800 angstroms). So if the wideband light output is down but the 7800A is good the photo-I is low but the RX output is still good! Hope this helps. Corby Dawson Weight Loss Program Best Weight Loss Program - Click Here! http://thirdpartyoffers.juno.com/TGL2141/c?cp=5VJ_MdJlsnYYM06M27DSiwAAJ1ABLZFyqoH-WnHH1GJ345whAAYAAADNAAAEUgA= ___ 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 5065A lamp
Dear Corby, Corby Dawson wrote: Bill, The receiver unit is not sealed. To remove the lamp assy. you remove the two nuts (one inside) and the 3 shields from the central threaded rod that protrudes from the lamp end. Then remove the tiny phillips head screws (3) around the circumference of the lamp assy. Wiggle a bit and pull straight out. If you look thru the honey-combed end you will see the bulb. NOTE! when you reassemble the unit the two nuts must be positioned so that they clamp tightly against the last shield cap! It is the heat sink for the lamp assy! Also as to the bulb appearance. A clear bulb can indeed be bad and a discolored bulb can be good! If enough rubidium gets absorbed into the bulb envelope there won't be enough left for proper operation. Bulb can be clear or discolored if this happens. Also the photo-I indication does not always reflect a bad bulb. The photocell responds to all the light from the bulb, but the operation of the standard only needs a good output at a very specific frequency (7800 angstroms). So if the wideband light output is down but the 7800A is good the photo-I is low but the RX output is still good! Good point. It makes perfect sense. Thanks for taking the effort to share your experience. Best Regards, 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] Schematic and BOM
When you run a design on a CPLD (or a FPGA) the design tool optimizes cute things like fanout and timing. You can also have it optimize delay to circuit nodes. That allows you to come up with outputs that have a specific delay relationship. From my experience, specific delay relationship is probably pushing it. The Xilinx tools are really setup for building synchronous logic. They are very good at calculating the max delay from A to B. On the other hand, they are almost useless for the min or typical delays. One complication is that sometimes they ship fast parts marked as a slow grade. That's more likely with mature products. When the fab line is well tuned they don't make any slow chips. About the best you can do is something like: If this chunk of a design is the same as that one then the delays will probably be close. Same includes logic, layout, and routing. They will (probably) track closer if they are in the same chip. Internally, the Xilinx tools don't even calculate the min delays. They do works-by-design rather than checking hold times. You can explain it by saying 0 hold time, but what's really going on is that the min prop times have to cover the hold time and clock skew. Note that prop times and hold times track temperature and voltage so the worst case (fastest) prop time happens when you don't need the worst case hold times. I seem to remember that I checked a data sheet many years ago. It was a typical FF, probably something like an x374. The min clock-to-out was not enough to cover the hold time. I just checked a modern data sheet. They didn't even have any numbers for min clock-to-out. Hold times are ugly. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Wanted HP 5087 parts
Howdy - I would like to find a 10 Mhz to 5 Mhz Divider - HP p/n 05087-60013 - and a 5 Mhz to 10 Mhz Doubler - HP p/n 05087-6011 card. If anyone has either one or both as spares, please contact me off list. Thanks - Dave Powers - KA0KCI ___ 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] Schematic and BOM
Hi I've had pretty good luck with Quartus setting up delay relationships and optimizing for them. You are correct that you do get speed variations from the slow model to the fast model. Getting it all to work out is usually a two step process. Find the delay clusters and then shove the outliers towards the center of the cluster. If you make a big change it's back to the start again. You wind up with 7.3 ns +/- 0.5 one time and next time after a big change it'll be 8.7 ns +/- 0.5 Either way you got them set up to 0.5. I suspect there's a way to automate it, but it's easy enough to do by hand for a couple dozen paths. Generally with something like a divider, you just want to make sure that everything going out is all timed the same to the pins of the chip. I would be very surprised if any of the tools had trouble with that. It's pretty much what they were built to do. Bob On Mar 20, 2010, at 3:35 PM, Hal Murray wrote: When you run a design on a CPLD (or a FPGA) the design tool optimizes cute things like fanout and timing. You can also have it optimize delay to circuit nodes. That allows you to come up with outputs that have a specific delay relationship. From my experience, specific delay relationship is probably pushing it. The Xilinx tools are really setup for building synchronous logic. They are very good at calculating the max delay from A to B. On the other hand, they are almost useless for the min or typical delays. One complication is that sometimes they ship fast parts marked as a slow grade. That's more likely with mature products. When the fab line is well tuned they don't make any slow chips. About the best you can do is something like: If this chunk of a design is the same as that one then the delays will probably be close. Same includes logic, layout, and routing. They will (probably) track closer if they are in the same chip. Internally, the Xilinx tools don't even calculate the min delays. They do works-by-design rather than checking hold times. You can explain it by saying 0 hold time, but what's really going on is that the min prop times have to cover the hold time and clock skew. Note that prop times and hold times track temperature and voltage so the worst case (fastest) prop time happens when you don't need the worst case hold times. I seem to remember that I checked a data sheet many years ago. It was a typical FF, probably something like an x374. The min clock-to-out was not enough to cover the hold time. I just checked a modern data sheet. They didn't even have any numbers for min clock-to-out. Hold times are ugly. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Wanted HP 5087 parts
Try posting on TestEquipTrader on YahooGroups. -John Howdy - I would like to find a 10 Mhz to 5 Mhz Divider - HP p/n 05087-60013 - and a 5 Mhz to 10 Mhz Doubler - HP p/n 05087-6011 card. If anyone has either one or both as spares, please contact me off list. Thanks - Dave Powers - KA0KCI ___ 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] 4 KV Power Supply Recommendations Update
You might want to check the 'Advanced Search' feature and see what they have sold for. You might want to make an offer along those lines. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Friday, March 19, 2010 7:15 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 4 KV Power Supply Recommendations Update Boy that is a nice supply. I see them for $129-160 on ebay. ___ 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] Schematic and BOM
Bob Camp wrote: Hi I've had pretty good luck with Quartus setting up delay relationships and optimizing for them. You are correct that you do get speed variations from the slow model to the fast model. Getting it all to work out is usually a two step process. Find the delay clusters and then shove the outliers towards the center of the cluster. If you make a big change it's back to the start again. You wind up with 7.3 ns +/- 0.5 one time and next time after a big change it'll be 8.7 ns +/- 0.5 Either way you got them set up to 0.5. I suspect there's a way to automate it, but it's easy enough to do by hand for a couple dozen paths. Generally with something like a divider, you just want to make sure that everything going out is all timed the same to the pins of the chip. I would be very surprised if any of the tools had trouble with that. It's pretty much what they were built to do. For FPGAs you can make sure that things is clocked at the IO-driver. Removes internal timing except for the timing of the clock distribution. 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] Schematic and BOM
Hi Good point, pretty much everything I worry about is timing to or from an external pin. Once it's inside it's all clocked to the global clock(s). Bob On Mar 20, 2010, at 6:41 PM, Magnus Danielson wrote: Bob Camp wrote: Hi I've had pretty good luck with Quartus setting up delay relationships and optimizing for them. You are correct that you do get speed variations from the slow model to the fast model. Getting it all to work out is usually a two step process. Find the delay clusters and then shove the outliers towards the center of the cluster. If you make a big change it's back to the start again. You wind up with 7.3 ns +/- 0.5 one time and next time after a big change it'll be 8.7 ns +/- 0.5 Either way you got them set up to 0.5. I suspect there's a way to automate it, but it's easy enough to do by hand for a couple dozen paths. Generally with something like a divider, you just want to make sure that everything going out is all timed the same to the pins of the chip. I would be very surprised if any of the tools had trouble with that. It's pretty much what they were built to do. For FPGAs you can make sure that things is clocked at the IO-driver. Removes internal timing except for the timing of the clock distribution. 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. ___ 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 5065A rubidium lifetime
It isn't sealed. The end caps of the oven have several screws. Under the covers are a couple of pieces of foam insulation, and under the insulation are a bunch of aluminum turnings that disassemble with screws. Not a big deal. The lamp comes out one side, and the photocell/microwave stuff come out the other. The filter cells come out of the lamp side, as I recall. -Chuck Harris Bill Hawkins wrote: Chuck, How did you get to the bulb? I thought the RVFR was a sealed assembly. Bill Hawkins ___ 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] HP 5371/2 error
Hi Exactly what does the error message: Error 160 out of sensitivity cal really mean? There seem to be a lot of boxes out there that have this message pop up. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5065A rubidium lifetime
Do you make a 'twisted pair' and then wind that or just wind two parallel wires around the cylinder? Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Saturday, March 20, 2010 7:59 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5065A rubidium lifetime Hi I think I can answer part of that, though I've never dissected a 5065. To make the heater work right you need the proper resistance / foot heater wire. Cupron is a pretty typical material if you want to solder to it. Nicrome is fine if you are welding to it. THe real trick here is to find somebody with a spool of the right stuff and then beg a few feet from them. Doing a hairpin and then twisting is much harder to do right than winding it tightly and then shorting the end of the pair. The easy way to make the twisted pair is to use an electric drill. Once you wind the stuff, both ends are scrap, but the part in the middle is quite good. You loose an inch on each end and get a few feet (or how ever much) out of the middle. Since the maximum temperature the oven can go over ambient rises as the heater resistance goes down (good old P = E^2/R) you might put a heater on thats a slight bit higher in resistance than the original. that would be a problem when it gets to 0 (or -20) in you basement, but it would take the load off of the rest of the parts. Bob On Mar 20, 2010, at 8:30 PM, J. L. Trantham wrote: Chuck, Can you provide any other information about this repair? How much disassembly of the RVFR, what kind of prep of the lamp casing, how much wire, where did you find the wire, did you 'bend' the wire into a 'hairpin' or did you wind two wires then short one end and feed the power from the other end, what kind of prep for the outside cylinder, what kind of 'jig' to hold everything in place while applying the urethane foam, etc., etc. I have two of these and one arrived dead after which I 'killed' it some more with a total melt down. If this should arise again, a repair guide might be very helpful. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris Sent: Saturday, March 20, 2010 7:35 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5065A rubidium lifetime I can't say for certain. The heating element is a single layer of formvar coated nichrome wire about #36 gage. To avoid magnetic fields, they wound it bifilar, and shorted the far end of the bifilar wires... forming a hairpin loop. I found a short about 1 inch into the 5 inch winding, and the oven driver transistor was open circuited. The 1 inch that wasn't shorted was surrounding the area of the lamp assembly. I recall that the oven fuse was ok. -Chuck Harris John Miles wrote: What was the root cause of the oven failure in your case? -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Chuck Harris Sent: Friday, March 19, 2010 9:58 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5065A rubidium lifetime When my 5065A had its oven failure, it got so hot that it melted all of the solder joints on the lamp board. I resoldered the joints, rewound the oven winding, and foamed the unit with some spray can urethane (Great Stuff), and had it working again for a couple of years. Then something else failed. I'd sure like to fix it, but Scott McGrath, representing himself as an employee of Harvard University, borrowed my manual more than a year ago, and refuses to return it. Oh well! -Chuck Harris ___ 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] HP 5371/2 error
Bob, Easy fix!! Soft keys only. Did need to rig up a battery to keep the chip alive, though. 73 de Norm n3ykf Bob Camp li...@rtty.us wrote: Hi Exactly what does the error message: Error 160 out of sensitivity cal really mean? There seem to be a lot of boxes out there that have this message pop up. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5065A rubidium lifetime
Great thread. Though no one answered a question I had. Would it be smart to add a safety. This sounds like a royal pain to rewind a heater. I also did not realize you could open the whole assembly up. Not that I want to. But when the day comes with nothing to loose in I will go. On Sat, Mar 20, 2010 at 10:15 PM, Bob Camp li...@rtty.us wrote: Hi You make a tightly twisted pair. The ides is to get the magnetic field to cancel out. Bob On Mar 20, 2010, at 9:14 PM, J. L. Trantham wrote: Do you make a 'twisted pair' and then wind that or just wind two parallel wires around the cylinder? Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Saturday, March 20, 2010 7:59 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5065A rubidium lifetime Hi I think I can answer part of that, though I've never dissected a 5065. To make the heater work right you need the proper resistance / foot heater wire. Cupron is a pretty typical material if you want to solder to it. Nicrome is fine if you are welding to it. THe real trick here is to find somebody with a spool of the right stuff and then beg a few feet from them. Doing a hairpin and then twisting is much harder to do right than winding it tightly and then shorting the end of the pair. The easy way to make the twisted pair is to use an electric drill. Once you wind the stuff, both ends are scrap, but the part in the middle is quite good. You loose an inch on each end and get a few feet (or how ever much) out of the middle. Since the maximum temperature the oven can go over ambient rises as the heater resistance goes down (good old P = E^2/R) you might put a heater on thats a slight bit higher in resistance than the original. that would be a problem when it gets to 0 (or -20) in you basement, but it would take the load off of the rest of the parts. Bob On Mar 20, 2010, at 8:30 PM, J. L. Trantham wrote: Chuck, Can you provide any other information about this repair? How much disassembly of the RVFR, what kind of prep of the lamp casing, how much wire, where did you find the wire, did you 'bend' the wire into a 'hairpin' or did you wind two wires then short one end and feed the power from the other end, what kind of prep for the outside cylinder, what kind of 'jig' to hold everything in place while applying the urethane foam, etc., etc. I have two of these and one arrived dead after which I 'killed' it some more with a total melt down. If this should arise again, a repair guide might be very helpful. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris Sent: Saturday, March 20, 2010 7:35 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5065A rubidium lifetime I can't say for certain. The heating element is a single layer of formvar coated nichrome wire about #36 gage. To avoid magnetic fields, they wound it bifilar, and shorted the far end of the bifilar wires... forming a hairpin loop. I found a short about 1 inch into the 5 inch winding, and the oven driver transistor was open circuited. The 1 inch that wasn't shorted was surrounding the area of the lamp assembly. I recall that the oven fuse was ok. -Chuck Harris John Miles wrote: What was the root cause of the oven failure in your case? -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of Chuck Harris Sent: Friday, March 19, 2010 9:58 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP 5065A rubidium lifetime When my 5065A had its oven failure, it got so hot that it melted all of the solder joints on the lamp board. I resoldered the joints, rewound the oven winding, and foamed the unit with some spray can urethane (Great Stuff), and had it working again for a couple of years. Then something else failed. I'd sure like to fix it, but Scott McGrath, representing himself as an employee of Harvard University, borrowed my manual more than a year ago, and refuses to return it. Oh well! -Chuck Harris ___ 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
Re: [time-nuts] HP 5371/2 error
It means the battery is dead. See the list archives. The battery is available from Tadiran / Mouser. John K1AE -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Saturday, March 20, 2010 8:30 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] HP 5371/2 error Hi Exactly what does the error message: Error 160 out of sensitivity cal really mean? There seem to be a lot of boxes out there that have this message pop up. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5065A rubidium lifetime
On 21/03/2010, at 11:58 AM, Bob Camp wrote: To make the heater work right you need the proper resistance / foot heater wire. Cupron is a pretty typical material if you want to solder to it. Nicrome is fine if you are welding to it. THe real trick here is to find somebody with a spool of the right stuff and then beg a few feet from them. Hi, Nichrome, stainless steel, iron, nickel, copper, brass in fact most metals other than aluminium, (zinc is messy) solder very easily with a trace of phosphoric acid as a flux. Clean the soldering iron of resin residue, put a trace of phosphoric acid on the wire, and is solders like new copper. The soldering iron and wire are very easily cleaned with water afterwards leaving a tinned nichrome (etc) wire for normal resin cored solder assembly. The phosphoric acid may be of any strength as the water boils out to leave a P2O5 paste on the article. For large items use a huge soldering iron, paint acid on the cold iron/nickel whathave you and it solders very easily. Do not gently heat an iron article with acid on it as within a half minute a protective phosphate coat (like Parkerising) will form to make it impossible to solder. It is worth keeping a tiny bottle of phosphoroic acid just for the odd bit of resistance wire or thermo-couple. You have to see it to believe it. Cheers, Neville Michie ___ 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 5065A rubidium lifetime
Hi Works unless you are in a facility where acid flux is outlawed. Usually not an issue in the basement :). Bob On Mar 20, 2010, at 11:36 PM, Neville Michie wrote: On 21/03/2010, at 11:58 AM, Bob Camp wrote: To make the heater work right you need the proper resistance / foot heater wire. Cupron is a pretty typical material if you want to solder to it. Nicrome is fine if you are welding to it. THe real trick here is to find somebody with a spool of the right stuff and then beg a few feet from them. Hi, Nichrome, stainless steel, iron, nickel, copper, brass in fact most metals other than aluminium, (zinc is messy) solder very easily with a trace of phosphoric acid as a flux. Clean the soldering iron of resin residue, put a trace of phosphoric acid on the wire, and is solders like new copper. The soldering iron and wire are very easily cleaned with water afterwards leaving a tinned nichrome (etc) wire for normal resin cored solder assembly. The phosphoric acid may be of any strength as the water boils out to leave a P2O5 paste on the article. For large items use a huge soldering iron, paint acid on the cold iron/nickel whathave you and it solders very easily. Do not gently heat an iron article with acid on it as within a half minute a protective phosphate coat (like Parkerising) will form to make it impossible to solder. It is worth keeping a tiny bottle of phosphoroic acid just for the odd bit of resistance wire or thermo-couple. You have to see it to believe it. Cheers, Neville Michie ___ 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 5065A rubidium lifetime
HP just wound two parallel wires around the cylinder. They did not twist. The wires at the entrance end of the solenoid went to the electronics, the wires at the exit end of the solenoid were shorted together... I think they used a crimp for the short. -Chuck Harris J. L. Trantham wrote: Do you make a 'twisted pair' and then wind that or just wind two parallel wires around the cylinder? Joe ___ 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.
