Re: [time-nuts] Parts Selection
On Fri, 25 Mar 2011 13:07:32 -0400 Bob Camp li...@rtty.us wrote: Done it in the before Yes. I regularly solder 0.5mm and 0.63mm pitch stuff by hand at work. Done it in the basement / last 2 years - no. No. I take all the stuff i want to solder to work and do it there. Although i have equipment at home that would allow me to get everything soldered with a reasonable confidence, the equipment at work allows me to get it working for sure. And being able to check the solder points under a microscope is a nice thing, before you fry something because of a short that you havent seen. :-) We have a reflow oven at work as well, but we hardly ever use it, as we get better results by hand than with the oven. Set up to do it in the basement Yes, but not well, see above. Ok, i have to relativate here, i'm not well equipped in reference to a professional lab. For a hobbist, i have quite good stuff. Would I buy one Yes Would actually do it in a reasonable amount of time 500 pins? That's probably a day or two for me. Depending on the layout and the exact mix of components. 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] WWVB Measurements
On Sat, 26 Mar 2011 17:48:12 -0700 Hal Murray hmur...@megapathdsl.net wrote: Does anybody have any ideas on how much better you could do with an ADC and DSP? There are many. From simple high-tap filters to sofisticated methods like maximum likelyhood decoders. The field is vast and quite well worked on. The book Digital Transmission Engineering by J.B. Anderson provides a good cover of the basic techniques used today, not only DSP based, but in generall. Although the book would counts for me as light reading, it is a graduate level text. I.e. you need some good grasp of signal theorie and some math to understand what's written. It is nevertheless easy to understand even if you dont get all the math. 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.
[time-nuts] UK - GPS Jamming update
The MoD has informed Ofcom of the following GPS jamming exercise update: Reference: JRS0012 Dates and times: GPS jamming will take place according to the following schedule: 6 Apr 1400-1500Z 8 Apr 0200-0400Z 1000-1100Z 1330-1530Z 2000-2359Z 12 Apr 0800-1000Z 2200-2359Z 13 Apr 1400-1600Z 2100-2200Z 14 Apr 0100-0300Z 0800-0900Z Location: GPS jamming will take place from Loch Ewe (N57° 51.9' W005° 41.1'). __ Cheers, David ___ 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] Rubidium physical package size
On 03/31/2011 02:23 AM, paul swed wrote: Magnus any pictures? Eventually. I have realized what I need to document, so this weekend seems like time I have for it. 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] Upgrading TS2100 from TCXO to OCXO
The offset command in the TS2100 is just a phase stepper in 100ns steps. Usage was originally targeted at compensating for the GPS antenna cable length (~ns/ft). As it turned out, we used it for another purpose as well. The very first models of the 2100 used an external GPS receiver (Trimble Acutime) which had an open collector 1PPS. Because of that, we triggered the phase capture on the falling edge of the input signal. When we migrated the design to support an internal receiver (CM3 IIRC), somebody forgot that and we didn't have an extra inverter available at the right spot. What I ended up doing was some conniptions inside the box where we would still trigger on the falling edge and I would use the different default values of offset as compensation for the pulse width. Unfortunately, as we changed GPS modules (CM3-Ace-AceII), the pulse width changed and I don't think anyone ever went back and fixed it. So, between all the different models, and due to the availability of add-on GPS conversion kits, many of these units ended up with different values of info which corresponded to difference GPS receivers and some phase offsets. I'd say just set it to whatever works. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Watzlavick Sent: Thursday, March 31, 2011 6:24 AM To: Discussion of precise time and frequency measurement Cc: Jason Rabel Subject: Re: [time-nuts] Upgrading TS2100 from TCXO to OCXO I changed the root/eng/timing/offset parameter from -100 to 0 on my unit and let it sit overnight. This morning, it is locked and without a frequency offset. So I wonder why my unit would have had a 100 ns offset programmed into it? I cannot figure out how to get the 0 value to stick though. When I power cycle it, it returns back to -100. I programmed various values into to the info field, restarted the unit, and read the following results for the offset parameter: 0x -5 0x0010 -5 0x0021 -5 0x0022 -5 0x0024 -100 0x0028 -5 This is interesting for a couple of reasons. First, it matches what Jason is seeing in his units with the -5 ns value for offset. However, a different TS2100-IRIG unit I looked had an info value of 0 and its offset was also 0. Maybe the presence of the GPS unit makes it think it needs an extra offset? We know that bit 6 is used for GPS vs. UTC for the NTP time (from the manual). I suspect bits 2 and 5 are for GPS since my unit was delivered that way. I would think at least 2 bits would be for the osc type but which ones? And if Jason's unit came delivered as an OCXO, why aren't any bits set to signify that? Maybe the TCXO/OCXO is one configuration and the Rubidium is another. It someone had a factory configured Rubidium unit, it would be interesting to know if there are any bits that correspond to it. -Bob On 03/30/2011 08:40 PM, Robert Watzlavick wrote: My unit (TCXO/GPS originally) has the root/eng/timing/offset set to -100. A TCXO-IRIG unit that I looked at has an offset value of 0. When I was first bringing up my unit with the OCXO, I was comparing the 10 MHz output against a stabilized Thunderbolt and I noticed the TS2100 EFC voltage seemed to stabilize but there was an offset in the 10 MHz output. The lock LED wasn't turning on either. I got impatient and started poking around and that's when I noticed the offset parameter was set to -100. I changed it to 0 and the lock LED immediately turned on but then the EFC started heading the other direction. I put it back at -100, let it sit for a few hours, and it eventually locked without a frequency offset. I'll set my offset back to 0 and see where it ends up overnight. ___ 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] Bunsen on Google
Why is this a Time-Nuts item? Because Bunsen was the chemist who discovered the elements Caesium and Rubidium. He's honored on Google's search page with today's special logo. He invented the Bunsen cell battery, and merely improved the burner that bears his name and every high school student seems to know, the Bunsen burner. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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 3586A/B/C entirely referenced to 10MHz: A solution II
Fellow Listers, Please read and think a bit about my comments before rushing to the reply button. The comments are meant to be technical. When Burt VE2ZAZ posted his HP 3586A/B/C entirely referenced to 10MHz: A solution, I was drooling with envy to add it to my units. However, after reading what it took to make and program it I was completely deflated. While there are those on the list with extensive educational and technical resources, Burt’s project may be just fine. And for those who can make it, go for it. I made a pros and cons list. Advantages Dis-advantages Small- Will fit inside case SMD Components Low power requirements Needs Programming Inexpensive Program varies for various models Awesome build qualityAlmost comes up with the correct numbers Sometimes the only way to solve a problem is with SMD’s, programmed devices etc. But I suspect that for most of us “solutions” of this type are really impractical. Some posts seem to suggest that everyone can program devices, write code, and can work with SMD’s as easily as getting a hamburger at Micky D’s. It just ain’t so. On my level I have to use the KISS principle. Several alternative methods: The cheap method. Turn the crystals 90 degrees so they are perpendicular to the PC board. Make a simple TL431 temperature regulated circuit (I found it on the web by a google search) with a bit of copper and insulation. A small supplemental adjustable tuning capacitor and/or varicap circuit may be needed. It will probably get one as close as the original programmed mod IMHO. The high priced exact solution. Use a HP 3336 locked to the same external standard one is using for the HP 3586B. Remove the original crystal circuit and inject the exact number one needs and get the exact results without any dithering. I’m blessed to have almost all the test equipment, or its equivalents, mentioned on this list sans a spectrum analyzer and from post’s that I have read I’m way ahead of many of the members. I’ve been very impressed, and have learned a great deal, with the posts on the T’bolts, answers to my posted qurstions, WWVB, and HP oscillator fine tuning tips to name a few. On subjects over, or in many cases way over, my head I just read and delete but others find them both fascinating and useful and that’s just fine. Regards, Perrier ___ 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] GPSDO and Rb Oscillators
List FYI, RDR of Centennial CO has listed Lucent GPSDO and Rb Oscillators on epay for very reasonable prices. I’ve purchased several times from them. Lucent only uses a single 24VDC supply. As advertised, good shipping. Disclaimer: no association etc. Regards, Perrier ___ 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 3586A/B/C entirely referenced to 10MHz: A solution II
Perrier wrote: Turn the crystals 90 degrees so they are perpendicular to the PC board. Make a simple TL431 temperature regulated circuit (I found it on the web by a google search) with a bit of copper and insulation. A small supplemental adjustable tuning capacitor and/or varicap circuit may be needed. It will probably get one as close as the original programmed mod IMHO. I very much doubt that the stability of the existing crystals in a homemade oven would come within two orders of magnitude of a divider referenced to a GPSDO. Not to mention that for the oven to work properly, it would have to hold the crystals significantly above ambient temperature, which would presumably be rather far from their optimum tempco point. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPSDO and Rb Oscillators
Perrier, It helps if you give an ebay reference item number so people can see what you are talking about. BillWB6BNQ Perry Sandeen wrote: List FYI, RDR of Centennial CO has listed Lucent GPSDO and Rb Oscillators on epay for very reasonable prices. Iâve purchased several times from them. Lucent only uses a single 24VDC supply. As advertised, good shipping. Disclaimer: no association etc. Regards, Perrier ___ 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 3586A/B/C entirely referenced to 10MHz: A solution II
Perrier, Your simple idea is a non workable concept. Instead of whining about the complexity, why not contact Bert or Paul Swed and see if one of them would do you a favor and build the item for you. I do not believe the hookup part is that hard to do and if You follow instructions well it should be quite doable. BillWBBNQ Perry Sandeen wrote: Fellow Listers, Please read and think a bit about my comments before rushing to the reply button. The comments are meant to be technical. When Burt VE2ZAZ posted his HP 3586A/B/C entirely referenced to 10MHz: A solution, I was drooling with envy to add it to my units. However, after reading what it took to make and program it I was completely deflated. While there are those on the list with extensive educational and technical resources, Burtâs project may be just fine. And for those who can make it, go for it. I made a pros and cons list. Advantages Dis-advantages Small- Will fit inside case SMD Components Low power requirements Needs Programming Inexpensive Program varies for various models Awesome build qualityAlmost comes up with the correct numbers Sometimes the only way to solve a problem is with SMDâs, programmed devices etc. But I suspect that for most of us âsolutionsâ of this type are really impractical. Some posts seem to suggest that everyone can program devices, write code, and can work with SMDâs as easily as getting a hamburger at Micky Dâs. It just ainât so. On my level I have to use the KISS principle. Several alternative methods: The cheap method. Turn the crystals 90 degrees so they are perpendicular to the PC board. Make a simple TL431 temperature regulated circuit (I found it on the web by a google search) with a bit of copper and insulation. A small supplemental adjustable tuning capacitor and/or varicap circuit may be needed. It will probably get one as close as the original programmed mod IMHO. The high priced exact solution. Use a HP 3336 locked to the same external standard one is using for the HP 3586B. Remove the original crystal circuit and inject the exact number one needs and get the exact results without any dithering. Iâm blessed to have almost all the test equipment, or its equivalents, mentioned on this list sans a spectrum analyzer and from postâs that I have read Iâm way ahead of many of the members. Iâve been very impressed, and have learned a great deal, with the posts on the Tâbolts, answers to my posted qurstions, WWVB, and HP oscillator fine tuning tips to name a few. On subjects over, or in many cases way over, my head I just read and delete but others find them both fascinating and useful and thatâs just fine. Regards, Perrier ___ 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.
