[time-nuts] display on sale
Most of you like to DIY, but this might be of interest to some. http://www.symmetricom.com/lp/gbu/email/time-display-promo-landing-page/?emailid=GBU078_NTD_Promo_ProdPglead_source=Web J.D. ___ 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] Why a 10MHz sinewave output?
Hal Murray wrote: li...@rtty.us said: Thank goodness for that inertia. I can still cable up a 100Kcps sine wave standard to run stuff from long ago. When I run into a box that uses a T1 signal for a clock reference - not so easy in the basement. How much gear is there that uses T1 for a clock input? Is there any interest in a board/chip/whatever that converts 10 MHz to T1? A clean design using a decimal DDS should fit into a small FPGA, maybe a CPLD. There is quite a bit of telecom gear that will take a T1(or E1) as a clock reference. A T1 BITS will provide an all 1's AMI signal which looks like 772 kHz on a scope. ___ 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 Launches CSAC Product for Precise Timing and Sync...
Quoting from a white paper on their site: it uses a tiny hollowed-out silicon cube filled with cesium gas. On 01/18/11 20:17, paul swed wrote: Quick question is this a rb reference. Looked at the symetricom site they never actually say or I missed it. On Tue, Jan 18, 2011 at 2:37 PM,saidj...@aol.com wrote: Here is a link to the press release with more technical details and pictures: _ http://www.eetimes.com/electronics-news/4212176/Chip-scale-atomic-clock-app roaches-performance-of-modules-2_ ( http://www.eetimes.com/electronics-news/4212176/Chip-scale-atomic-clock-approaches-performance-of-modules-2 ) In a message dated 1/18/2011 11:32:33 Pacific Standard Time, bro...@pacific.net writes: Hi Mark: I got the idea that it's a Rubidium clock. Have Fun, Brooke Clarke http://www.PRC68.com Mark Spencer wrote: The long term aging spec is interesting to me, as a cesium physics package is a primary standard wouldn't there be an ultimate limit to the total long term aging ? (I took a quick glance at the full data sheet and didn't see any reference to this.) - Original Message From: Julien Goodwintime-n...@studio442.com.au To: Discussion of precise time and frequency measurementtime-nuts@febo.com Sent: Tue, January 18, 2011 8:04:20 AM Subject: Re: [time-nuts] Symmetricom Launches CSAC Product for Precise Timing and Synchronization On 19/01/11 02:35, Pierpaolo Bernardi wrote: Though this could be of interest... http://www.insidegnss.com/node/2446 The SA.45s reportedly provides ... short-term stability (Allan Deviation) of 2E-10 @ 1 sec, long-term aging of 3E-10/month From the data sheet of the bigger Rubidium micro-clocks: SA.33/35m: 1 Sec stability-3E-11 1 month aging - +/1 1E-10 Neat, but only really of benefit to *really* space/weight/power critical devices. The cesium atoms are “excited,” or heated to a vapor state by a beam generated from a vertical-cavity surface emitting laser (VCSEL) that passes between upper and lower polymide heater/suspension strips. The VCSEL was designed by Sandia Labs, one of Symmetricom’s partners on the CSAC team. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DS-1 from 10MHz
Definitely a basement project. J.D. Bob Camp wrote: Hi A lot depends on weather this is a one off basement project or a commercial endeavor. If it's commercial, there are people who will sell you a packaged part that will do the 10 MHz to T1 conversion. Bob On Jul 4, 2010, at 10:38 PM, Hal Murray wrote: I would like to generate a DS-1 timing reference from 10 MHz, e.g a T-bolt. Thought someone here might be able to suggest a starting point. One approach is a PLL. You will have to divide 1.544 MHz by 193 and 10 MHz by 1250. If you want to use the TAPR Clock-Block, I think you will need something like a divide by 10 between the 10 MHz and the Clock-Block to get the numbers within range. I wonder if you could use a VCXO and fit all the logic in a tiny micro. It would probably need a few external parts to filter the PWM output. Maybe the filtering inside the VCXO would be good enough. Another approach is to use a DDS. Analog Devices makes the whole thing in one package, but the numbers don't work out exactly. How close to you need to be? With a 32 bit (binary) adder, you get 1544000.001158 MHz. With 48 bits you get 1543999.99989825. But you don't have to use a binary adder. You have 1000 Hz and you want 1544000 Hz, so you need to multiply by 1544000 and divide by 1000. That reduces to 193 / 1250. So add 193 each cycle using modulo 1250 addition. Each time it overflows, kick out a pulse. If you want a square wave output, divide by 625 and toggle the output on each overflow. That sort of logic fits well in a FPGA/CPLD. That will give you a clock that's locked to your input clock but with lots of jitter. (up to 1/2 clock off in each direction, so 100 ns peak-to-peak) You can run that through a low pass filter and/or feed the top bits into a sine table and on to a DAC. Note that isn't the standard ROM. You have to make a new table for each modulus and if you are using standard ROMs with binary addressing you will waste up to 1/2 of each ROM. -- 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. ___ 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] DS-1 from 10MHz
All, I would like to generate a DS-1 timing reference from 10 MHz, e.g a T-bolt. Thought someone here might be able to suggest a starting point. Thanks, J.D. ___ 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] DS-1 from 10MHz
Perhaps. The DS-1 signal has a pulse-mask which is not square. And while the all 1s AMI signal looks like 772 kHz, presumably the D4 or ESF frame would require some zero's in the 193d bit position. But your suggestion leads to a possible 2 stage solution. There are CSU/DSUs which accept an external TTL level clock. So perhaps use the tapr board to drive the CSU/DSU and let the CSU/DSU build the DS-1 frame. Thanks, J.D. Poul-Henning Kamp wrote: In message 97416.58969...@web30303.mail.mud.yahoo.com, Stanley Reynolds write s: Couldn't you do the same thing much easier with the ICS525 chip ? Neat and convenient: http://tapr.org/kits_clock-block.html Poul-Henning I have a board that does this, I could send you. See Pictures here: www.n4iqt.com/fts4040/ds1 =A0 www.n4iqt.com/fts4040/ds1/FTSds1001.JPG www.n4iqt.com/fts4040/ds1/FTSds1002.JPG www.n4iqt.com/fts4040/ds1/FTSds1003.JPG Stanley - Original Message From: J.D. Schoedel jdschoe...@verizon.net To: Discussion of precise time and frequency measurement time-n...@febo.co= m Sent: Sun, July 4, 2010 11:57:44 AM Subject: [time-nuts] DS-1 from 10MHz All, =A0 I would like to generate a DS-1 timing reference from 10 MHz, e.g a T-b= olt.=A0 = Thought someone here might be able to suggest a starting point. Thanks, J.D. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nu= ts 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-nu= ts 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 5115A Phase Noise Allen Deviation Test Set on ePay
Do you suppose we should ask if it measures Allan variance or are we restricted to Allen variance? J.D. Matt Osborn wrote: On Tue, 6 Apr 2010 19:58:14 +1200, Steve Rooke sar10...@gmail.com wrote: Time to check under the lounge suite cushions for that spare change :) 230458691424 I really like his 'Floopy Drives'. -- kc0ukk at msosborn dot com ___ 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] FS: Brandywine GPS-4 - Qty: 7 available - Manual pics
Scott, What is the synthesizer output on these? It appears to be factory fixed. How will you handle orders? Thanks, J.D. Scott A Sybert wrote: Hi Everyone, Here are some links to pictures of the GPS' and the manual. I've gotten alot of response from people looking for the manuals and photos. I appologize for not posting links in my original email. Pleass feel free to contact me with any questions or concerns http://www.ne900.net/files/GPS1.jpg https://ex14.myhostedexchange.com/exchweb/bin/redir.asp?URL=http://www.ne900.net/files/GPS1.jpg http://www.ne900.net/files/GPS2.jpg https://ex14.myhostedexchange.com/exchweb/bin/redir.asp?URL=http://www.ne900.net/files/GPS2.jpg http://www.ne900.net/files/GPS3.jpg https://ex14.myhostedexchange.com/exchweb/bin/redir.asp?URL=http://www.ne900.net/files/GPS3.jpg http://www.ne900.net/files/GPS4.jpg https://ex14.myhostedexchange.com/exchweb/bin/redir.asp?URL=http://www.ne900.net/files/GPS4.jpg http://www.ne900.net/files/GPS4_Manual_v2.1.pdf https://ex14.myhostedexchange.com/exchweb/bin/redir.asp?URL=http://www.ne900.net/files/GPS4_Manual_v2.1.pdf Regards, Scott KB1FXY 978-423-9855 From: [EMAIL PROTECTED] on behalf of Scott A Sybert Sent: Fri 6/27/2008 8:56 PM To: time-nuts@febo.com Subject: [time-nuts] FS: Brandywine GPS-4 - Qty: 7 available Hi Everyone, I have a number of Brandywine GPS-4 units available. They are all NOS pulls from a cancelled project. They provide a number of outputs including 1PPS and 10MHZ. If anyone is interested I can email you pictures and a copy of the owners manual. Price is $400 and that includes USPS Priority shipping to anywhere in the US. All units are guaranteed working 100%. I also have outdoor Panasonic marine antenna kits w/ 90ft coax. They have a waterproof TNC connecter on the antenna side and a BNC on the GPS side. These kits are also brand new and the price is $40. I can bundle them with the shipping on the GPS. Thanks, Scott KB1FXY ___ 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.
