Re: [time-nuts] Spectracom 8140T Line Tap Schematic

2018-06-15 Thread Bob kb8tq
Hi The typical 8140 tap has an ADEV of around 2x10-11 at a tau of 1 second and is in the 3x10^-12 range at 100 seconds. That’s not super duper, but it’s plenty good enough for the intended use of feeding racks full of test gear. If you are feeding it with a typical Cs or telecom Rb, it’s about

[time-nuts] febo.com mailing list reconfiguration completed

2018-06-15 Thread John Ackermann N8UR
The febo.com mailing list system update has completed. Messages to any febo.com list should be sent to @lists.febo.com The web interface is accessible at https://lists.febo.com/mailman/listinfo/ The list archives are accessible at https://lists.febo.com/pipermail/ You may see a security warnin

Re: [time-nuts] ?==?utf-8?q? a newbie question: where can I purchase 794.7nm VCSEL for building CPT rubidium clock?

2018-06-15 Thread Henk Peek
Cheap (CW) lasers such as CD and short distance 850 and 1300nm telecommunication laser have an optical spectrum of a few nm width. This optical spectrum width is filed width multiple optical frequencies. Distributed feedback-lasers generate a single optical frequency. They much more expensiv

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Bob Bownes
Hal, I remember there being such a thing, but a search of the ntp site turns up nothing. Anything you can provide would be most welcome. Thanks! Bob On Fri, Jun 15, 2018 at 12:20 AM, Hal Murray wrote: > > bow...@gmail.com said: > > I’m still hunting for something that will take NTP in and put

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Jerry Hancock
One of the cheapest NTP servers that can be built would be an arduino Uno, CE version for around $10, an LCD display shield with buttons for $15 and an Ethernet shield for $8.95. But getting all that to stack didn’t work, so I had to use jumpers to the LCD part shield. Then add one of the 6 or

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread paul swed
Interesting thread. I guess I would look at things a bit differently. Most of the IRIG clocks have nice displays and perhaps its a case of hacking a device take you pick into those fine displays. I have a really nice 3 RU bright clock that if the brains die thats what I will do. Its a pretty easy t

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread paul swed
By the way I have hacked IRIG B using a proc called SXB and basic language. The specs are out there and its not all that hard. Two tricks that really simplify it. (Everything could be done in software) Use a stable external sine wave 1 KHz oscillator. I used a epson dip oscillator pretty stable. (N

Re: [time-nuts] Raw phase data of super-5065

2018-06-15 Thread Bob kb8tq
Hi I would not find it at all surprising that any of the older Rb’s are running below 1x10^-11 / month these days ( after a good run-in). Below 1x10^-12 is pretty amazing. The FRK’s will normally hang out a bit above that point. Indeed, getting all of the pressure and temperature stuff stable

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Martin VE3OAT
What about the clock part of the old AN/GSQ-53A frequency/time rack? It wasn't NTP of course, but ran off of 1 MHz (as I recall) and generated IRIG-B for remote displays. The rack included a nice Sulzer crystal oscillator (plus a spare), later upgraded to HP rubidium RVFS (5061A?). There mu

Re: [time-nuts] Raw phase data of super-5065

2018-06-15 Thread Tom Van Baak
>From 2002, 5 million samples, 5065A vs. 5071A, drift rate 2e-12 per month: http://www.leapsecond.com/pages/doug-rb/ /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to https://lists.febo.com/cgi-bin/mailman/listinfo/time-

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Bob kb8tq
Hi I suspect part of the answer is “they are cool looking stuff, grab it when it’s swapped out” …. They are out there, but not on the surplus market. Bob > On Jun 15, 2018, at 12:10 PM, Martin VE3OAT wrote: > > What about the clock part of the old AN/GSQ-53A frequency/time rack? > > It wasn'

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread David Andersen
Thanks, all - sounds like either finding a cheap IRIG display or hacking up a pi/arduino/etc. version will be the path forward. The IRIG displays I can find quickly on ebay are still priced for people building music studios, so... RPi 3 B+ supports PoE with an extra hat, and you can get pi-powere

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread paul swed
My reason to hack up a nice clock display is because no matter what I can't make my home brew stuff look as nice. So to me its a pile of displays in a nice rack box that I hook a processor to and do what ever I like. Reversing out the display methods pretty easy as they are typically multiplexed. I

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Bob kb8tq
Hi There are an enormous number of displays out there that will interface with the little boards. You can spend a little or you can spend a *lot*. At least in terms of size, it is a bit of a “you get what you pay for” sort of thing. Some of the larger LED arrays look pretty impressive. Cost w

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Tim Shoppa
At work we have POE LED clocks, I think 2.5", circa $400-$500. So your $300 price you've been seeing is about right. In terms of homebrew: I bought a bunch of 3.5" high green Seven-segment displays 10+ years ago. Cheap, really cheap at the time! Was always intending to build a 6-digit clock with

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Bob Bownes
IRIG-B generator/displays candy had on eBay for very little money. There’s one currently listed for about $10. https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F202337773272 Feeding one of these with the aforementioned NTP to IRIG – B is the easy solution. And th

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread paul swed
That is a great price and the shipping is $12 for a rack mount piece of equipment. How on earth can he do the shipping for that cost? Regards Paul. On Fri, Jun 15, 2018 at 2:51 PM, Bob Bownes wrote: > IRIG-B generator/displays candy had on eBay for very little money. There’s > one currently list

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Hal Murray
bow...@gmail.com said: >> I’m still hunting for something that will take NTP in and put IRIG out. > There is probably someone doing it with a Pi or an Arduino. > I remember there being such a thing, but a search of the ntp site turns up > nothing. Anything you can provide would be most welcome.

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Warren Kumari
A while back I purchased a Symmetricom ND4 clock on eBay -- it was lasted as "Not Working / for parts only", and it turns out that was true -- the processor board had issues. I wasted much time trying to fix it, and then simply removed it -- I'm now using a Raspberry Pi Zero to drive the display pa

Re: [time-nuts] Affordable PoE 6-digit time displays?

2018-06-15 Thread Larry Sampas
For that price (the ND-4), you can get a new NTP-synced PoE-powered clock: http://www.brgprecision.com/products/synchronized_clocks/poeclocks.php I built a time display with a Raspberry Pi, an Adafruit GPS, and a Fundamental Logic USB7 serial LED display, but the numbers didn't flip elegantly or a