[time-nuts] Cs tube links

Hello time-nuts, Well, looks like Word does funny things with copy and pasted links. They all seem to link to picture 9 despite the number in the link. Just correct the number (9 through 12) and they work. Regards, Skip Withrow ___ time-nuts mailing

Re: [time-nuts] Have done some more cutting on the Cs beam tube

Hi Skip, Fantastic 5061 tube photos. Museum quality. Thanks for sharing those with all of us. Four coil wires makes sense, but... 1) The small coil around the beam line looks like the "LF coil"; used only for testing. A brief mention here:

[time-nuts] Have done some more cutting on the Cs beam tube

Hello Time-Nits, Ended up with a little free time and the saw nearby, so did some more cutting on the cesium beam tube today. Links to some pictures are provided for your enjoyment. 1. http://207.224.127.233/CsTube/CsTube9.jpg The first shot shows the new surgery. There is a U shaped

[time-nuts] TICC plots

Here's an hour of Thunderbolt data... with labels for the xDEVs. On narrow screens only the 1-10-100-1000... divisions are labeled and not 1-2-5-10-20... Otherwise the longer labels run together. I also enabled the PPS plot which is basically the PPS jitter. The Star-4 PPS seems to be

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

You are plotting "offset". This is simply the communications path delay. It does not measure your system's deviation from UTC. NTP takes into consideration the offset. Here is the way to understand what NTP does with offset. Let's say we lived 200 years ago and wanted to set a grandfather

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Sorry, I conflated terms. NTP uses offset and delay differently. In NTP speak "delay" is the round trip time. "offset" is the difference from local system clock to reference clock after accounting for delay. It is like cause by asymmetric trans time. But still, I think my main point is

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Hi The point is that some chip sets have better access to timer / counters than others do. One of the Soekris (sp?) boards is an example of this. We also are moving into an era where fairly fancy ARM CPU’s are grafted onto FPGA’s. Once you have that, you are no longer dependent on somebody

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Hi Bob, On Sat, Feb 18, 2017 at 08:36:51AM -0500, Bob Camp wrote: > Hi > > > On Feb 18, 2017, at 4:53 AM, David J Taylor > > wrote: > > > > Hi, > > > > I was wondering whether there is some data/information available on the > > claimed +/- 100 ns jitter? > > > I

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Hi > On Feb 18, 2017, at 4:53 AM, David J Taylor > wrote: > > Hi, > > I was wondering whether there is some data/information available on the > claimed +/- 100 ns jitter? I guess the previous was not complete enough. I routinely measure PPS jitter on GPS

Re: [time-nuts] Installing GPS Antenna

Hi Let’s back off a bit here. If the chimney is above the rest of the house, simply putting the antenna a foot or two above the chimney will get you past the immediate issues of the house blocking or reflecting stuff. If the top of the chimney has a view to the south down to about 10

Re: [time-nuts] Installing GPS Antenna

I pretty much agree on the fittings, only ones designed for outdoor and contact with copper. Stainless steel, bronze etc. I disagree about guy wires, Are you in a area that gets winds and gusts > 30 mph ? Then I would guy it no matter what, it may even be code. Ever get below freezing where you

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

Hi, I was wondering whether there is some data/information available on the claimed +/- 100 ns jitter? Regarding the PPS -> USB (using the CTS line of a FTDI FT232R), I plotted, using some lines of Python, the time offset as attached. Just to get an overview how it is 'worst case', i.e., user

Re: [time-nuts] Installing GPS Antenna

Copper? What an expensive material to use. Galvanized iron pipe is cheaper and very strong. But even the thinner "type M" copper pipe is strong enough if it is 1 1/4" diameter. You should not need guy wires on such a short mast. You will need likely the proper threaded adaptor to fit the