Re: [time-nuts] Convert ADEV specs to MDEV?

Hi, On 04/23/2016 02:54 AM, Stewart Cobb wrote: TimeLab can show "mask" overlays on various plots. It comes with a set of ADEV masks for cesium clocks, derived from the manufacturer's specifications for those clocks. Those masks don't show up on MDEV plots, because the manufacturers don't

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

Rather than use the Hat, you might consider just using the breakout board and just using hookup wires to connect it up. Connect up the Vin pin to +5, ground to ground, TX and RX to the serial port pins and the PPS pin to GPIO 18. That’ll save you $5, if nothing else. Add

[time-nuts] Lady Heather coming soon to a Linux box near you...

> This is great news. Will the code be available for inspection / > modification?Yes. It is the same source code as the current version. Just > compile under Linux and voila... The code currently has a no-commerical > copyright on it, but I am going to GPL it (if I can ever figure out what

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

Hi Bob, There's one thing I forgot to mention: the 5 yards of RG-174 that an active puck antenna usually has connected. That's probably a loss of more than 15DB right off the bat. But, if you're using a puck, you're probably using a short cable to your receiver, so you shouldn't cut the

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

Lady Heather does say what the S/N for each satellite is. I use a lot of PA6H modules (the AdaFruit ones) and GPSMon also conveniently gives the S/N too. It’s in the GPGSV sentences. I’m kinda blessed in that my antenna location is just outside the wall from my workbench, and that position

[time-nuts] Convert ADEV specs to MDEV?

TimeLab can show "mask" overlays on various plots. It comes with a set of ADEV masks for cesium clocks, derived from the manufacturer's specifications for those clocks. Those masks don't show up on MDEV plots, because the manufacturers don't provide MDEV specs. For the mathematicians out there:

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

I think all RG6 cable has a solid core otherwise the F type connector wouldn't work. I almost universally use an RG6 type cable for all my receive only systems. In fact, I came across several hundred feet of a Belden product labled 1694A HD-SDI Precision Video Cable 4.5GHz. This has a solid

[time-nuts] Efratom MFS-176 Questions

Hi All, I recently acquired an Erfatom (Datum) MFS-176 RVFS and GPS frequency and time system. The system works, except the date shows September 9, 1996 (increases daily). I can set the date and time during startup, but the displayed date reverts to 1996 when the GPS system locks and is

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

Hi Ok, well, let’s over think this a bit more: The antenna has 38 db gain. It *might* have a noise figure of 0.7 db. A typical modern GPS has < 2db noise figure. Anything over 6 db of net gain is “good enough”. On that basis, a line loss of 32 db would be OK. Your 100 M of quad shield at 21 db

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

One simple trick I have used many times is to split the TX pin from the GPS receiver - ntpd really only needs to receive. Some ntpd refclock drivers will attempt to configure the receiver but if you can ensure that ntpd is getting the messages it needs, then all should be fine. Otherwise, hack the

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

> Again the problem with LH is that it and NTP both want access to the > GPS' serial port. This came up a few months ago. Search in the archives for tboltd, gpsclientd, and wa5znu. Someone wrote a driver to act as a pass through so the Thunderbolt could be connected to Lady Heather, and the

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

Bob, Fair enough. I’ll just stop worrying about it. =) I believe that number sounds like per 100 meter, not per 100 foot. Once I have the actual coax, as someone suggested, I’ll just hook some ends up, and check it. =) Sadly, I don’t have an SA, so checking the attenuation might be

Re: [time-nuts] suitable statistics for measurements with gaps

On 4/22/16 12:41 PM, Hal Murray wrote: jim...@earthlink.net said: But what about when the observations have gaps? Say you're measuring the frequency of a spacecraft oscillator, and you can only see it for 8 hours a day? One interesting question... Can you match up the cycles after the gap?

Re: [time-nuts] suitable statistics for measurements with gaps

jim...@earthlink.net said: > But what about when the observations have gaps? Say you're measuring the > frequency of a spacecraft oscillator, and you can only see it for 8 hours a > day? One interesting question... Can you match up the cycles after the gap? Is your clock stable enough or do

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

Hi Ryan, For the few years I've been on time-nuts, I understood the consensus view to be to get a good quality RG-6QS satellite cable. A few of the posts in this thread have made me wonder if the consensus is changing, or if it's just too much trouble to stand up to the crowd. I've got about

[time-nuts] 3M™ Temflex™ Rubber Splicing Tape 2155

Home Depot carries 3M Electrical Tape Products (Rubber, Cotton Friction, Vinyl) http://www.homedepot.com/b/Electrical-Electrical-Tools-Accessories-Electrical-Tape-Wire-Connectors/3M/N-5yc1vZbm6yZ30 3M Temflex 2155 Rubber Splicing Tape

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

On 21 Apr 2016 01:00, "Bob Camp" wrote: > > Hi > > RG-6 Quad Shield should be fine as long as it’s meeting the published specs. The advantage of LRM-400 is that you likely *know* where it came from and what the specs are. There is plenty of coax marked LMR400 that is produced in

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt)

Paul, LOL! So, along those lines… one other question, since I can’t find my belden, I’ll be buying some coax. Anyone have any opinions about RG6 for CCTV vs CATV? My understanding is the CCTV version always has a solid copper center conductor (which in my mind would mean less voltage loss for

Re: [time-nuts] woodpecker sounds

On Fri, 22 Apr 2016 05:41:25 -0700 jimlux wrote: > although the analysis not by time-nuts, since their statistical analysis > of drumming rates is not of the kind with which *we* are familiar. This > is no surprise: over the past 3 years, I've been looking at literature

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

This is great news. Will the code be available for inspection / modification? Paul Alfille K1PHA On Thu, Apr 21, 2016 at 1:13 AM, Mark Sims wrote: > Well, Lady Heather finally got off her ample ass and dug into the tao of > X11 and all things Linuxy. The program is

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

albertson.ch...@gmail.com said: > The problem is that I think BOTH NTP and LH will want to communicate with > the T-bolt's serial port. You'd have to figure out way around that. They > both can't have exclusive access. ... gpsd uses shared memory to pass info to ntpd. If Lady Heather is

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

paulsw...@gmail.com said: > As I recall there was work using the Pi 1 to make a ntp server and that > could use a simple gps receiver dedicated to the system. Its installation > was pretty simple. Adafruit sells a GPS HAT. Some soldering required: the 40 pin header comes loose. Uputronics

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom, 58532Aand T-bolt)

On 4/22/2016 12:00 PM, time-nuts-requ...@febo.com wrote: On 4/21/16 6:03 PM, Tom Van Baak wrote: >Paul, > >If possible can you make an audio recording of a woodpecker attack? You know it's a form of 1pPS. >I'd like to add that data set to my list of ADEV plots. > I am sure, like almost all

Re: [time-nuts] woodpecker sounds

On 4/22/16 9:18 AM, Poul-Henning Kamp wrote: In message <7521eb48-ebcd-c037-4dcc-8581ed857...@earthlink.net>, jimlux writes: For many years, physiologists eschewed the use of mathematical models. Uhm, that is not really a fair claim. It stems back to the late 19th century, when

Re: [time-nuts] Adapting my GPSDO to the FE-5680A

> On Apr 22, 2016, at 1:58 AM, GandalfG8--- via time-nuts > wrote: > > Thanks. I’ve taken your suggestion for the sine-to-square converter. > I believe there are two separate commands for tuning the 5680 - one is “ > temporary” and one writes through to the EEPROM. I’ll

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

The install is easy as NTP comes with most Linux distributions. So it would likely already be there and all you do is edit the .conf file Again the problem with LH is that it and NTP both want access to the GPS' serial port. NTP can be configured to NOT require access to the GPS' serial port but

Re: [time-nuts] suitable statistics for measurements with gaps

In message <60f3d927-124c-aeb6-8591-81206616f...@earthlink.net>, jimlux writes: >But what about when the observations have gaps? Say you're measuring the >frequency of a spacecraft oscillator, and you can only see it for 8 >hours a day? That will still allow you to calculate

Re: [time-nuts] woodpecker sounds

In message <7521eb48-ebcd-c037-4dcc-8581ed857...@earthlink.net>, jimlux writes: >For many years, physiologists eschewed the use of mathematical models. Uhm, that is not really a fair claim. The research field of "permanent biomonitoring" is barely five years old in terms of usable

Re: [time-nuts] suitable statistics for measurements with gaps

I would think the major difficulty of the scenario you outline would be the periodicity of the measurements coinciding with whatever environmental differences impact the device under test during the measurement window. If you get to see the oscillator the *same* 8 hours every day, are those

[time-nuts] suitable statistics for measurements with gaps

All woodpecker kidding aside, this brings up an interesting question. For most of the measures we look at: ADEV and related measures, you're looking at statistics collected essentially continuously (e.g. adjacent sample frequency) at various time offsets. But what about when the observations

[time-nuts] woodpecker sounds

Cornell has recordings of thousands of bird sounds.. https://www.allaboutbirds.org/guide/Pileated_Woodpecker/sounds and then, the frequency of woodpecker "drumming" has been the subject of some study https://sora.unm.edu/sites/default/files/journals/condor/v100n02/p0350-p0356.pdf reports,

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

Chris, Quite the good point on the TBolt overkill and power. But the whole reason for LH is to monitor an operating TBolt so a great use for something already sucking power is a NTP server. As I recall there was work using the Pi 1 to make a ntp server and that could use a simple gps receiver

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

Hi Chris/Mark, thanks for the feedback on the Pi 3 horsepower. For stratum 1 NTP the PPS interface from the Thunderbolt would be required... Hopefully Mark can conquer the GPU and sound challenges soon. Best regards Darren On 22 April 2016 at 07:01, Chris Albertson

Re: [time-nuts] Adapting my GPSDO to the FE-5680A

Thanks. I’ve taken your suggestion for the sine-to-square converter. I believe there are two separate commands for tuning the 5680 - one is “ temporary” and one writes through to the EEPROM. I’ll be using the latter, of course. --- I'm surprised nobody else seems to have

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532Aand T-bolt)

Groan... >> If possible can you make an audio recording of a woodpecker attack? > I am sure, like almost all oscillators, it will have 1/f flicker noise. In case some of you aren't familiar with the local fauna: https://en.wikipedia.org/wiki/Colaptes -- These are my opinions. I hate spam.

Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532Aand T-bolt)

Love the sound of them as they use the telephone-pole as target, the phone line ties into the house and the ceiling becomes a speaker element. No recording. Woodpeckers run faster than 1 PPS, around 2 PPS or so I'd guess from memory. I was once asked by a friend, who lives a couple of km

Re: [time-nuts] Lady Heather coming soon to a Linux box near you...

Neither of those two programs require much in the way of CPU power and the Pi 3 is a very powerful computer. The Pi 3 could be doing several additional things all at once. I doubt NTP and LH together would use 10% of the Pi 3's CPU. The problem is that I think BOTH NTP and LH will want to