Re: [time-nuts] Swagelok and metric tubing question
Hi The first thing that comes to mind with copper and stainless is that they are not quite the same thing electrolytically (you make a battery). That can be ok, or pretty bad depending on how wet your environment is. There may be other issues …. Bob > On Nov 11, 2016, at 8:57 PM, cdel...@juno.com wrote: > > Bob, > > That's the cheapest I have been able to find it. > > I'll probably go that route with the expensive version as it's specified > for compression. > > I know the original setup mixes copper and stainless but I have read that > is not recommended??? > > Cheers, > > Corby > > ___ > 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] Swagelok and metric tubing question
Bob, That's the cheapest I have been able to find it. I'll probably go that route with the expensive version as it's specified for compression. I know the original setup mixes copper and stainless but I have read that is not recommended??? Cheers, Corby ___ 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] Swagelok and metric tubing question
Hi https://www.mcmaster.com/#9811T14 https://www.mcmaster.com/#50365K33 First one is a 2 mm wall at $75 a chunk. Second one is 1.5 mm at $33 a chunk. It’s not obvious why one is “compression fitting” and the other is “weld” rated. In any case, I suspect you need the 2X more expensive, done just for compression fitting versionl. If anybody is looking in their junk box, time to take your calipers out and check if that wall thickness is 2.0 mm or 1.5 mm (I guess …). Bob > On Nov 11, 2016, at 12:51 PM, cdel...@juno.com wrote: > > This sound off topic but it's for a Hydrogen Maser modification! > The EFOS2 Maser is running low on Hydrogen and this time rather than > refill the compressed gas bottle I'd like to install a Hydrostik in its > place. > I have obtained all the fittings I need but have hit a snag! > I need a few short pieces of 10mm OD 1 or 2mm wall stainless tubing to > go into the Metric Swagelok fitting. > However all I can find on the net would cost me over $100.00! > Does anybody have a few short lengths (two 3" and two 4" if cut ready to > insert in the fitting) or one 18" piece that I could buy at a reasonable > price??? > > Thanks, > > Corby > > ___ > 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] Swagelok and metric tubing question
Hi Corby Is there a requirement for a specific alloy? I might have some odds and ends lying around Content by Scott Typos by Siri > On Nov 11, 2016, at 12:51 PM, wrote: > > This sound off topic but it's for a Hydrogen Maser modification! > The EFOS2 Maser is running low on Hydrogen and this time rather than > refill the compressed gas bottle I'd like to install a Hydrostik in its > place. > I have obtained all the fittings I need but have hit a snag! > I need a few short pieces of 10mm OD 1 or 2mm wall stainless tubing to > go into the Metric Swagelok fitting. > However all I can find on the net would cost me over $100.00! > Does anybody have a few short lengths (two 3" and two 4" if cut ready to > insert in the fitting) or one 18" piece that I could buy at a reasonable > price??? > > Thanks, > > Corby > > ___ > 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] Nutty time-nuttery with WWVB
Please see http://support.ntp.org/bin/view/Main/SecurityNotice or Google "NTP security" But perhaps you meant to create a local NTP network with no connection to the Internet. In that case, SNTP is sufficient for wall clocks. Bill Hawkins -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Clint Jay Sent: Friday, November 11, 2016 2:15 AM Rolling it yourself like that would allow you to negate the security risks associated with IoT as you'd have control of the security aspects. ___ 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] Need some wisdom from the cesium beam tube gurus out there
Hi Even *with* all the fancy stuff in my Fluke thermometers … they still are only rated for a bit worse than 0.1 C. When I send them in for calibration, the thermometer generally comes back “calibrated fine”. The thermocouple I send in with them often comes back with a note about “you need to buy a real thermocouple …”. On a simple lash up, you would use a thermocouple that is lying around as your cold junction. If you get yours from eBay (like I do) … who knows what you have. Lots of gotcha’s. Bob > On Nov 11, 2016, at 9:16 AM, Scott Stobbe wrote: > > If you want sub degree precision, you will need to make your connections to > dissimilar metals on an isothermal boundary, a terminal block is better > than clips in free air. > > On Fri, Nov 11, 2016 at 8:28 AM, Bob Camp wrote: > >> Hi >> >>> On Nov 11, 2016, at 8:02 AM, jimlux wrote: >>> >>> On 11/10/16 10:28 PM, Mike Millen wrote: It would work as well if you used a pair of regular copper wires to connect the meter to the thermocouple... The junctions created by all the new connections will cancel out. >>> >>> as long as the temperatures are "exactly" the same, >>> (Seebeck coefficient varies with temperature) >>> and the two metals at the junctions are the same, >>> (ditto, but the curves are different for different materials) >>> and the mechanical configuration is the same >>> (current density also affects it) >> >> The gotcha is that few of us weld copper directly to the thermocouple >> leads. The far more >> common approach is to grab clip leads. At least around here, the clips on >> the leads are >> not made of copper. They are some sort of (badly worn) plating over >> (oxidized) base >> material. >> >> I grab a “copper wire” clip lead and hook up to the thermocouple. There >> isn’t a lot of >> delta T in most bench situations. In this case you have a heated gizmo >> warming things up …. >> Who knows what the delta T may be or how small the contact area actually >> is. >> >> Simple answer: Don’t trust the first number you get. Try it a couple of >> times with *different* >> leads. Make sure you do indeed get within a degree or three on each of >> them. Depending on >> how you have your cold junction set up, that may also need the same >> treatment. >> >> Bob >> >> >>> >>> >>> For run of the mill "measure to 1 degree at room temperature" you can >> probably make that assumption. >>> >>> But if you're looking for precision, you need to take this stuff into >> account (that's what "cold junction compensation" is all about.. ) >>> >>> ___ >>> 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] Need some wisdom from the cesium beam tube gurus out there
Hello to the group. I somewhat suspect we have veered way off the track on the thread or the thread changed and I missed it. Typical of me. Useful comments on Tcouples and wires. But with respect to the start of the subject of unmarked CS tubes easily a 5 or more degree range is fine. You can adjust up or down after you are in range for optimum performance or life as a trade off. Granted you may not actually know what the temperature is to 1 degree. But on an unknown tube its a great place to start. As an example Frankenstein runs 10 C hot approx. It resulted in some fumes of C and I beam. When I started Frankenstein it would have been good to know it was a Tcouple and it should have been an obvious guess. I was just reading and matching voltage outputs after the bridge. Regards Paul WB8TSL On Fri, Nov 11, 2016 at 9:16 AM, Scott Stobbe wrote: > If you want sub degree precision, you will need to make your connections to > dissimilar metals on an isothermal boundary, a terminal block is better > than clips in free air. > > On Fri, Nov 11, 2016 at 8:28 AM, Bob Camp wrote: > > > Hi > > > > > On Nov 11, 2016, at 8:02 AM, jimlux wrote: > > > > > > On 11/10/16 10:28 PM, Mike Millen wrote: > > >> It would work as well if you used a pair of regular copper wires to > > >> connect the meter to the thermocouple... > > >> > > >> The junctions created by all the new connections will cancel out. > > >> > > > > > > as long as the temperatures are "exactly" the same, > > > (Seebeck coefficient varies with temperature) > > > and the two metals at the junctions are the same, > > > (ditto, but the curves are different for different materials) > > > and the mechanical configuration is the same > > > (current density also affects it) > > > > The gotcha is that few of us weld copper directly to the thermocouple > > leads. The far more > > common approach is to grab clip leads. At least around here, the clips on > > the leads are > > not made of copper. They are some sort of (badly worn) plating over > > (oxidized) base > > material. > > > > I grab a “copper wire” clip lead and hook up to the thermocouple. There > > isn’t a lot of > > delta T in most bench situations. In this case you have a heated gizmo > > warming things up …. > > Who knows what the delta T may be or how small the contact area actually > > is. > > > > Simple answer: Don’t trust the first number you get. Try it a couple of > > times with *different* > > leads. Make sure you do indeed get within a degree or three on each of > > them. Depending on > > how you have your cold junction set up, that may also need the same > > treatment. > > > > Bob > > > > > > > > > > > > > For run of the mill "measure to 1 degree at room temperature" you can > > probably make that assumption. > > > > > > But if you're looking for precision, you need to take this stuff into > > account (that's what "cold junction compensation" is all about.. ) > > > > > > ___ > > > 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] Swagelok and metric tubing question
This sound off topic but it's for a Hydrogen Maser modification! The EFOS2 Maser is running low on Hydrogen and this time rather than refill the compressed gas bottle I'd like to install a Hydrostik in its place. I have obtained all the fittings I need but have hit a snag! I need a few short pieces of 10mm OD 1 or 2mm wall stainless tubing to go into the Metric Swagelok fitting. However all I can find on the net would cost me over $100.00! Does anybody have a few short lengths (two 3" and two 4" if cut ready to insert in the fitting) or one 18" piece that I could buy at a reasonable price??? Thanks, Corby ___ 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] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd
>The normal RS-232 level shifter chip includes an inverter. (No good reason, >just historical, but with a long history.) >I can't understand the schematic on the part Gary suggested. I'd use >something like this: > https://www.sparkfun.com/products/11189 Hal, Thanks, this had me look closer at the outputs and not all RS232 chip breakout boards shift all signals, it seems to be 4-6 lines at most. I've seen some MAX3232 (RS232 to TTL) converters, but the better ones only shift Rx, Tx, CTS, RTS, VCC and GND. If I read what was suggested here earlier correctly, I need DCD for the PPS signal and Rx, Tx for NMEA. I plan to use this with pfsense/gpsd which lets you choose between rising and falling edge for PPS signal processing. I'll go ahead and order https://www.sparkfun.com/products/11189 as it appears to do all RS232 signals and can handle voltages > 5V. Thank you all again! ___ 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] Need some wisdom from the cesium beam tube gurus out there
If you want sub degree precision, you will need to make your connections to dissimilar metals on an isothermal boundary, a terminal block is better than clips in free air. On Fri, Nov 11, 2016 at 8:28 AM, Bob Camp wrote: > Hi > > > On Nov 11, 2016, at 8:02 AM, jimlux wrote: > > > > On 11/10/16 10:28 PM, Mike Millen wrote: > >> It would work as well if you used a pair of regular copper wires to > >> connect the meter to the thermocouple... > >> > >> The junctions created by all the new connections will cancel out. > >> > > > > as long as the temperatures are "exactly" the same, > > (Seebeck coefficient varies with temperature) > > and the two metals at the junctions are the same, > > (ditto, but the curves are different for different materials) > > and the mechanical configuration is the same > > (current density also affects it) > > The gotcha is that few of us weld copper directly to the thermocouple > leads. The far more > common approach is to grab clip leads. At least around here, the clips on > the leads are > not made of copper. They are some sort of (badly worn) plating over > (oxidized) base > material. > > I grab a “copper wire” clip lead and hook up to the thermocouple. There > isn’t a lot of > delta T in most bench situations. In this case you have a heated gizmo > warming things up …. > Who knows what the delta T may be or how small the contact area actually > is. > > Simple answer: Don’t trust the first number you get. Try it a couple of > times with *different* > leads. Make sure you do indeed get within a degree or three on each of > them. Depending on > how you have your cold junction set up, that may also need the same > treatment. > > Bob > > > > > > > > For run of the mill "measure to 1 degree at room temperature" you can > probably make that assumption. > > > > But if you're looking for precision, you need to take this stuff into > account (that's what "cold junction compensation" is all about.. ) > > > > ___ > > 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] Need some wisdom from the cesium beam tube gurus out there
Hi > On Nov 11, 2016, at 8:02 AM, jimlux wrote: > > On 11/10/16 10:28 PM, Mike Millen wrote: >> It would work as well if you used a pair of regular copper wires to >> connect the meter to the thermocouple... >> >> The junctions created by all the new connections will cancel out. >> > > as long as the temperatures are "exactly" the same, > (Seebeck coefficient varies with temperature) > and the two metals at the junctions are the same, > (ditto, but the curves are different for different materials) > and the mechanical configuration is the same > (current density also affects it) The gotcha is that few of us weld copper directly to the thermocouple leads. The far more common approach is to grab clip leads. At least around here, the clips on the leads are not made of copper. They are some sort of (badly worn) plating over (oxidized) base material. I grab a “copper wire” clip lead and hook up to the thermocouple. There isn’t a lot of delta T in most bench situations. In this case you have a heated gizmo warming things up …. Who knows what the delta T may be or how small the contact area actually is. Simple answer: Don’t trust the first number you get. Try it a couple of times with *different* leads. Make sure you do indeed get within a degree or three on each of them. Depending on how you have your cold junction set up, that may also need the same treatment. Bob > > > For run of the mill "measure to 1 degree at room temperature" you can > probably make that assumption. > > But if you're looking for precision, you need to take this stuff into account > (that's what "cold junction compensation" is all about.. ) > > ___ > 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] Need some wisdom from the cesium beam tube gurus out there
On 11/10/16 10:28 PM, Mike Millen wrote: It would work as well if you used a pair of regular copper wires to connect the meter to the thermocouple... The junctions created by all the new connections will cancel out. as long as the temperatures are "exactly" the same, (Seebeck coefficient varies with temperature) and the two metals at the junctions are the same, (ditto, but the curves are different for different materials) and the mechanical configuration is the same (current density also affects it) For run of the mill "measure to 1 degree at room temperature" you can probably make that assumption. But if you're looking for precision, you need to take this stuff into account (that's what "cold junction compensation" is all about.. ) ___ 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] Nutty time-nuttery with WWVB
Well I guess I am lucky to live only 20km from the DCF77 transmitter. I can receive DCF77 with a wet finger. I can even use a DCF77 controlled OCXO as my 10MHz standard. Probably not as good as a GPSDO but should be within 1x10^-10 or even better, well enough for my hamradio applications which is shortwave to UHF. If I ever get to it I will try to measure the frequency error of the DCF77 controlled oscillator over the day. I guess not much difference as I receive groundwave all day. Even at my second home in southern France I have a strong DCF77 signal during the night with an indoor antenna (5cm ferrit rod). Heinz DH2FA Von meinem iPhone gesendet > Am 11.11.2016 um 09:14 schrieb Clint Jay : > > I thought the same at first, but then I thought a little more, it may not > be time nut standards of accuracy but... > > It's possible to buy ESP8266 modules for a couple of pounds, they will run > NTP, if you want to go up market then a Pi Zero. > > Hooked up to a cheap DS1307 module or one of the higher stability ones, > then your choice of display, cheap SPI TFT, retro VFD or Nixies, you could > build an NTP synchronised clock for under £10. > > Rolling it yourself like that would allow you to negate the security risks > associated with IoT as you'd have control of the security aspects. > > On 10 November 2016 at 22:59, Ruslan Nabioullin > wrote: > >>> On 11/10/2016 05:46 PM, Tom Van Baak wrote: >>> >>> To be honest, this is very impractical and backward-thinking. I would suggest instead upgrading to the Internet-of-things paradigm, replacing these time-of-day displays with full computers running NTP and connected to your LAN (Android smartwatches; repurposed old smartphones, tablets, laptops, etc.; and smartclocks >>> >>> Hi Ruslan, >>> >>> Please tell me this comment is humor or maybe just trolling. >>> Or are you actually serious? >>> >> >> I am absolutely serious. >> >> -Ruslan >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> > > > > -- > Clint. > > *No trees were harmed in the sending of this mail. However, a large number > of electrons were greatly inconvenienced.* > ___ > 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] Nutty time-nuttery with WWVB
I thought the same at first, but then I thought a little more, it may not be time nut standards of accuracy but... It's possible to buy ESP8266 modules for a couple of pounds, they will run NTP, if you want to go up market then a Pi Zero. Hooked up to a cheap DS1307 module or one of the higher stability ones, then your choice of display, cheap SPI TFT, retro VFD or Nixies, you could build an NTP synchronised clock for under £10. Rolling it yourself like that would allow you to negate the security risks associated with IoT as you'd have control of the security aspects. On 10 November 2016 at 22:59, Ruslan Nabioullin wrote: > On 11/10/2016 05:46 PM, Tom Van Baak wrote: > >> To be honest, this is very impractical and backward-thinking. >>> I would suggest instead upgrading to the Internet-of-things paradigm, >>> replacing >>> these time-of-day displays with full computers running NTP and connected >>> to your LAN (Android smartwatches; repurposed old smartphones, tablets, >>> laptops, etc.; and smartclocks >>> >> >> Hi Ruslan, >> >> Please tell me this comment is humor or maybe just trolling. >> Or are you actually serious? >> > > I am absolutely serious. > > -Ruslan > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. > -- Clint. *No trees were harmed in the sending of this mail. However, a large number of electrons were greatly inconvenienced.* ___ 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.
