[time-nuts] TBolt OCXO replacement
In the ever ending battle to improve my TBolt's performance, I am in the process of upgrading a OCXO replacement I did to it a while back. It would be Interesting to hear suggestions from others that have done similar sort of things and the results they have achieved. ws ___ 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] TBolt OCXO replacement
At 11:37 AM 2/16/2010 , WarrenS wrote: In the ever ending battle to improve my TBolt's performance, I am in the process of upgrading a OCXO replacement I did to it a while back. It would be Interesting to hear suggestions from others that have done similar sort of things and the results they have achieved. Did you check out John Miles's writeup? http://www.thegleam.com/ke5fx/tbolt.htm ___ 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] Hands on digital clock
Hi: http://www.standard-time.com/index2_en.php 4 x 12 meter 7-segment display where the segments are boards held in place by C-clamps. One man can change one segment, but it takes 11 men and a couple of ladders to change two digits. If fewer (wo)men were used the time to make a change would be longer than 1 minute and the clock not be good to a minute. It looks like they started out using 4 bolts at each joint with power tools and later changed to multiple C-clamps. You can buy a DVD movie that can be played on a PC where the video is synchronized to the PC time. For more interesting On Line Hardware Clocks see: http://www.prc68.com/I/timefreq.shtml#OLC -- Have Fun, Brooke Clarke http://www.PRC68.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.
Re: [time-nuts] Hands on digital clock
It seems to me there is a way to make the segments folding so they could be changed without removing and inserting boards. Kind of like a folding ruler. I'll have to do some experiments with scraps of wood in my shop. On a smaller scale of course. When I was little I used to like forming letters and numbers with my dad's folding ruler. I probably invented the 7 segment display without knowing it. Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Brooke Clarke bro...@pacific.net To: time-nuts@febo.com Sent: Tuesday, February 16, 2010 3:46 PM Subject: [time-nuts] Hands on digital clock Hi: http://www.standard-time.com/index2_en.php 4 x 12 meter 7-segment display where the segments are boards held in place by C-clamps. One man can change one segment, but it takes 11 men and a couple of ladders to change two digits. If fewer (wo)men were used the time to make a change would be longer than 1 minute and the clock not be good to a minute. It looks like they started out using 4 bolts at each joint with power tools and later changed to multiple C-clamps. You can buy a DVD movie that can be played on a PC where the video is synchronized to the PC time. For more interesting On Line Hardware Clocks see: http://www.prc68.com/I/timefreq.shtml#OLC -- Have Fun, Brooke Clarke http://www.PRC68.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. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.435 / Virus Database: 271.1.1/2689 - Release Date: 02/15/10 07:35:00 ___ 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] Hands on digital clock
Hey. You miss the point! It's ART. -John = It seems to me there is a way to make the segments folding so they could be changed without removing and inserting boards. Kind of like a folding ruler. I'll have to do some experiments with scraps of wood in my shop. On a smaller scale of course. When I was little I used to like forming letters and numbers with my dad's folding ruler. I probably invented the 7 segment display without knowing it. Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Brooke Clarke bro...@pacific.net To: time-nuts@febo.com Sent: Tuesday, February 16, 2010 3:46 PM Subject: [time-nuts] Hands on digital clock Hi: http://www.standard-time.com/index2_en.php 4 x 12 meter 7-segment display where the segments are boards held in place by C-clamps. One man can change one segment, but it takes 11 men and a couple of ladders to change two digits. If fewer (wo)men were used the time to make a change would be longer than 1 minute and the clock not be good to a minute. It looks like they started out using 4 bolts at each joint with power tools and later changed to multiple C-clamps. You can buy a DVD movie that can be played on a PC where the video is synchronized to the PC time. For more interesting On Line Hardware Clocks see: http://www.prc68.com/I/timefreq.shtml#OLC -- Have Fun, Brooke Clarke http://www.PRC68.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. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.435 / Virus Database: 271.1.1/2689 - Release Date: 02/15/10 07:35:00 ___ 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] TBolt OCXO replacement
Hi A similar question though would be - once you have done all the corrections to the setup of the TBolt (damping, time constant, sensitivity) what's left to fix? I would *guess*: Lower aging Better TC Better short term Aging will likely get better the longer you leave the existing oscillator on power. You also may be able to pick between units to find the best of 4 or something like that. TC can be improved a number of ways simply by helping the existing part. I think we have gone over that in about 300,000 messages so far. Short term stability is about the only thing I can see that's still on the list. That gets you to the question - just how good do you think the 1 second AVAR is on the existing oscillator, independent of the TBolt environment? If for instance you have a 2.5x10^-12 OCXO in yours, you would only see a significant improvement with a sub 1.0x10^-12 OCXO. That sort of bounds your OCXO shopping list right there. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Scott Newell Sent: Tuesday, February 16, 2010 1:06 PM To: time-nuts@febo.com Subject: Re: [time-nuts] TBolt OCXO replacement At 11:37 AM 2/16/2010 , WarrenS wrote: In the ever ending battle to improve my TBolt's performance, I am in the process of upgrading a OCXO replacement I did to it a while back. It would be Interesting to hear suggestions from others that have done similar sort of things and the results they have achieved. Did you check out John Miles's writeup? http://www.thegleam.com/ke5fx/tbolt.htm ___ 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] TBolt OCXO replacement
Timing newbie here, so please educate me - why does aging matter? Isn't the whole purpose of a GPSDO to completely eliminate long-term drift? Thanks Henry On Tue, Feb 16, 2010 at 2:36 PM, Bob Camp li...@cq.nu wrote: Hi A similar question though would be - once you have done all the corrections to the setup of the TBolt (damping, time constant, sensitivity) what's left to fix? I would *guess*: Lower aging Better TC Better short term Aging will likely get better the longer you leave the existing oscillator on power. You also may be able to pick between units to find the best of 4 or something like that. TC can be improved a number of ways simply by helping the existing part. I think we have gone over that in about 300,000 messages so far. Short term stability is about the only thing I can see that's still on the list. That gets you to the question - just how good do you think the 1 second AVAR is on the existing oscillator, independent of the TBolt environment? If for instance you have a 2.5x10^-12 OCXO in yours, you would only see a significant improvement with a sub 1.0x10^-12 OCXO. That sort of bounds your OCXO shopping list right there. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Scott Newell Sent: Tuesday, February 16, 2010 1:06 PM To: time-nuts@febo.com Subject: Re: [time-nuts] TBolt OCXO replacement At 11:37 AM 2/16/2010 , WarrenS wrote: In the ever ending battle to improve my TBolt's performance, I am in the process of upgrading a OCXO replacement I did to it a while back. It would be Interesting to hear suggestions from others that have done similar sort of things and the results they have achieved. Did you check out John Miles's writeup? http://www.thegleam.com/ke5fx/tbolt.htm ___ 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. -- Henry Hallam Sent from my Laptop ___ 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] ko4bb monitor
Thunderbolt PRECISION GPS 10mhz Standard's LED Monitor I received two from fluke.l 16 days after I sent my PayPal payment. It was well-packaged and he fit both in one box to save me shipping costs. They came with a DB-9P already soldered on the cable and a typical DC power jack. He even included shells for the DB-9P. They both powered up fine and started talking with my Thunderbolts right away. Current drain is about 75 ma at start-up and then falls to 50 ma (13.6 volts). It's not Lady Heather, but I can monitor my TBolts at a glance without tying up PCs. Mike - AA8K Arthur Dent wrote: The display I got from fluke.l (ordered 12-4-09) ran on +5V but the one I got from Amazon had a 3-terminal regulator and would run from 7-20V and was designed for +12V. I just noticed Bob's Ebay listing has been changed to add this note: because of some reasons,i change one IC on the PCB, so the buyer whom bought the display unit after 2009.12.25 Please use the 9V for the Power supply. 12v also OK. ___ 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] TBolt OCXO replacement
That gets you to the question - just how good do you think the 1 second AVAR is on the existing oscillator, independent of the TBolt environment? If for instance you have a 2.5x10^-12 OCXO in yours, you would only see a significant improvement with a sub 1.0x10^-12 OCXO. That sort of bounds your OCXO shopping list right there. Several 5061As have been appearing on eBay lately and selling for decent prices in the $400 range, with unknown tube condition. There's no reason to think the tubes are any good, but what I did notice in the photos is that they seem to be late enough models to have the 10811-60109 oscillators installed. I have two of those (one in a working 5061A and one from a dead 5061A which is presently installed in my Thunderbolt) and have just recently been able to start looking at their performance, using a 5065A (which also has a -60109 OCXO). So far I'm impressed. When I disable disciplining in the Thunderbolt, the oscillator tends to stay well below 1E-12 until t=1000 seconds. The one in the 5061A doesn't seem quite as stable, but then it hasn't been enclosed in an unventilated chassis and left on for a couple of months, the way the one in the Thunderbolt has been. I still need to do a couple of overnight runs on that one to see how it behaves. Warren has spent a lot of time tinkering with this Thunderbolt remotely via the Heather server, and has been running it with a 750-second time constant, damping factor 0.75. I want to do some further tests to see what effects the elevation mask and AMU filter have on the actual ADEV performance. It is still falling short of Tom's best HP 58503A clock, but perhaps with some more tweaking we'll get it down below 1E-12 with disciplining turned on. -- john, KE5FX attachment: TBolt_10811_undisc_vs_disc.gif___ 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] TBolt OCXO replacement
Hi Nothing is ever perfect. The magic can only do just so well. The lower the aging rate, the better the result after correction. A little more detail: Take a number, maybe 10 ns and call it the error of the GPS signal. Over a 1 second period, that' s not so good (10 ppb). Over 10,000 seconds (~3 hours) it's better (1 ppt). Wait for a day and it's quite good (0.1 ppt). Wait a couple of weeks and it's tough to beat ( 1.0 x 10^-14). If you take a different number for error all of that will directly scale. The problem is - all of that takes *time*. The more stable the OCXO the better it can smooth out the variations in GPS. That of course assumes that you crank out the time constant of the loop to make that be true. Bob On Feb 16, 2010, at 6:28 PM, Henry Hallam wrote: Timing newbie here, so please educate me - why does aging matter? Isn't the whole purpose of a GPSDO to completely eliminate long-term drift? Thanks Henry On Tue, Feb 16, 2010 at 2:36 PM, Bob Camp li...@cq.nu wrote: Hi A similar question though would be - once you have done all the corrections to the setup of the TBolt (damping, time constant, sensitivity) what's left to fix? I would *guess*: Lower aging Better TC Better short term Aging will likely get better the longer you leave the existing oscillator on power. You also may be able to pick between units to find the best of 4 or something like that. TC can be improved a number of ways simply by helping the existing part. I think we have gone over that in about 300,000 messages so far. Short term stability is about the only thing I can see that's still on the list. That gets you to the question - just how good do you think the 1 second AVAR is on the existing oscillator, independent of the TBolt environment? If for instance you have a 2.5x10^-12 OCXO in yours, you would only see a significant improvement with a sub 1.0x10^-12 OCXO. That sort of bounds your OCXO shopping list right there. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Scott Newell Sent: Tuesday, February 16, 2010 1:06 PM To: time-nuts@febo.com Subject: Re: [time-nuts] TBolt OCXO replacement At 11:37 AM 2/16/2010 , WarrenS wrote: In the ever ending battle to improve my TBolt's performance, I am in the process of upgrading a OCXO replacement I did to it a while back. It would be Interesting to hear suggestions from others that have done similar sort of things and the results they have achieved. Did you check out John Miles's writeup? http://www.thegleam.com/ke5fx/tbolt.htm ___ 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. -- Henry Hallam Sent from my Laptop ___ 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] TBolt OCXO replacement
Henry Hallam wrote: Timing newbie here, so please educate me - why does aging matter? Isn't the whole purpose of a GPSDO to completely eliminate long-term drift? First degree effect yes, but depending on how you do it, more or less of the drift remains uncompensated. If you just try to do frequency compensation, drift is uncompensated and a second-degree PI-regulator will have a phase shift in its chase of frequency and also then a frequency error (it compensates the frequency it had a while ago). Linear drift compensation (such as PII²-regulator) would work better, if only the oscillator had true linear drift... which they don't. Various elaborate algorithms exists to handle both tempco and drift (both important in hold-over operation), the Thunderbolt is not doing too advanced tricks. A low-drifter would certainly help, but to be meaningful tempco also needs to be considered. Cheers, Magnus ___ 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] TBolt OCXO replacement
On Tue, 16 Feb 2010 15:28:11 -0800, Henry Hallam wrote: ... - why does aging matter? Isn't the whole purpose of a GPSDO to completely eliminate long-term drift? Aging? This remembers me on something... .When I get older, losing my hair - ... ...will you still need me, will you still feed me, when... ;-) Oscillators are sometimes well behaving just like humans... slowing down etc... they need a little help... food, pacemaker, something more ? ;-) friendly greetings Arnold ___ 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] Fluke1 Monitor
I cut the lead on pin 4 of the RS-232 connector and hooked it to +12 vdc. That way I eliminate using another supply. Seems to work alright. Just need to make sure that pin 4 of the Computer's Serial Port doesn't have a compatibility problem. (Just means I can't hook up a computer to the T-Bolt if there is). 73, Dick, W1KSZ -Original Message- From: Mike Naruta AA8K a...@comcast.net Sent: Feb 16, 2010 4:44 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] ko4bb monitor Thunderbolt PRECISION GPS 10mhz Standard's LED Monitor I received two from fluke.l 16 days after I sent my PayPal payment. It was well-packaged and he fit both in one box to save me shipping costs. They came with a DB-9P already soldered on the cable and a typical DC power jack. He even included shells for the DB-9P. They both powered up fine and started talking with my Thunderbolts right away. Current drain is about 75 ma at start-up and then falls to 50 ma (13.6 volts). It's not Lady Heather, but I can monitor my TBolts at a glance without tying up PCs. Mike - AA8K Arthur Dent wrote: The display I got from fluke.l (ordered 12-4-09) ran on +5V but the one I got from Amazon had a 3-terminal regulator and would run from 7-20V and was designed for +12V. I just noticed Bob's Ebay listing has been changed to add this note: because of some reasons,i change one IC on the PCB, so the buyer whom bought the display unit after 2009.12.25 Please use the 9V for the Power supply. 12v also OK. ___ 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] Hands on digital clock
It seems to me there is a way to make the segments folding so they could be changed without removing and inserting boards. Kind of like a folding ruler. I'll have to do some experiments with scraps of wood in my shop. On a smaller scale of course. Several years ago, I walked by one of the solar powered radar sets that shows you your speed on a pair of big 7 segment displays. It was clicking as the displayed speed changed so I stopped to look at it. The segments rotate about the long axis. So think of flipping the ruler segments over rather than folding them. -- 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] OT - RF Mailing list
Is there a RF Mailing list that anybody would like recommend? I am mostly interested in homebrew lower frequency (500KHz - 220MHz) range --- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. --- ___ 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] Hands on digital clock
-Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Tuesday, February 16, 2010 4:25 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Hands on digital clock It seems to me there is a way to make the segments folding so they could be changed without removing and inserting boards. Kind of like a folding ruler. I'll have to do some experiments with scraps of wood in my shop. On a smaller scale of course. Several years ago, I walked by one of the solar powered radar sets that shows you your speed on a pair of big 7 segment displays. It was clicking as the displayed speed changed so I stopped to look at it. The segments rotate about the long axis. So think of flipping the ruler segments over rather than folding them. Those are very nifty displays. I can't recall when I first saw them, but it has to have been back in the 80s or perhaps 70s. The display element is magnetized, and they have a coil behind it that gets either a positive or negative pulse to flip it. I seem to recall some sort of capacitor and SCR circuit was used. They're nice because they don't consume any power when not changing, and can be artificially illuminated as bright as you like. The signaling is pretty robust, so you can put the display at the end of a long wire, too. They aren't very fast, though. You couldn't display motion video. But for a time nut? Sure. You could carefully balance them for aerodynamics, and actuate them with floats and falling weights from your clepsydra, for instance. Some sort of fluidic water level to 7 segment decoder would be needed, but that could be very fun to design with buckets and counterweights (e.g. you make a 3 input AND gate with a bucket that holds 3 liters of water, counterweighted with a 2.5 kg weight) Hmm, you sort of inherently get a thermometer code from a clepsydra, so you need a thermometer to 7 segment decoder. I envision a giant jacquard loom or piano roll scheme, with holes to fill or drain the weights that turn the segments. Air pressure is also legal, I suppose. It kind of depends on whether you need it to be totally gravity driven, or whether a pump/compressor is ok. (If you've ever seen the Villa d'Este in Tivoli, near Rome, you'd be amazed at what can be done with air and water pressure, ALL gravity fed) http://en.wikipedia.org/wiki/Villa_d%27Este (which is actually a pretty lame description) google for villa d'este organ fountain and you'll turn up some youtube video. http://www.youtube.com/watch?v=gGJumf6m44M is one of them ___ 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] OT - RF Mailing list
Jerome Peters wrote: Is there a RF Mailing list that anybody would like recommend? I am mostly interested in homebrew lower frequency (500KHz - 220MHz) range http://www.50mhzandup.org/ Rick N6RK ___ 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] Hands on digital clock
-Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Tuesday, February 16, 2010 5:01 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Hands on digital clock Lux, Jim (337C) wrote: (If you've ever seen the Villa d'Este in Tivoli, near Rome, you'd be amazed at what can be done with air and water pressure, ALL gravity fed) http://en.wikipedia.org/wiki/Villa_d%27Este (which is actually a pretty lame description) google for villa d'este organ fountain and you'll turn up some youtube video. http://www.youtube.com/watch?v=gGJumf6m44M is one of them As I recall it, it was an hours bus ride from Termini, so it is a nice day-activity to leave Rome and visit Villa d'Este and Tivoli. It was a bit cold when I was there over 20 years ago. About 2 hrs on the Metro and COTRAL bus. Big difference between getting the local and the express bus. The colder temperature is an advantage in the summer, when Rome is hot. That's why Hadrian built his palace up there, and later Pope Ippolito(?) did too. Hmm... fluidistor counter, BCD decoder feeding small sprinklers for fluid-digital display? PPS electrical input controlling a single electrical-to-air-burst conversion. GPS-controlled of-course. :) Should be possible to implement. :) Something like a pps (or ppminute) to tipping bucket to dump quanta of water into the clock is what I was thinking. Of course, a more sophisticated approach would be to use the pps to discipline a more conventional (as in what the Greeks used) continuous flow regulator (i.e. a constant level in a container and a small hole). You'd need to compensate for temperature effects on the orifice size and the viscosity of the water (maybe there's a clever way to self compensate? You want the hole bigger as it gets colder, because the water gets more viscous (in an exponential relationship, I think), otoh, it depends if your clepsydra is mass or volume driven) Cheers, Magnus ___ 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] OT - RF Mailing list
Jerome Peters wrote: Is there a RF Mailing list that anybody would like recommend? I am mostly interested in homebrew lower frequency (500KHz - 220MHz) range You may find http://groups.yahoo.com/group/emrfd of interest. Messages are publicly available so you can read and decide before joining. gc ___ 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] Hands on digital clock
Hi Jim: I have samples of two sizes of flipping dot displays, see: http://www.prc68.com/I/LED.shtml#FD was going to see how fast they can be flipped using high voltage drive with a series resistor to lower the time constant, but other things got in the way. Have Fun, Brooke Clarke http://www.PRC68.com Lux, Jim (337C) wrote: -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Tuesday, February 16, 2010 4:25 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Hands on digital clock It seems to me there is a way to make the segments folding so they could be changed without removing and inserting boards. Kind of like a folding ruler. I'll have to do some experiments with scraps of wood in my shop. On a smaller scale of course. Several years ago, I walked by one of the solar powered radar sets that shows you your speed on a pair of big 7 segment displays. It was clicking as the displayed speed changed so I stopped to look at it. The segments rotate about the long axis. So think of flipping the ruler segments over rather than folding them. Those are very nifty displays. I can't recall when I first saw them, but it has to have been back in the 80s or perhaps 70s. The display element is magnetized, and they have a coil behind it that gets either a positive or negative pulse to flip it. I seem to recall some sort of capacitor and SCR circuit was used. They're nice because they don't consume any power when not changing, and can be artificially illuminated as bright as you like. The signaling is pretty robust, so you can put the display at the end of a long wire, too. They aren't very fast, though. You couldn't display motion video. But for a time nut? Sure. You could carefully balance them for aerodynamics, and actuate them with floats and falling weights from your clepsydra, for instance. Some sort of fluidic water level to 7 segment decoder would be needed, but that could be very fun to design with buckets and counterweights (e.g. you make a 3 input AND gate with a bucket that holds 3 liters of water, counterweighted with a 2.5 kg weight) Hmm, you sort of inherently get a thermometer code from a clepsydra, so you need a thermometer to 7 segment decoder. I envision a giant jacquard loom or piano roll scheme, with holes to fill or drain the weights that turn the segments. Air pressure is also legal, I suppose. It kind of depends on whether you need it to be totally gravity driven, or whether a pump/compressor is ok. (If you've ever seen the Villa d'Este in Tivoli, near Rome, you'd be amazed at what can be done with air and water pressure, ALL gravity fed) http://en.wikipedia.org/wiki/Villa_d%27Este (which is actually a pretty lame description) google for villa d'este organ fountain and you'll turn up some youtube video. http://www.youtube.com/watch?v=gGJumf6m44M is one of them ___ 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] OT - RF Mailing list
You need to state your interests a bit more. is it ham radio ? Is it general RF analog ? Is it digital modulation modes ? For 500 KHz, part 5, part 15, 137 KHz, 160-190 KHz and 500 KHz look to: Lowfer mailing list Home: http://mailman.qth.net/mailman/listinfo/lowfer Help: http://mailman.qth.net/mmfaq.htm Post: mailto:low...@mailman.qth.net If it is 50 MHz and above, VHF.UHF look to: Submissions:v...@w6yx.stanford.edu Subscription/removal requests: vhf-requ...@w6yx.stanford.edu Human list administrator: vhf-appro...@w6yx.stanford.edu List rules and information:http://www-w6yx.stanford.edu/vhf/ Stan, W1LE Cape CodFN41sr Jerome Peters wrote: Is there a RF Mailing list that anybody would like recommend? I am mostly interested in homebrew lower frequency (500KHz - 220MHz) range ___ 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] OT - RF Mailing list
The 50MHz and Up Group of N. Calif primarily has members who really prefer 900MHz and up. When I first formed it, I did invite speakers about 6m and 2m DXing however, since then there has not been much interest in those low frequencies. However, anyone is definitely welocme to join as either a member or an out-of-the-area friend. There are no dues this year for members. Rick - fill out the memberform 73, Jeffrey Pawlan WA6KBL ___ 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] iPhone app
Hi all, Having recently acquired a new iPhone with a built in GPS, I was wondering if anyone is aware of an application that uses the GPS 1PPS to produce accurate time. I seem to remember reading somewhere that it is not possible to adjust the internal clock, but one could still produce an accurate time display based on the GPS 1 PPS and even provide time pips. Combine that with the internal video there seems a myriad of possibilities. However, trying to find such applications is a large effort and I was hoping the time-nuts community may be aware of some time-aware cleverness on the iPhone. Regards, Jim Palfreyman ___ 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] iPhone app
I don't believe that there is a 1pps available to the OS. The GPS chipset seems to provide a very limited amount of data to the phone. For example, there does not appear to be any way to get satellite status info from the GPS chip to the OS. At least none of the apps I've tried thus far (and I've tried a fair number) provide anything like that. Tom Frank On Feb 17, 2010, at 12:23 AM, Jim Palfreyman wrote: Hi all, Having recently acquired a new iPhone with a built in GPS, I was wondering if anyone is aware of an application that uses the GPS 1PPS to produce accurate time. I seem to remember reading somewhere that it is not possible to adjust the internal clock, but one could still produce an accurate time display based on the GPS 1 PPS and even provide time pips. Combine that with the internal video there seems a myriad of possibilities. However, trying to find such applications is a large effort and I was hoping the time-nuts community may be aware of some time-aware cleverness on the iPhone. Regards, Jim Palfreyman ___ 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] FE5680 Frequency adjustment voltage range
Angus informed that the two buttons are for shifting the freq. up or down, after one single click the adjustment range is around the center. Suspect thats adjusting the c field. Would not hurt especially if the unit was used/surplus. Try 4000. On Mon, Feb 15, 2010 at 12:44 AM, Raj vu2...@gmail.com wrote: In my FE5680, I find that the trimpot for frequency adjust at one end 4.4V. The upper and lower voltages are 4.4 and 5.2 approx. Does this mean it is at the end of its life? There is a 4750 Resistor connected to the low end of the trimpot whose value can be reduced as a solution. Any experiences? -- Raj, VU2ZAP Bangalore, India. ___ 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.
