Re: [time-nuts] Looking for high reverse isolation amplifier
Depending on how much forward gain you're after, I'd suggest looking at the LMH6702 current feedback opamp. I keep a few of them around in Hammond boxes, powered by NiMH rechargeables. Measured S12 is about 70 dB at 100 MHz, and I'm sure it could do at least 40 dB at 200. If I remember correctly the 3 dB point is about 400 MHz in a stage designed for +8 dB of gain, and unity gain is about 700 MHz. Residual PN at 80 MHz is around -135 dBc/Hz @ 1 Hz, flicker corner around 1 kHz, floor around -165 dbc/Hz. You can do better with discretes but you can also do a lot worse... -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Richard (Rick) Karlquist Sent: Wednesday, January 29, 2014 10:25 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Looking for high reverse isolation amplifier Can anyone direct me to an amplifier with: 1. High reverse isolation (over 40 dB). Note: the spec of interest is *reverse* isolation, not port to port isolation in a distribution amplifier. 2. Low phase noise (less than -100 dBc/Hz at 1 Hz offset) 3. Works at 200 MHz The Q-Bit QBH-1401PM seems promising...if I can get one. If necessary I will build the amplifier if I can get a known good schematic to follow, but prefer to buy one. Thanks in advance. Rick Karlquist 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. ___ 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] Morion MV89A position
In message 8A80321A376D46AE916CF00748A60F4F@athlon3200, Dave Brown writes: So, rather than invest heavily in a higher capacity battery bank, I'm looking to get the lowest energy requirement for the essential things like reference oscillators and a minor amount of logging eqpt. Put a solar panel on your battery ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Re(2); wa4hhg ....
http://chealseafc.tym.cz/labofit/for.u.info.bro.html From: B Riches 1/30/2014 9:48:26 AM ___ 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] Morion MV89A position
In the 70's I did a 4 inch pipe 20 feet in the ground in Dallas. Temperature was better than 0.1 C. Over what time period? Dry ground or wet? How deep is your water table? ... Temperature in the ground is a skin-depth problem. Lower frequencies will go deeper. Next time somebody digs a hole like that, it would be fun to put a string of thermometers in it. Goodies from google: http://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm http://topex.ucsd.edu/geodynamics/HW3_2011_presentations/C_wine_cellar.pdf -- These are my opinions. 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] Re(7): time nuts bounces
http://bhaskargroup.com/home_job_place/start-s.new.life_here.html _ From: B Riches 1/30/2014 12:31:14 PM ___ 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] Morion MV89A position
This was in the 70's and I only looked at it for a month in those days also limited equipment and I used a Tracor 599 for frequency tracking. Location was University Park in Dallas which is elevated so there was no water present. Left 20 years ago so I have no way of conducting any tests. Could repeat it but I am looking at an other relocation. Bert Kehren In a message dated 1/30/2014 4:44:08 A.M. Eastern Standard Time, hmur...@megapathdsl.net writes: In the 70's I did a 4 inch pipe 20 feet in the ground in Dallas. Temperature was better than 0.1 C. Over what time period? Dry ground or wet? How deep is your water table? ... Temperature in the ground is a skin-depth problem. Lower frequencies will go deeper. Next time somebody digs a hole like that, it would be fun to put a string of thermometers in it. Goodies from google: http://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm http://topex.ucsd.edu/geodynamics/HW3_2011_presentations/C_wine_cellar.pdf -- These are my opinions. 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 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] interesting oscillator setup.... Symmetricom
Hey All, I recently came into a few CO clock modules made by Symmetricom, Austron, etc. These were Stratum 3E level clocks. One of the modules can be seen here pictures 2,3,4 http://rescueelectronics.com/timeplot The module ran in the position where the heatsink fins were vertical. The heatsinks had nothing to do in this module as there no active component connected to it If you look closely you can see that the actual oscillator is electrically isolated from the alum. holder. There were really no power components on the module that needed cooling. Then I thought, could this be an example of thermal capacitance in play here. Three is a lot of thermal mass not directly connected to the oscillator, What do you guys think? BTW if anyone could help me with me pin outs for this unit I would be much obliged Thank you PauLC W1VLF ___ 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] GR 1115-C from the E
Pete Sorry to see what happened to the oscillator. Given how protected the crystal was curious as to the damage. Pretty sure you can't glue it back together. But that said at least for fun perhaps some other xtal will work. (Not as well) I see the nicads leaked a bit. Those are really old units. I would guess circa 1960. Amazed its not far worse. You do find the rare odds and ends. Regards Paul WB8TSL On Wed, Jan 29, 2014 at 10:41 PM, Pete Lancashire p...@petelancashire.comwrote: Some bad news The unit on the E looked very clean, hardly a scratch. Explained to the seller how things like rack mount equipment can take a hit where the ears stick out (front panel in this case), handles etc. I paid and extra $20 to have it double boxed and it arrived with the outer box in pretty good shape. The seller did not respond to my query if it could go some other shipper such as FedEx Ground. When I took it out of the box one could hear a faint rattle inside, first thought typical GR, a screw came loose. Typical in that GR in many cases did not use lock washers on some screws/nuts for some reason. The next day, I pulled off the cover and one could see little bits of glass .. hmm ...some were silvered. Well off came the snap cover to the end of the oven assenbly and I'll let the pictures do the talking http://goo.gl/1XZnkI I've asked the seller if s/he heard any rattle noises when s/he packed it up -pete BTW goo.gl is Google's URL shortener ___ 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] Morion MV89A position
I copied this message to this thread as it may some bearing on the Thermal Capacitance, resistance etc. discussion. Sorry if you already saw this, if not see below. PauLC W1VLF Hey All, I recently came into a few CO clock modules made by Symmetricom, Austron, etc. These were Stratum 3E level clocks. One of the modules can be seen here pictures 2,3,4 http://rescueelectronics.com/timeplot The module ran in the position where the heatsink fins were vertical. The heatsinks had nothing to do in this module as there no active component connected to it If you look closely you can see that the actual oscillator is electrically isolated from the alum holder. There were really no power components on the module that needed cooling. Then I thought, could this be an example of thermal capacitance in play here. Three is a lot of thermal mass not directly connected to the oscillator, What do you guys think? BTW if anyone could help me with me pin outs for this unit I would be much obliged Thank you PauLC W1VLF ___ 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] Tom's Adventures of a Time Nut (Banquet Talk)
Today's SouthGateARC.org page has a link to Tom's talk at the 2013 TAPR/ARRL Digital Communications Conference. I don't know whether this has been linked to time nuts in the past, but it's an enjoyable presentation. southgatearc.org/news/2014/january/adventures_of_a%20_time_nut.htm#.UuqiQ5Uiwag Bob - AE6RV ___ 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] GR 1115-C from the E
The NiCad's in the 1115 are the vented type. Nice that GR put them in a 'bag'. One cool thing about these cell is you can take them out, wash them and if needed refill them. The Potassium hydroxide electrolyte as long is easily cleaned off. And looks like it was contained in the 'bag'. I just got an email back from the seller, s/he didn't hear anything, but then if one was not and old equipment nut, one may not have been listening. I'm going to have the seller file a claim and see what happens. Since the rest of the unit is in such nice shape, I'm going to keep it and hope to find another oven. BTW I'll bet the size of the Thermos bottle GR used was not a custom size. It more then likely was a off the shelf dewar, Once I'm done with UPS I'll make some measurments. The oven does not want to come out. My guess is GR made a mold where they applied the ridged foam around the bottle and either press fit the oven into the bottom of the bottle. Over time it has become 'attached' to the foam. The thickness of the foam on the inside of the bottle looks to be about 1/8th inch. -pete On Thu, Jan 30, 2014 at 5:34 AM, paul swed paulsw...@gmail.com wrote: Pete Sorry to see what happened to the oscillator. Given how protected the crystal was curious as to the damage. Pretty sure you can't glue it back together. But that said at least for fun perhaps some other xtal will work. (Not as well) I see the nicads leaked a bit. Those are really old units. I would guess circa 1960. Amazed its not far worse. You do find the rare odds and ends. Regards Paul WB8TSL On Wed, Jan 29, 2014 at 10:41 PM, Pete Lancashire p...@petelancashire.comwrote: Some bad news The unit on the E looked very clean, hardly a scratch. Explained to the seller how things like rack mount equipment can take a hit where the ears stick out (front panel in this case), handles etc. I paid and extra $20 to have it double boxed and it arrived with the outer box in pretty good shape. The seller did not respond to my query if it could go some other shipper such as FedEx Ground. When I took it out of the box one could hear a faint rattle inside, first thought typical GR, a screw came loose. Typical in that GR in many cases did not use lock washers on some screws/nuts for some reason. The next day, I pulled off the cover and one could see little bits of glass .. hmm ...some were silvered. Well off came the snap cover to the end of the oven assenbly and I'll let the pictures do the talking http://goo.gl/1XZnkI I've asked the seller if s/he heard any rattle noises when s/he packed it up -pete BTW goo.gl is Google's URL shortener ___ 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] *bay (cheap) - Datum 6502 Frequency Distribution Amplifier 10 Channels
Until now it's quite cheap *Bay #141175251426 CFO ___ 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] Piezo Company OXCO pinouts (William Rice)
Hi William, I just joined time-nuts and found the posts on the Piezo 2920136 interesting, in particular the 12 volt/24 volt issue. I had just purchased two units (S/N 4690 and 9646) and I ran some voltage tests on them. It came out clear that the units are designed to run on 24 volts. The key test is to run the supply voltage slowly from 12 to 24 volts and note the output frequency change as you go. On my units the output frequency was very sensitive to the supply voltage in the range of 12 and about 20 volts. As the voltage was increased from 20 to 24 volts there was almost no frequency change. I think this indicates that an internal voltage regulator is used in the crystal circuitry and that it needs at least 20 volts to work. Jim Teixeira ___ 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] Tom's Adventures of a Time Nut (Banquet Talk)
I remember they recorded it. I just found out today it's on YouTube! Cool. I guess. It's always weird to hear or see oneself speak, but if you watch it I think it describes the time nut hobby pretty well. If you want to follow the PowerPoint presentation instead of the long talk, a copy if it is here: http://leapsecond.com/dcc2013/ /tvb - Original Message - From: Bob Stewart b...@evoria.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 30, 2014 11:11 AM Subject: [time-nuts] Tom's Adventures of a Time Nut (Banquet Talk) Today's SouthGateARC.org page has a link to Tom's talk at the 2013 TAPR/ARRL Digital Communications Conference. I don't know whether this has been linked to time nuts in the past, but it's an enjoyable presentation. southgatearc.org/news/2014/january/adventures_of_a%20_time_nut.htm#.UuqiQ5Uiwag Bob - AE6RV ___ 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] Tom's Adventures of a Time Nut (Banquet Talk)
Tom- A friend of mine John Delaney, of Delaney Antique Clocks (who has sold me some VERY nice 210+ yr old tall clocks made in my home town in Vermont) was there and told me he was impressed with your talk and that he now closed the loop with the idea of the Time Nuts which I told him I was involved with at the other-end of time keeping. So for me.it's $20k for an extra Cs or the same for a clock that's over 200 years old that was made where I call home. I still need to synch an old clock to GPS, but have yet to work out the issue when I wind the clock once a week it takes load off the weight and the clock loses time. Yet another problem to solve. -Brian, WA1ZMS/4 iPhone On Jan 30, 2014, at 7:04 PM, Tom Van Baak t...@leapsecond.com wrote: I remember they recorded it. I just found out today it's on YouTube! Cool. I guess. It's always weird to hear or see oneself speak, but if you watch it I think it describes the time nut hobby pretty well. If you want to follow the PowerPoint presentation instead of the long talk, a copy if it is here: http://leapsecond.com/dcc2013/ /tvb - Original Message - From: Bob Stewart b...@evoria.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 30, 2014 11:11 AM Subject: [time-nuts] Tom's Adventures of a Time Nut (Banquet Talk) Today's SouthGateARC.org page has a link to Tom's talk at the 2013 TAPR/ARRL Digital Communications Conference. I don't know whether this has been linked to time nuts in the past, but it's an enjoyable presentation. southgatearc.org/news/2014/january/adventures_of_a%20_time_nut.htm#.UuqiQ5Uiwag Bob - AE6RV ___ 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] Tom's Adventures of a Time Nut (Banquet Talk)
Oppps! Thought I deleted the reflector e-mail! Sorry for BW. I am blushing. :- ( -Brian, WA1ZMS/4 iPhone On Jan 30, 2014, at 7:16 PM, Brian, WA1ZMS wa1...@att.net wrote: Tom- A friend of mine John Delaney, of Delaney Antique Clocks (who has sold me some VERY nice 210+ yr old tall clocks made in my home town in Vermont) was there and told me he was impressed with your talk and that he now closed the loop with the idea of the Time Nuts which I told him I was involved with at the other-end of time keeping. So for me.it's $20k for an extra Cs or the same for a clock that's over 200 years old that was made where I call home. I still need to synch an old clock to GPS, but have yet to work out the issue when I wind the clock once a week it takes load off the weight and the clock loses time. Yet another problem to solve. -Brian, WA1ZMS/4 iPhone On Jan 30, 2014, at 7:04 PM, Tom Van Baak t...@leapsecond.com wrote: I remember they recorded it. I just found out today it's on YouTube! Cool. I guess. It's always weird to hear or see oneself speak, but if you watch it I think it describes the time nut hobby pretty well. If you want to follow the PowerPoint presentation instead of the long talk, a copy if it is here: http://leapsecond.com/dcc2013/ /tvb - Original Message - From: Bob Stewart b...@evoria.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 30, 2014 11:11 AM Subject: [time-nuts] Tom's Adventures of a Time Nut (Banquet Talk) Today's SouthGateARC.org page has a link to Tom's talk at the 2013 TAPR/ARRL Digital Communications Conference. I don't know whether this has been linked to time nuts in the past, but it's an enjoyable presentation. southgatearc.org/news/2014/january/adventures_of_a%20_time_nut.htm#.UuqiQ5Uiwag Bob - AE6RV ___ 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] Tom's Adventures of a Time Nut (Banquet Talk)
Great video Tom. I forwarded it to some friends. 73 even if you are not a ham :). - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: Thursday, January 30, 2014 7:05 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Tom's Adventures of a Time Nut (Banquet Talk) I remember they recorded it. I just found out today it's on YouTube! Cool. I guess. It's always weird to hear or see oneself speak, but if you watch it I think it describes the time nut hobby pretty well. If you want to follow the PowerPoint presentation instead of the long talk, a copy if it is here: http://leapsecond.com/dcc2013/ /tvb - Original Message - From: Bob Stewart b...@evoria.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 30, 2014 11:11 AM Subject: [time-nuts] Tom's Adventures of a Time Nut (Banquet Talk) Today's SouthGateARC.org page has a link to Tom's talk at the 2013 TAPR/ARRL Digital Communications Conference. I don't know whether this has been linked to time nuts in the past, but it's an enjoyable presentation. southgatearc.org/news/2014/january/adventures_of_a%20_time_nut.htm#.UuqiQ5Ui wag Bob - AE6RV ___ 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] Looking for high reverse isolation amplifier
On 1/30/2014 12:30 AM, John Miles wrote: Depending on how much forward gain you're after, I'd suggest looking at the LMH6702 current feedback opamp. I keep a few of them around in Hammond boxes, powered by NiMH rechargeables. Measured S12 is about 70 dB at 100 MHz, and I'm sure it could do at least 40 dB at 200. If I remember correctly the 3 dB point is about 400 MHz in a stage designed for +8 dB of gain, and unity gain is about 700 MHz. Residual PN at 80 MHz is around -135 dBc/Hz @ 1 Hz, flicker corner around 1 kHz, floor around -165 dbc/Hz. You can do better with discretes but you can also do a lot worse... -- john, KE5FX Miles Design LLC Great suggestion! TI has eval boards available for them so I can get up to speed quickly. I guess the idea is that I set it up for a gain of 2, and put a 50 ohm resistor in series with the output. Now it is a unity gain buffer in a 50 ohm system. A signal trying to go through it backwards has a source impedance of 100 ohms driving the output impedance of the amplifier, which is spec'ed at 30 milliohms, at least at low frequencies. That works out to 70 dB, which is what you observed. So I can see how it could have good reverse isolation. Do you run it in inverting or non-inverting configuration? 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] Looking for high reverse isolation amplifier
Great suggestion! TI has eval boards available for them so I can get up to speed quickly. I guess the idea is that I set it up for a gain of 2, and put a 50 ohm resistor in series with the output. Now it is a unity gain buffer in a 50 ohm system. A signal trying to go through it backwards has a source impedance of 100 ohms driving the output impedance of the amplifier, which is spec'ed at 30 milliohms, at least at low frequencies. That works out to 70 dB, which is what you observed. So I can see how it could have good reverse isolation. Exactly, for unity gain you'd design for +6 dB and series-terminate the output with 50R. Good for capacitive loads as well as isolation. Do you run it in inverting or non-inverting configuration? I've only used the non-inverting configuration (figure 1 from the datasheet). Takes about 20 minutes to dead-bug with 0603 resistors over bare copper. -- john, KE5FX Miles Design LLC ___ 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] Tom's Adventures of a Time Nut (Banquet Talk)
Tom. Could you give us a link to the u tube version. I haven't mastered searching on u tube yet. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html 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 To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: Tom Van Baak t...@leapsecond.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 30, 2014 6:04 PM Subject: Re: [time-nuts] Tom's Adventures of a Time Nut (Banquet Talk) I remember they recorded it. I just found out today it's on YouTube! Cool. I guess. It's always weird to hear or see oneself speak, but if you watch it I think it describes the time nut hobby pretty well. If you want to follow the PowerPoint presentation instead of the long talk, a copy if it is here: http://leapsecond.com/dcc2013/ /tvb - Original Message - From: Bob Stewart b...@evoria.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 30, 2014 11:11 AM Subject: [time-nuts] Tom's Adventures of a Time Nut (Banquet Talk) Today's SouthGateARC.org page has a link to Tom's talk at the 2013 TAPR/ARRL Digital Communications Conference. I don't know whether this has been linked to time nuts in the past, but it's an enjoyable presentation. southgatearc.org/news/2014/january/adventures_of_a%20_time_nut.htm#.UuqiQ5Uiwag Bob - AE6RV ___ 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.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.
[time-nuts] The pendulum problem...
Now that I have exposed myself as being an antique time-nut as well as a modern one, (I'm a man of extremes!) I have a question to the group.. Has anyone addressed the issue of trying to keep a pendulum clock locked to an external reference (i.e.: via electro-magnet, etc.) and yet can work around the problem that very old pendulum clocks have an issue with the escapement drive stopping while such a typical 8-day antique clock is being wound? I can understand and deal with syncing the pendulum to an external reference.. but you end up with a time offset when the clock's main wheel is being wound once a week. The pendulum does keep swinging however the drive power to the 2nd gear is being removed while the clock is being wound. Modern pendulum clocks have a modified gear drive where the escapement is still being driven while the main wheel is being advanced to wind the weight cable. Not the case for 200+ year old clocks. Regards, -Brian, WA1ZMS/4 ___ 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.
