Re: [time-nuts] Help identifying a display board
It could be a combined time display with a channel number and measured value, from some kind of data logging instrument. LN was big in thermocouple measurements and the like. With those digits you could show temperature at three digits resolution, selected channel 00-99, and hours and minutes, with the LED for AM/PM. Or NOT. One clue would be to see if they used any of the Panaplex decimal points. None would be needed on time or channel readouts. If only the second DP of the three-digit one is connected, then it could be set to 1 or 0.1 degree resolution. If no DPs at all are used, then the temperature could show 1 degree resolution, and display -99 to 999 deg F or C, which is a pretty decent range for common T/Cs, depending on the application. It could even work for cryogenics, reading say 000-999 deg K. The board also appears to be missing one DM8880. Ed ___ 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] Digital Mixing with a BeagleBone Black and D Flip Flop
Simon, This is a fantastic idea and I have every intention of trying to replicate it at home with tools on hand. Thanks for sharing, and I hope you can show off some results. On Wed, Oct 8, 2014 at 1:09 PM, Simon Marsh subscripti...@burble.com wrote: I've been a lurker on time-nuts for a while, most of the discussion being way over my head, but I thought there may be interest in some proof of concept code I've written for simple digital hetrodyne mixing using just a BeagleBone Black and an external dual D Flip Flop. The idea is based on the following article which describes creating a digital DMTD with an FPGA for clocks @ 125mhz: http://www.ee.ucl.ac.uk/lcs/previous/LCS2011/LCS1136.pdf My setup follows the same principle, but scaled down to 10mhz to make it as simple as possible (and not require an FPGA). The hardware side is just a 74AC74 dual flip flop to sample the input clocks being tested. Instead of having a helper PLL for the mixer frequency, I simply have a 3rd, de-tuned oscillator. The output from the two flip-flops together with the mixer clock are fed to the BBB. On the BBB, the approach is to do as little as possible in real time using a PRU core, and then post-process on the ARM core afterwards. The BBB PRU has a 16-bit, asynchronous, parallel, capture mode, where 16 GPIO pins can be latched based on an external clock (described in section 4.4.1.2.3.2 of the TRM for those interested). In this case, the external clock is the mixer oscillator. All the PRU needs to do is wait for the sample to take place, read the GPIOs and store the results in main memory. The PRU is plenty fast enough to capture samples @10mhz and, in theory at least, each PRU could sample up to 16 clocks simultaneously (depending on whether the relevant GPIO pins were free). Once the sampling is complete, the ARM core can process the results in its own time, and this includes any more complicated algorithms for de-glitching etc The theoretical minimum time resolution depends on the beat frequency and is described in the article, for example with a beat frequency of 50 hz the minimum resolution is 50 / (1000 - 50)*1000 = ~5E-13. In practice the available accuracy is determined by the stability of the mixer clock and noise of the setup. The impact of this noise is described in the article as glitching and there are some suggested ways for processing this out. I'm trying this on an open bench, with basic oscillators, using pluggable breadboard and lots of hanging wires, I'm not at risk of getting near the theoretical limit quite yet :) Note that the BBB itself has no impact on the accuracy or noise of the raw data. Once the input is latched at the flip-flop, the only bit of critical timing required is to ensure that samples can be captured fast enough and that the flip-flop state is captured when it is stable (i.e. not transitioning). I make no excuses that this is very simplistic, and there are many, many ways that it can (should!) be improved. For me the next steps will probably be: 1) Get off the breadboard and focus a bit more on getting the signals to the flip-flop with a 'reasonable' amount of noise. 2) Improve the PRU code so that it stores transitions and not just the raw samples, this would offload a significant bit of work from the ARM core, save a load of memory and allow continuous streaming of data (instead of the current one shot approach). 3) Experimentation with different algorithms for processing the data on the ARM. I don't think anyone has posted a similar set up, so any feedback on whether the approach is viable or I'm wasting my time are welcome. I've posted the code to Google drive for anyone to take a look. It shouldn't be too difficult to reproduce if someone wants to, but again please remember it's just 'prove it can be done' code. https://drive.google.com/open?id=0BzvFGRfj4aFkblAwcWxGNHdCSDgauthuser=0 Cheers Simon ___ 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] Sun Outage
Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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] Sun Outage
Bob - I do not believe it has any effect. The DirecTV satellites are geostationary at about 22K miles. I used to experience the same phenomenon in the late 70's with my TVRO receiver at C band. GPS has some 36 or so satellites in a Medium Earth Orbit (MEO). Blockage, if it can even occur due to the nature of the receiving antenna, of a single one for a few minutes will have no discernible effect in my opinion. 73 - 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 [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 09, 2014 1:40 PM To: Time Nuts Subject: [time-nuts] Sun Outage Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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] Sun Outage
If you had an exact timing for the outage, would that have told you the beam-width of your antenna? -- project for next spring :-) On 10/9/2014 1:04 PM, Mike Feher wrote: Bob - I do not believe it has any effect. The DirecTV satellites are geostationary at about 22K miles. I used to experience the same phenomenon in the late 70's with my TVRO receiver at C band. GPS has some 36 or so satellites in a Medium Earth Orbit (MEO). Blockage, if it can even occur due to the nature of the receiving antenna, of a single one for a few minutes will have no discernible effect in my opinion. 73 - 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 [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 09, 2014 1:40 PM To: Time Nuts Subject: [time-nuts] Sun Outage Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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] Sun Outage
b...@evoria.net said: Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. Is there any easy way to get a signal/noise reading out of the receiver? It would be interesting to see a daily/weekly plot as well as the zoomed in area around things like sun events. What's the beam width of the DirectTV antennas? Does it agree with the 3 or 4 minutes at the back-of-envelope level? -- 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.
Re: [time-nuts] Sun Outage
Henry, I have more information and you may have explained it. The outages occurred at about 3:10PM, and with an azimuth here of about 180 degrees (which I just looked up), that makes no sense. Also, the cartoons I was recording for my granddaughter were unaffected, but the station I was watching had the outage. That doesn't all fit together unless it was the uplink that had the problem. I guess I should have checked all that before posting. Bob From: Henry Hallam he...@pericynthion.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Cc: Bob Stewart b...@evoria.net; hmur...@megapathdsl.net Sent: Thursday, October 9, 2014 2:27 PM Subject: Re: [time-nuts] Sun Outage On Thu, Oct 9, 2014 at 11:18 AM, Hal Murray hmur...@megapathdsl.net wrote: What's the beam width of the DirectTV antennas? Does it agree with the 3 or 4 minutes at the back-of-envelope level? DirecTV is a Ku/Ka-band system operating with a 460mm dish antenna. At Ka-band, the 3dB full-width of the beam is 2.4 degrees. The earth rotates at 0.25 degrees per minute, giving approx 10 minutes for the sun to cross the beam assuming it crosses directly through the center of the beam. However, a little googling[1] suggests that in fact the DirecTV satellite signal usually has enough margin to overcome the sun noise, but that the C-band feed[2] that DirecTV uses at their uplink station to receive programs from their providers may itself suffer from solar conjunctions. Henry [1] http://www.dbstalk.com/topic/202779-sun-interference-message/ [2] http://www.prss.org/solar-outage-rules ___ 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] Sun Outage
On Thu, Oct 9, 2014 at 11:18 AM, Hal Murray hmur...@megapathdsl.net wrote: What's the beam width of the DirectTV antennas? Does it agree with the 3 or 4 minutes at the back-of-envelope level? DirecTV is a Ku/Ka-band system operating with a 460mm dish antenna. At Ka-band, the 3dB full-width of the beam is 2.4 degrees. The earth rotates at 0.25 degrees per minute, giving approx 10 minutes for the sun to cross the beam assuming it crosses directly through the center of the beam. However, a little googling[1] suggests that in fact the DirecTV satellite signal usually has enough margin to overcome the sun noise, but that the C-band feed[2] that DirecTV uses at their uplink station to receive programs from their providers may itself suffer from solar conjunctions. Henry [1] http://www.dbstalk.com/topic/202779-sun-interference-message/ [2] http://www.prss.org/solar-outage-rules ___ 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] Sun Outage
Standard GPS receiving antennas have a large beam width in order to cover most of the sky. Even in the Oregon Rainforest the sun is in view most of the day. Some satellite transponders have more power and are less prone to interference as they pass in front of the sun. Typical home TVROs have a number of feedhorns to receive more than one satellite. Different satellites will be affected at different times. On 10/09/2014 10:40 AM, Bob Stewart wrote: Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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. -- Chuck Forsberg WA7KGX c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] Sun Outage
Exactly geosyncs have sun outages as the sun aligns with the sat and your dish. GPS because the sats are distributed do not suffer from the effect. Regards Paul WB8TSL On Thu, Oct 9, 2014 at 2:04 PM, Mike Feher mfe...@eozinc.com wrote: Bob - I do not believe it has any effect. The DirecTV satellites are geostationary at about 22K miles. I used to experience the same phenomenon in the late 70's with my TVRO receiver at C band. GPS has some 36 or so satellites in a Medium Earth Orbit (MEO). Blockage, if it can even occur due to the nature of the receiving antenna, of a single one for a few minutes will have no discernible effect in my opinion. 73 - 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 [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 09, 2014 1:40 PM To: Time Nuts Subject: [time-nuts] Sun Outage Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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.
[time-nuts] Sun Outage
The sun can have some effects on GPS signals, particularly when doing ultra-precisiony sorts of things. Version 4 of Lady Heather calculates the sun (and moon) positions (and moon phase) and can display them as part of the satellite position map (and analog watch display). This feature was added at the request of a few people that are/were investigating the effects of the sun on GPS signals. ___ 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] Sun Outage
Where is this Version 4 available? On 10/09/2014 01:28 PM, Mark Sims wrote: The sun can have some effects on GPS signals, particularly when doing ultra-precisiony sorts of things. Version 4 of Lady Heather calculates the sun (and moon) positions (and moon phase) and can display them as part of the satellite position map (and analog watch display). This feature was added at the request of a few people that are/were investigating the effects of the sun on GPS signals. ___ 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. -- Chuck Forsberg WA7KGX c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] Sun Outage
You pick up satellite TV with a parabolic dish that points at one spot in the sky where the geostationary satellite lives. A sun outage happens when the sun wanders into the focus and overloads the receiver with noise that drowns out the satellite signal (at least, it raises the noise floor enough that you can't receive the high bitrates needed for a TV picture). You pick up GPS with a whole-sky antenna that receives signals from the constantly-moving swarm of GPS satellites. It undoubtedly receives some noise from the sun, but the only factor in how much of that you get is the sun's elevation above the horizon. It's not really relevant whether the sun is aligned with a satellite or not. Even if it was, the satellite would be somewhere else a minute later. :) Andrew On Thu, Oct 9, 2014 at 1:40 PM, Bob Stewart b...@evoria.net wrote: Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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] Sun Outage
On 9 Oct 2014 22:17, Andrew Rodland and...@cleverdomain.org wrote: You pick up satellite TV with a parabolic dish that points at one spot in the sky where the geostationary satellite lives. A sun outage happens when the sun wanders into the focus and overloads the receiver with noise that drowns out the satellite signal (at least, it raises the noise floor enough that you can't receive the high bitrates needed for a TV picture). You pick up GPS with a whole-sky antenna that receives signals from the constantly-moving swarm of GPS satellites. It undoubtedly receives some noise from the sun, but the only factor in how much of that you get is the sun's elevation above the horizon. It's not really relevant whether the sun is aligned with a satellite or not. Even if it was, the satellite would be somewhere else a minute later. :) Andrew Also the much higher gain of the satellite antenna means if the Sun is in its beamwidth, a much larger increase in noise will occur. I would actually be concerned about the Sun heating (melting ??) the receiver, like I expect we have all done with a magnifying glass. The capture area of a dish is a lot more than any normal magnifying glass. Dave ___ 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] FE5440E Cesium parts wanted
I'm looking for the A12 18V power supply and A8 secondary 5 MHz OCXO modules for an attempt to resurrect my Cesium unit before it gets too heavy for me to wrestle with... Does anyone have a parts unit or junker that they might be able to supply these from please? Thanks, Dan ___ 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] Sun Outage
If you have an interest in trying to measure sun noise, you might like to have a look at the itty bitty radio telescope. (watch the line wrap) http://www.arrl.org/files/file/ETP/Radio%20Astronomy/Build%20a%20Homebrew%20Radio%20Telescope-QST-0609.pdf http://www.gb.nrao.edu/epo/ambassadors/ibtmanualshort.pdf http://www.stargazing.net/david/radio/itty_bitty_radio_telescope.html as a start. A google search will return more. cheers, Graham ve3gtc On 2014-10-09 14:23, paul swed wrote: Exactly geosyncs have sun outages as the sun aligns with the sat and your dish. GPS because the sats are distributed do not suffer from the effect. Regards Paul WB8TSL On Thu, Oct 9, 2014 at 2:04 PM, Mike Feher mfe...@eozinc.com wrote: Bob - I do not believe it has any effect. The DirecTV satellites are geostationary at about 22K miles. I used to experience the same phenomenon in the late 70's with my TVRO receiver at C band. GPS has some 36 or so satellites in a Medium Earth Orbit (MEO). Blockage, if it can even occur due to the nature of the receiving antenna, of a single one for a few minutes will have no discernible effect in my opinion. 73 - 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 [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 09, 2014 1:40 PM To: Time Nuts Subject: [time-nuts] Sun Outage Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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. ___ 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] Sun Outage
Hi Bob: The geostationary sats are in a 24 hour orbit. The orbit is also in the plane of the Earth's equator. Because of these two facts they appear stationary. Also because of that twice a year near equinox the Sun will be directly behind the sat and the C/N goes to pot so no signal. I have a mirror with masking tape reducing it's size to about 5/8 on a window sill that gets light at equinox and all through winter. I've marked the ceiling so I can just look up to see if the Sun is anywhere near the satellite. http://www.prc68.com/I/Sundial.shtml#SSB I can also tell when it's noon local time from this ceiling sundial. The orbit time for GPS sats is 12.0 sidereal hours and the plane of their orbits is angled 55 degrees from the equator so the Sun at most can be behind only one sat and then not for long, so you will not see any solar blockage, unless you are in a single satellite time only mode of operation and even they it would be a science experiment to detect the effect of the Sun. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Bob Stewart wrote: Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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] Sun Outage
Hi Dave: The small size of the Ku-band TV dish and that it's surface is covered with a flat type paint means there's little or no thermal heating of the receiver or feed. There were cases with the early C-band TVRO systems where they did melt the receiver. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Dr. David Kirkby (Kirkby Microwave Ltd) wrote: On 9 Oct 2014 22:17, Andrew Rodland and...@cleverdomain.org wrote: You pick up satellite TV with a parabolic dish that points at one spot in the sky where the geostationary satellite lives. A sun outage happens when the sun wanders into the focus and overloads the receiver with noise that drowns out the satellite signal (at least, it raises the noise floor enough that you can't receive the high bitrates needed for a TV picture). You pick up GPS with a whole-sky antenna that receives signals from the constantly-moving swarm of GPS satellites. It undoubtedly receives some noise from the sun, but the only factor in how much of that you get is the sun's elevation above the horizon. It's not really relevant whether the sun is aligned with a satellite or not. Even if it was, the satellite would be somewhere else a minute later. :) Andrew Also the much higher gain of the satellite antenna means if the Sun is in its beamwidth, a much larger increase in noise will occur. I would actually be concerned about the Sun heating (melting ??) the receiver, like I expect we have all done with a magnifying glass. The capture area of a dish is a lot more than any normal magnifying glass. Dave ___ 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] Sun Outage
On 9 Oct 2014 23:28, Brooke Clarke bro...@pacific.net wrote: Hi Dave: The small size of the Ku-band TV dish and that it's surface is covered with a flat type paint means there's little or no thermal heating of the receiver or feed. There were cases with the early C-band TVRO systems where they did melt the receiver. Reminds me of some idiot who designed a building in London. It had curved mirrors on it, angled towards the road. The result was the road, vehicles and shops were being burnt by the sun. It was all in the news here a year or two ago. ___ 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] Sun Outage
Hi Graham: Do you know if anyone has used a Ku-band receiver, like described in the paper, to look at Jupiter? The Radio Jove project is looking between 18 and 40 MHz. http://radiojove.gsfc.nasa.gov/ Have Fun, Brooke Clarke, N6GCE http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Graham wrote: If you have an interest in trying to measure sun noise, you might like to have a look at the itty bitty radio telescope. (watch the line wrap) http://www.arrl.org/files/file/ETP/Radio%20Astronomy/Build%20a%20Homebrew%20Radio%20Telescope-QST-0609.pdf http://www.gb.nrao.edu/epo/ambassadors/ibtmanualshort.pdf http://www.stargazing.net/david/radio/itty_bitty_radio_telescope.html as a start. A google search will return more. cheers, Graham ve3gtc On 2014-10-09 14:23, paul swed wrote: Exactly geosyncs have sun outages as the sun aligns with the sat and your dish. GPS because the sats are distributed do not suffer from the effect. Regards Paul WB8TSL On Thu, Oct 9, 2014 at 2:04 PM, Mike Feher mfe...@eozinc.com wrote: Bob - I do not believe it has any effect. The DirecTV satellites are geostationary at about 22K miles. I used to experience the same phenomenon in the late 70's with my TVRO receiver at C band. GPS has some 36 or so satellites in a Medium Earth Orbit (MEO). Blockage, if it can even occur due to the nature of the receiving antenna, of a single one for a few minutes will have no discernible effect in my opinion. 73 - 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 [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 09, 2014 1:40 PM To: Time Nuts Subject: [time-nuts] Sun Outage Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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. ___ 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] GPS jump
Folks, We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have noticed that the normal steady straight line (with standard daily noise) took a noticeable downward turn - on all 5 masers. Did anyone else who tracks H-masers notice this as well? Is it JPL making corrections? 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] GPS jump
Hello Jim, I am just a novice here - but, when you say noticeable, can you please tell us how noticeable? What is a small downturn vs. a noticeable one? I just put up an outdoor GPS antenna. If there is anything I can do to possibly help, please give me instructions. I do not have direct access to any Hydrogen masers at the moment. Thanks, John W. On Thu, Oct 9, 2014 at 4:43 PM, Jim Palfreyman jim77...@gmail.com wrote: Folks, We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have noticed that the normal steady straight line (with standard daily noise) took a noticeable downward turn - on all 5 masers. Did anyone else who tracks H-masers notice this as well? Is it JPL making corrections? 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] Sun Outage
Hello all... Not all satellite TV antennas are parabolic. A typical C-Band antenna is parabolic and aligned for one satellite. But, that could change if the feed was modified to receive multi-satellites, while the shape of the reflector remained parabolic. Or the antenna could be an off-center fed elliptical version. Satellite antennas for Dish and DirecTV are not parabolic, but they are off-center fed and either circular or elliptical. The elliptical version usually supports a feed that will cover multiple satellites. C-Band satellites in the U.S. Domestic arc are normally spaced two degrees apart, with some at 4 degrees spacing. DBS (Direct Broadcast Service) i.e. Dish and DirecTV, satellites are spaced 9 degrees apart. Clusters of satellites can be parked at one location to supply additional capacity for spot beam coverage. DBS service is located in the Ku-Band. More info at: https://docs.google.com/presentation/d/1eNMYmcNIxRFpK1PY0GqbvOfvNfzRra4fHxs8 A4hSy7o/preview#slide=id.p18 73 Don W4WJ In a message dated 10/9/2014 4:17:20 P.M. Central Daylight Time, and...@cleverdomain.org writes: You pick up satellite TV with a parabolic dish that points at one spot in the sky where the geostationary satellite lives. A sun outage happens when the sun wanders into the focus and overloads the receiver with noise that drowns out the satellite signal (at least, it raises the noise floor enough that you can't receive the high bitrates needed for a TV picture). You pick up GPS with a whole-sky antenna that receives signals from the constantly-moving swarm of GPS satellites. It undoubtedly receives some noise from the sun, but the only factor in how much of that you get is the sun's elevation above the horizon. It's not really relevant whether the sun is aligned with a satellite or not. Even if it was, the satellite would be somewhere else a minute later. :) Andrew On Thu, Oct 9, 2014 at 1:40 PM, Bob Stewart b...@evoria.net wrote: Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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] Sun Outage
Hi Don: It's my understanding that all satellite dishes have a parabolic curve which focuses the signal on the feed. The C-band dish has a round outline and the feed is located along the dish center line. Most commercial Ku-band antennas have a parabolic curve, but have a elliptical or orange peal outline. These are off center fed so that the feed does not shadow the antenna like it did on the C-band dishes. This is the same problem that the vast majority of reflecting astronomical telescopes have, i.e. the secondary mirror area needs to be subtracted from the primary mirror area to get the effective primary mirror area. A very practical result of that difference is that a C-band dish has it's main beam along the dish center line, but a Ku-band dish does not. http://www.prc68.com/I/Images/SB_angw.jpg - showing the beam realtive to the dish and beam hitting gutter. Better when dish mounted on roof: http://www.prc68.com/I/SBvsat.shtml But the construction of the older dish was better than the newer/cheaper dish. The Free To Air (FTA) Ku-band dishes also have a parabolic curve round outline, but they are offset fed, see: http://www.prc68.com/I/FTA.shtml Have Fun, Brooke Clarke, N6GCE http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Don Murray via time-nuts wrote: Hello all... Not all satellite TV antennas are parabolic. A typical C-Band antenna is parabolic and aligned for one satellite. But, that could change if the feed was modified to receive multi-satellites, while the shape of the reflector remained parabolic. Or the antenna could be an off-center fed elliptical version. Satellite antennas for Dish and DirecTV are not parabolic, but they are off-center fed and either circular or elliptical. The elliptical version usually supports a feed that will cover multiple satellites. C-Band satellites in the U.S. Domestic arc are normally spaced two degrees apart, with some at 4 degrees spacing. DBS (Direct Broadcast Service) i.e. Dish and DirecTV, satellites are spaced 9 degrees apart. Clusters of satellites can be parked at one location to supply additional capacity for spot beam coverage. DBS service is located in the Ku-Band. More info at: https://docs.google.com/presentation/d/1eNMYmcNIxRFpK1PY0GqbvOfvNfzRra4fHxs8 A4hSy7o/preview#slide=id.p18 73 Don W4WJ In a message dated 10/9/2014 4:17:20 P.M. Central Daylight Time, and...@cleverdomain.org writes: You pick up satellite TV with a parabolic dish that points at one spot in the sky where the geostationary satellite lives. A sun outage happens when the sun wanders into the focus and overloads the receiver with noise that drowns out the satellite signal (at least, it raises the noise floor enough that you can't receive the high bitrates needed for a TV picture). You pick up GPS with a whole-sky antenna that receives signals from the constantly-moving swarm of GPS satellites. It undoubtedly receives some noise from the sun, but the only factor in how much of that you get is the sun's elevation above the horizon. It's not really relevant whether the sun is aligned with a satellite or not. Even if it was, the satellite would be somewhere else a minute later. :) Andrew On Thu, Oct 9, 2014 at 1:40 PM, Bob Stewart b...@evoria.net wrote: Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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. ___ 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] Digital Mixing with a BeagleBone Black and D Flip Flop
Simon, I breadboaded a set-up in March using 74AC74's and two 10 MHz Micro Crystal oscillators (5V square wave), one as the coherent source and one as the 10Hz offset clock. I had no glitch filtering as described in the article you cite (CERN's White Rabbit Project, sub nanosecond timing over ethernet) but found the positive zero crossing was very clean. The negative crossing not so much; no idea why one edge was clean and the other not. To ensure I only measured the rising clock edge and not the noise on the falling clock, I programmed ATiny's (digital 555?) to arm the D-flops only after a period of continuous low states. In any event, the lash up, as measure by a 5370, produced a clean linear noise floor of 8e-12 at 1s. I regret to note that's very slightly better than my results from the Bill Riley DMTD device. That's an indictment of my analog building skills, not his design. It's also nicely below a 5370 on it's own and needs only a simple 10 MHz counter for output. The zero crossing detectors for sine wave oscillator input will perhaps be more critical. This was encouraging enough that I thought I'd try to build an FPGA version of the same. The DDMTD is temporarily on back burner while I try to get a four channel 1ns resolution time tagger running on the FPGA to use with the DMTD. Almost there. I look forward to hearing your results with the BBB; keep us posted. Bob Darby On 10/9/2014 1:34 AM, Andrew Rodland wrote: Simon, This is a fantastic idea and I have every intention of trying to replicate it at home with tools on hand. Thanks for sharing, and I hope you can show off some results. On Wed, Oct 8, 2014 at 1:09 PM, Simon Marsh subscripti...@burble.com wrote: I've been a lurker on time-nuts for a while, most of the discussion being way over my head, but I thought there may be interest in some proof of concept code I've written for simple digital hetrodyne mixing using just a BeagleBone Black and an external dual D Flip Flop. The idea is based on the following article which describes creating a digital DMTD with an FPGA for clocks @ 125mhz: http://www.ee.ucl.ac.uk/lcs/previous/LCS2011/LCS1136.pdf My setup follows the same principle, but scaled down to 10mhz to make it as simple as possible (and not require an FPGA). The hardware side is just a 74AC74 dual flip flop to sample the input clocks being tested. Instead of having a helper PLL for the mixer frequency, I simply have a 3rd, de-tuned oscillator. The output from the two flip-flops together with the mixer clock are fed to the BBB. On the BBB, the approach is to do as little as possible in real time using a PRU core, and then post-process on the ARM core afterwards. The BBB PRU has a 16-bit, asynchronous, parallel, capture mode, where 16 GPIO pins can be latched based on an external clock (described in section 4.4.1.2.3.2 of the TRM for those interested). In this case, the external clock is the mixer oscillator. All the PRU needs to do is wait for the sample to take place, read the GPIOs and store the results in main memory. The PRU is plenty fast enough to capture samples @10mhz and, in theory at least, each PRU could sample up to 16 clocks simultaneously (depending on whether the relevant GPIO pins were free). Once the sampling is complete, the ARM core can process the results in its own time, and this includes any more complicated algorithms for de-glitching etc The theoretical minimum time resolution depends on the beat frequency and is described in the article, for example with a beat frequency of 50 hz the minimum resolution is 50 / (1000 - 50)*1000 = ~5E-13. In practice the available accuracy is determined by the stability of the mixer clock and noise of the setup. The impact of this noise is described in the article as glitching and there are some suggested ways for processing this out. I'm trying this on an open bench, with basic oscillators, using pluggable breadboard and lots of hanging wires, I'm not at risk of getting near the theoretical limit quite yet :) Note that the BBB itself has no impact on the accuracy or noise of the raw data. Once the input is latched at the flip-flop, the only bit of critical timing required is to ensure that samples can be captured fast enough and that the flip-flop state is captured when it is stable (i.e. not transitioning). I make no excuses that this is very simplistic, and there are many, many ways that it can (should!) be improved. For me the next steps will probably be: 1) Get off the breadboard and focus a bit more on getting the signals to the flip-flop with a 'reasonable' amount of noise. 2) Improve the PRU code so that it stores transitions and not just the raw samples, this would offload a significant bit of work from the ARM core, save a load of memory and allow continuous streaming of data (instead of the current one shot approach). 3) Experimentation with different algorithms for processing the data on the ARM. I don't think anyone
Re: [time-nuts] GPS jump
Hi GPS is steered by the Air Force last time I checked. A really good place to check is the NIST Time and Frequency pages that show both real time and historical data for each GPS sat compared to NIST time: http://www.nist.gov/pml/div688/grp40/gpsarchive.cfm Hopefully it’s accessible via that link from a variety of locations. Since the NIST data is independent of the steering (two different outfits involved) it should not be vulnerable to a “our ground segment broke and we steered everything to match” sort of error. Bob On Oct 9, 2014, at 7:43 PM, Jim Palfreyman jim77...@gmail.com wrote: Folks, We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have noticed that the normal steady straight line (with standard daily noise) took a noticeable downward turn - on all 5 masers. Did anyone else who tracks H-masers notice this as well? Is it JPL making corrections? 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] Sun Outage
Hi Brooke... You are correct. My semantics were confusing! The offset feed certainly has an advantage because of no shadowing, but a lot of commercial Ku-Band antennas are complete parabolic reflectors with a sub-reflector and cassegrain feed. There obviously is some loss because of the sub reflector, but these are larger antennas and the loss is acceptable. TNX for you feedback Brooke! 73 Don W4WJ In a message dated 10/9/2014 7:26:55 P.M. Central Daylight Time, bro...@pacific.net writes: Hi Don: It's my understanding that all satellite dishes have a parabolic curve which focuses the signal on the feed. The C-band dish has a round outline and the feed is located along the dish center line. Most commercial Ku-band antennas have a parabolic curve, but have a elliptical or orange peal outline. These are off center fed so that the feed does not shadow the antenna like it did on the C-band dishes. This is the same problem that the vast majority of reflecting astronomical telescopes have, i.e. the secondary mirror area needs to be subtracted from the primary mirror area to get the effective primary mirror area. A very practical result of that difference is that a C-band dish has it's main beam along the dish center line, but a Ku-band dish does not. http://www.prc68.com/I/Images/SB_angw.jpg - showing the beam realtive to the dish and beam hitting gutter. Better when dish mounted on roof: http://www.prc68.com/I/SBvsat.shtml But the construction of the older dish was better than the newer/cheaper dish. The Free To Air (FTA) Ku-band dishes also have a parabolic curve round outline, but they are offset fed, see: http://www.prc68.com/I/FTA.shtml Have Fun, Brooke Clarke, N6GCE http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Don Murray via time-nuts wrote: Hello all... Not all satellite TV antennas are parabolic. A typical C-Band antenna is parabolic and aligned for one satellite. But, that could change if the feed was modified to receive multi-satellites, while the shape of the reflector remained parabolic. Or the antenna could be an off-center fed elliptical version. Satellite antennas for Dish and DirecTV are not parabolic, but they are off-center fed and either circular or elliptical. The elliptical version usually supports a feed that will cover multiple satellites. C-Band satellites in the U.S. Domestic arc are normally spaced two degrees apart, with some at 4 degrees spacing. DBS (Direct Broadcast Service) i.e. Dish and DirecTV, satellites are spaced 9 degrees apart. Clusters of satellites can be parked at one location to supply additional capacity for spot beam coverage. DBS service is located in the Ku-Band. More info at: https://docs.google.com/presentation/d/1eNMYmcNIxRFpK1PY0GqbvOfvNfzRra4fHxs8 A4hSy7o/preview#slide=id.p18 73 Don W4WJ In a message dated 10/9/2014 4:17:20 P.M. Central Daylight Time, and...@cleverdomain.org writes: You pick up satellite TV with a parabolic dish that points at one spot in the sky where the geostationary satellite lives. A sun outage happens when the sun wanders into the focus and overloads the receiver with noise that drowns out the satellite signal (at least, it raises the noise floor enough that you can't receive the high bitrates needed for a TV picture). You pick up GPS with a whole-sky antenna that receives signals from the constantly-moving swarm of GPS satellites. It undoubtedly receives some noise from the sun, but the only factor in how much of that you get is the sun's elevation above the horizon. It's not really relevant whether the sun is aligned with a satellite or not. Even if it was, the satellite would be somewhere else a minute later. :) Andrew On Thu, Oct 9, 2014 at 1:40 PM, Bob Stewart b...@evoria.net wrote: Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun aligned with the satellite and my dish. So I was wondering what kind of effect this has on the GPS system and especially timing receivers. 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. ___ time-nuts mailing list --
Re: [time-nuts] Sun Outage
On Thu, 09 Oct 2014 18:14:55 -0400 Graham planoph...@aei.ca wrote: If you have an interest in trying to measure sun noise, you might like to have a look at the itty bitty radio telescope. (watch the line wrap) http://www.arrl.org/files/file/ETP/Radio%20Astronomy/Build%20a%20Homebrew%20Radio%20Telescope-QST-0609.pdf http://www.gb.nrao.edu/epo/ambassadors/ibtmanualshort.pdf http://www.stargazing.net/david/radio/itty_bitty_radio_telescope.html as a start. A google search will return more. cheers, Graham ve3gtc As an alternative, you might consider the Drake commercial satellite receivers. I've bought a few of these off of Ebay for about $20 each. These show up at recyclers. Every one I got worked. They have just been sitting in rack until I suppose the service wasn't needed. These commercial receivers have analog meters that you could tap. I've bough the ESR 1255. I have manuals for the 1245, 1252, 1255, 1260, and 1450 if you can't find them online. But probably the 1252 or 1255 is what would work best in this application. ___ 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] GPS jump
Le 10 oct. 2014 à 03:09, Bob Camp a écrit : Hi GPS is steered by the Air Force last time I checked. A really good place to check is the NIST Time and Frequency pages that show both real time and historical data for each GPS sat compared to NIST time: http://www.nist.gov/pml/div688/grp40/gpsarchive.cfm Hopefully it’s accessible via that link from a variety of locations. Since the NIST data is independent of the steering (two different outfits involved) it should not be vulnerable to a “our ground segment broke and we steered everything to match” sort of error. Bob On Oct 9, 2014, at 7:43 PM, Jim Palfreyman jim77...@gmail.com wrote: Folks, We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have noticed that the normal steady straight line (with standard daily noise) took a noticeable downward turn - on all 5 masers. I remember Jim reported a similar issue back in october last year: On 2013-10-03 05:33, Jim Palfreyman wrote: Noticed an above average bump in our H-Maser vs GPS graphs - from sites all over Australia. Recent coronal mass ejection or US government shutdown not updating GPS? Anyone else seen it? drop out gap between about 04.21-04.26 UTC? clockstats.20131003: 56568 15684.876 127.127.20.4 $GPRMC 042124 A ... 56568 16004.862 127.127.20.4 $GPRMC 042644 A ... peerstats.20131003: 56568 15684.876 127.127.20.4 961a -0.02270 ... 0.05344 56568 16004.862 127.127.20.4 961a -0.13150 ... 0.15721 loopstats.20131003: 56568 15684.876 -0.02270 0.899 0.07071 0.70 4 56568 16004.862 -0.13150 0.898 0.08830 0.000114 4 That dates are close enough to make you wonder if it is not part of some cycle. Did anyone else who tracks H-masers notice this as well? Is it JPL making corrections? 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. ___ 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.
