[time-nuts] SCPI Command Set for FURUNO GT-80
Does anyone have a pointer to the command set for a Furuno GT-80 please? 73, Steve -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ 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 Jamming Interference in London, February next year
For readers in England, NPL is hosting an event entitled GPS Jamming Interference - A Clear and Present Danger at their Teddington (West London) headquarters on the 23rd of February 2010. See their web page at http://lat.globalwatchonline.com/epicentric_portal/site/lat/events/2010/gps-jamming-interference/?mode=0 Regards, Peter Vince ___ 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] Amatuer Radio Information
Greetings: I have noticed that some of you have call signs for Amateur Radio and I decided that I would like to get into that again. Several years ago I was looking into it and was given some modified military surplus radio equipment, one such item was a transceiver. Unfortunately, when we moved from the location that I lived in at that time, we could not take the radio equipment with us because it was vacuum tube based and very heavy and the moving company of course was charging by the pound. I discovered where I can take my exam locally and would like to study up a little as it has been years. I understand that I no longer have to do Morse code as part of it, but still would like to find resources on study materials and practice tests. As far as equipment is concerned, I am on a tight budget and so it will likely be eBay and Craigslist, but I am not sure what I need these days. I have computers a- plenty and basically can use advice on what kind of transceiver to get, what are the best brands and what I need for an antenna - I live in an apartment and want to do this with a base-station radio setup as opposed to a mobile. I need an antenna that would be the least obtrusive and not mounted in a permanent fashion to the building. I also need information on what kind of lightning protection and etc would be good. Thanks - I know this is off topic but I do plan to keep perfect time with my station as well J My real email address appears below, so if someone wants to offer help off list I welcome someone to write me and of course if you live locally to Lawrence, I would love to meet in person and exchange ideas etc. J. Mike Needham iain_ni...@att.net Lawrence, Kansas USA ___ 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] Amatuer Radio Information
Hi Mike, I'll reply to the list because others will probably give you a similar reply. First of all, thank you for your interest in amateur radio. It's often described as a hobby with lots of sub-hobbies, so chances are you can find something that will pique your interest for a long time. Don't sweat the tests. Anyone on this list likely already possesses the technical know-how to pass it. Even if you don't, it's mostly ohm's law and a few regulations. The ARRL is a national organization that supports ham radio. They have a section on their web site devoted to new hams. You should take a look at the articles here: http://www.arrl.org/newham/, especially the choosing a radio one. After you read it, you'll see why we can't simply recommend a single radio :-) Probably the single best source of support for ham radio is your local radio club. There, you will find a network of people who have a wide array of interests in the hobby and would love to share their interest with you. Many clubs offer testing and even classes if you want to go that route. Most importantly, there's usually someone in the club who has a used radio for sale that you can get started with. I love buying used equipment because it holds its value. Also, if you purchase from an individual, you can go try it out in their shack before you take it home. That way you know it works. The ARRL web site has a listing of local clubs and testing sites. Likewise, I would recommend you stay away from the popular Internet ham radio chat boards. While there are some good guys on there, there are also a number of cretins who just want to show how smart they think they are. Many of them dispense faulty advice, are rude to newcomers, and are generally poor ambassadors of the hobby. This is in stark contrast to the people I have met on the air and in the local clubs, most of whom are open, friendly, and supportive. If you have any more questions, please contact me off-list. Thanks and welcome aboard! 73 de AJ4MJ On Wed, Nov 25, 2009 at 10:37 AM, J. Mike Needham iain_ni...@att.netwrote: Greetings: I have noticed that some of you have call signs for Amateur Radio and I decided that I would like to get into that again. Several years ago I was looking into it and was given some modified military surplus radio equipment, one such item was a transceiver. Unfortunately, when we moved from the location that I lived in at that time, we could not take the radio equipment with us because it was vacuum tube based and very heavy and the moving company of course was charging by the pound. I discovered where I can take my exam locally and would like to study up a little as it has been years. I understand that I no longer have to do Morse code as part of it, but still would like to find resources on study materials and practice tests. As far as equipment is concerned, I am on a tight budget and so it will likely be eBay and Craigslist, but I am not sure what I need these days. I have computers a- plenty and basically can use advice on what kind of transceiver to get, what are the best brands and what I need for an antenna - I live in an apartment and want to do this with a base-station radio setup as opposed to a mobile. I need an antenna that would be the least obtrusive and not mounted in a permanent fashion to the building. I also need information on what kind of lightning protection and etc would be good. Thanks - I know this is off topic but I do plan to keep perfect time with my station as well J My real email address appears below, so if someone wants to offer help off list I welcome someone to write me and of course if you live locally to Lawrence, I would love to meet in person and exchange ideas etc. J. Mike Needham iain_ni...@att.net Lawrence, Kansas USA ___ 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] Amatuer Radio Information
Hi J, (and the rest. I'm answering here because I figure others might be in the same position) There are several ways to prepare for the tests. The way a lot of people recommend is to get a study guide and basically study. Read, learn, maybe take a practice test, and get the license. Once the license is in hand, get a radio and get on the air. That's all fine and well, but I don't think it's the best way to go. I recommend taking the easy approach which consists of simply memorizing the correct answer to the questions on the test (all of them and their answers are made available by the FCC and appear in all the study guides). Granted, you don't learn much this way, but that's not an issue as you'll learn quickly as you do. You can find practice tests here: http://www.eham.net/exams/ There used to be great practice tests at qrz.com but I can't seem to find them today. Odd. If you'd rather go with a study guide to start off with, I recommend getting a highlighter and highlight the letter (A, B, C, D, whatever) of the correct answer. Never look at the incorrect answers, only the correct ones. Read them, a few times along with the question and you'll easily pass the test because when you see an answer on the test that you don't recognize, it's obviously not the right answer! While you are studying, be it from a book or just taking practice tests and memorizing answers, it's a good time to research radios. I think it's a good idea to get the radio before the license because it not only gives you encouragement to get the license (you can't transmit without a license), you'll get experience with procedures on the airwaves that the study guides simply don't cover. Doing this will make you sound a lot better than if you were to just jump on without having ever listened. Hams generally don't like it if you sound like you've been on Children's Band, however they are generally forgiving. Take the time to listen for a while but don't hesitate to jump into a conversation if you feel you can contribute. You can get a brand new 2 meter band HT or Handi Talkie for under $150 delivered. I have one for various uses but it hardly gets used because 2 meter is completely dead here in New Mexico. It's better if you find out about this stuff by talking to other hams near you. Before I moved to NM, I was in Philadelphia and 2meter was very popular so the $150 was justified at the time but I wouldn't do it again living here. Out here I'm almost exclusively on HF bands using the modern digital communications modes like PSK31. The first license (Technician) will not get you on the HF bands unless you count 6 meter (50MHz) as HF. In 10 years I haven't heard a soul on 6 so I don't really even bother with listening anymore. To get on HF, the General license will get you 95% of what Extra will get you. I went for Extra for two reasons. The first was just for fun. The other was so that it's harder to make mistakes. If I can hear them on the airwaves, I know I can work them without breaking FCC regs (there are Extra Only portions of the bands that I couldn't use with General). Find a local club (http://www.w0uk.net/ appears to be near you) and talk to people and ask questions. They will have the scoop on the local tests, hamfests, and will have experience working the bands. Beware though, ask 5 hams for recommendations on anything and you'll get 6 different answers -if not more. Feel free to contact me directly if you have any questions at all. Bob, N3XKB (Extra and ARRL VE) On Wed, Nov 25, 2009 at 8:37 AM, J. Mike Needham iain_ni...@att.net wrote: Greetings: I have noticed that some of you have call signs for Amateur Radio and I decided that I would like to get into that again. Several years ago I was looking into it and was given some modified military surplus radio equipment, one such item was a transceiver. Unfortunately, when we moved from the location that I lived in at that time, we could not take the radio equipment with us because it was vacuum tube based and very heavy and the moving company of course was charging by the pound. I discovered where I can take my exam locally and would like to study up a little as it has been years. I understand that I no longer have to do Morse code as part of it, but still would like to find resources on study materials and practice tests. As far as equipment is concerned, I am on a tight budget and so it will likely be eBay and Craigslist, but I am not sure what I need these days. I have computers a- plenty and basically can use advice on what kind of transceiver to get, what are the best brands and what I need for an antenna - I live in an apartment and want to do this with a base-station radio setup as opposed to a mobile. I need an antenna that would be the least obtrusive and not mounted in a permanent fashion to the building. I also need information on what kind of lightning protection and etc would be good.
Re: [time-nuts] Amatuer Radio Information
On 11/25/09, Robert Darlington rdarling...@gmail.com wrote: Out here I'm almost exclusively on HF bands using the modern digital communications modes like PSK31. The first license (Technician) will not get you on the HF bands unless you count 6 meter (50MHz) as HF. well, 6m isn't anything like HF (imho). In 10 years I haven't heard a soul on 6 so I don't really even bother with listening anymore. To get on HF, the General license will get you 95% of what Extra wow... I think I worked something like 90 dxcc countries with modest setup in less than three years (but that was in 2001-2003). For sure I worked all europe and all african active countries with 10W into a homemade vertical J-pole antenna back in the best years of the last solar cycle. Now with a medium-sized beam in the right months I can work from USA to Japan (with 100W only). I see from the cluster spots that USA and all american continent are also much more blessed with 6m propagation all the year with respect to europe in this very low cycle minimum. Sorry for the extreme off-topic, but it's just to witness that VHF isn't dead and many of us don't even have HF antennas and still enjoy the activity in the VHF challenging bands all the year. Amateur radio has so many different aspect that any technical person can find always new challenging aspects to explore. No band is dead if someone has the right interest in it! best 73 F ___ 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] LORAN rescued by Congress?
If I read it right, Congress in the USA has overturned the President's FY2010 statement to keep LORAN going as a backup to GPS. See: http://pnt.gov/policy/legislation/bills.shtml#loran Regards, Peter Vince ___ 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] Thunderbolt reception problems
Warren, Thanks for the Tbolt tips. The power supply was a good linear supply so I doubt that was causing what I see. The room temp was cycling a degree, maybe two, I did sometime see some quick shifts that were not coincident with temperature but they were all less than 10 nS. The largest swings always followed temperature excursions. Even after putting it in a box and lowering the temp. drift to fractions of a degree, I would see swings if as much as 30 nS in 5 minutes. I thought that this was just too much to fool with and decided to use it as a reference for a 900 MHz ham repeater. It will be interesting to see how it does in a room with no heat or air conditioning. I hope to get on next week. I have another one and may, at some time try putting a double oven oscillator to see how it does. I thought about trying an LPRO but I think the Tbolt would just make it worse rather than better. ___ 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] LORAN rescued by Congress?
- Original Message From: Peter Vince pvi...@theiet.org To: time-nuts@febo.com Sent: Wed, November 25, 2009 11:21:36 AM Subject: [time-nuts] LORAN rescued by Congress? If I read it right, Congress in the USA has overturned the President's FY2010 statement to keep LORAN going as a backup to GPS. See: http://pnt.gov/policy/legislation/bills.shtml#loran Regards, Peter Vince ___ 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] LORAN rescued by Congress?
I read it and came to the opposite conclusion, the only bills that count are ones signed by the president which was the bill that allowed termination. Stanley - Original Message From: Peter Vince pvi...@theiet.org To: time-nuts@febo.com Sent: Wed, November 25, 2009 11:21:36 AM Subject: [time-nuts] LORAN rescued by Congress? If I read it right, Congress in the USA has overturned the President's FY statement to keep LORAN going as a backup to GPS. See: http://pnt.gov/policy/legislation/bills.shtml#loran Regards, Peter Vince ___ 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] Amatuer Radio Information
Sorry for the extreme off-topic, but it's just to witness that VHF isn't dead and many of us don't even have HF antennas and still enjoy the activity in the VHF challenging bands all the year. Yeap , you're right... I'm only active from 1296MHz and above, and I could have activity (both building/setting-up and operating) orders of magnitude higher than I could possibly handle. My 2cents to help changing the general misconception that above HF there is very little do do... On the contrary... many of us don't even have HF antennas Hummm... What is HF ??? ;-) :-) Luis Cupido ct1dmk. http://w3ref.cfn.ist.utl.pt/cupido/ . Op... this one was very off-topic, my apologies. Although I posted it at a very precise time ;-) francesco messineo wrote: On 11/25/09, Robert Darlington rdarling...@gmail.com wrote: Out here I'm almost exclusively on HF bands using the modern digital communications modes like PSK31. The first license (Technician) will not get you on the HF bands unless you count 6 meter (50MHz) as HF. well, 6m isn't anything like HF (imho). In 10 years I haven't heard a soul on 6 so I don't really even bother with listening anymore. To get on HF, the General license will get you 95% of what Extra wow... I think I worked something like 90 dxcc countries with modest setup in less than three years (but that was in 2001-2003). For sure I worked all europe and all african active countries with 10W into a homemade vertical J-pole antenna back in the best years of the last solar cycle. Now with a medium-sized beam in the right months I can work from USA to Japan (with 100W only). I see from the cluster spots that USA and all american continent are also much more blessed with 6m propagation all the year with respect to europe in this very low cycle minimum. Sorry for the extreme off-topic, but it's just to witness that VHF isn't dead and many of us don't even have HF antennas and still enjoy the activity in the VHF challenging bands all the year. Amateur radio has so many different aspect that any technical person can find always new challenging aspects to explore. No band is dead if someone has the right interest in it! best 73 F ___ 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] LORAN rescued by Congress?
My read is what is approved are the funds to carry it to the Jan 4 2010 termination date. A years ops are 4 X $36M. Sure hope someone else can say I am reading it wrong. But I had seen this and have been looking for anything that would have allowed a different interpretation. Regards On Wed, Nov 25, 2009 at 12:21 PM, Peter Vince pvi...@theiet.org wrote: If I read it right, Congress in the USA has overturned the President's FY2010 statement to keep LORAN going as a backup to GPS. See: http://pnt.gov/policy/legislation/bills.shtml#loran Regards, Peter Vince ___ 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] NMEA Time
Hi guys, has anyone used a program called NMEA Time? Has this been discussed here before? _http://www.visualgps.net/NMEATime/Download/Download.html_ (http://www.visualgps.net/NMEATime/Download/Download.html) It is supposed to generate IRIG-B on the Audio output, to provide an SNTP server, and various other time support via NMEA input, and via a 1PPS signal on the DSR/CTS port pins. Has anyone checked how accurate the SNTP server time-stamping is when using the RS-232 1PPS input? Thanks, Said ___ 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] NMEA Time
Hi Said, Yes it does generate IRIG B (modulated AF), I was recommended it to test a reader and it worked fine. You can download a 30 day trial for free. The website lists the limitations on the IRIG output. I didn't read them too closely as they didn't affect my application. Robert G8RPI. --- On Wed, 25/11/09, saidj...@aol.com saidj...@aol.com wrote: From: saidj...@aol.com saidj...@aol.com Subject: [time-nuts] NMEA Time To: time-nuts@febo.com Date: Wednesday, 25 November, 2009, 19:03 Hi guys, has anyone used a program called NMEA Time? Has this been discussed here before? _http://www.visualgps.net/NMEATime/Download/Download.html_ (http://www.visualgps.net/NMEATime/Download/Download.html) It is supposed to generate IRIG-B on the Audio output, to provide an SNTP server, and various other time support via NMEA input, and via a 1PPS signal on the DSR/CTS port pins. Has anyone checked how accurate the SNTP server time-stamping is when using the RS-232 1PPS input? Thanks, Said ___ 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] NMEA Time
Indeed I do use it on occasion a good program. It does gen IRIGB that my decoders read. I really use it just as a gen and do not have it hooked up to GPS or anything else On Wed, Nov 25, 2009 at 2:03 PM, saidj...@aol.com wrote: Hi guys, has anyone used a program called NMEA Time? Has this been discussed here before? _http://www.visualgps.net/NMEATime/Download/Download.html_ (http://www.visualgps.net/NMEATime/Download/Download.html) It is supposed to generate IRIG-B on the Audio output, to provide an SNTP server, and various other time support via NMEA input, and via a 1PPS signal on the DSR/CTS port pins. Has anyone checked how accurate the SNTP server time-stamping is when using the RS-232 1PPS input? Thanks, Said ___ 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] NMEA Time
Hi Robert, thanks for the info. I am wondering how accurate their SNTP server with 1PPS RS-232 input is. Not sure how one would test that without specialized equipment.. bye, Said In a message dated 11/25/2009 11:26:45 Pacific Standard Time, robert8...@yahoo.co.uk writes: Hi Said, Yes it does generate IRIG B (modulated AF), I was recommended it to test a reader and it worked fine. You can download a 30 day trial for free. The website lists the limitations on the IRIG output. I didn't read them too closely as they didn't affect my application. Robert G8RPI. ___ 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] Thunderbolt reception problems
John Thanks, that puts things a bit more in perspective. Sometimes One persons 'A lot' is another persons 'almost Great'. 5 min = 300 sec As much as 30 ns / 300 sec = 0.1ns /sec = less than 1e-10 freq shift A lot of NON broken things can cause that kind of small drift. With under 1e-10 shifts over 5 minutes, see below for some addition comments. ws - Original Message - From: John Green wpxs...@gmail.com To: time-nuts@febo.com Sent: Wednesday, November 25, 2009 9:47 AM Subject: Re: [time-nuts] Thunderbolt reception problems Warren, Thanks for the Tbolt tips. The power supply was a good linear supply so I doubt that was causing what I see. ws) Make sure it is not line sensitive, OR Temperature sensitive. A few mv change on the +12 V could cause that kind of error. Plug the PS into a variac and blow a hair driver at it to make sure that + - 15 % line change 15+ deg does not effect the Tbolt over the 5 min time span. ** The room temp was cycling a degree, maybe two. ws) 1 deg F can cause a 1e-10 freq shift, More important is how fast it is changing. Keeping the changes down to about 1 deg C per hr AT The Tbolt sensor is a conservative overkill that will keep temp from being an issue. ** I did sometime see some quick shifts that were not coincident with temperature but they were all less than 10 nS. ws) This Sounds like the typical Tbolt satellite switching problem. Solution is one or all of the following: Better signal or antenna view, better Position setting, lower AMU, Higher TC, higher elevation setting. The problem is that although these small fast phase jumps do not effect the Peak Phase much, They can cause a great deal of short term Freq noise. ** The largest swings always followed temperature excursions. Even after putting it in a box and lowering the temp. drift to fractions of a degree, I would see swings if as much as 30 nS in 5 minutes. ws) When you first put the Tbolt in a new environment (a box) it will take a couple hours for it to adjust to its new environment. After That, the important thing is what kind of temp change per time does the Tbolt see. Unfortunately, due to the two different kind of sensors used in Tbolts, (one type with high resolution, one is low resolution) this may not always be easy to see. One solution that gives you less phase shift error with 'quick' temp change is to lower the TC, The compromise is Less PP pahse error but you get more ADEV noise at 1 and 10 second tau. With slow changes at 'a fraction of a degree' (a fraction is 1/10 F or less), NOT likely it is the Tbolt drfting unless yours does not have a working Oven Osc at all. Check the current draw of the +12 volts with changing temp to see. More likely it is the Power supply changing IF you are holding the TBOLT constant while the room is changing. OR ANY of your other test equipment that is outside the BOX, and subject ot the quick temp change. ** I thought that this was just too much to fool with and decided to use it as a reference for a 900 MHz ham repeater. It will be interesting to see how it does in a room with no heat or air conditioning. I hope to get on next week. I have another one and may, at some time try putting a double oven oscillator to see how it does. I thought about trying an LPRO but I think the Tbolt would just make it worse rather than better. ws) There are easier ways to get the performance of a double oven Osc without the cost and trouble ... John Green said: mine got a lot worse with TC set to 500 sec. Depends if that was Short term Osc Freq noise or long term Phase drift? Short answer: A TC of 500 can causes a LOT more (x10 +) long term Phase shift error if the temp is changing, especially when the Dac_Gain and Damping are not also set correctly. Here comes those darn Tbolt setting trade offs again. First point is: If you are a battery backed cell site or the average Ham that just wants to know that the in house freq reference is within 1e-9 (1ns drift per second) the default Tbolts settings are fine and make an OK plug and play unit. On the other hand if you are a NUT would like 10 ns per day (1e-13 freq) then the factory defaults are not so good (Said). Another major trade off is if you want the best 1 sec ADEV numbers OR the lowest long term Phase errors. Takes different settings. Using the TC and Damping settings, different trade offs or compromises can be made. BUT until the Dac_Gain is set correctly (which the default setting is NOT), their proper setting And interaction is just a shot in the dark. Dac_gain is the sensitivity of the OXCO EFC input in Hz per Volt. Basic way to find the correct value is to disable the tracking, then output a + and - 0.1 volt Dac difference from its nominal tracking value using Tboltmon S/W, Average the measured + - HZ freq change of the 10 MHZ, multiply by 10, and update the Dac_Gain AND SAVE (sign is
Re: [time-nuts] NMEA Time
I've used NMEA time on all my windows computers for more than 5 years. I have not checked the accuracy, but on my version, the update rate can be set. The program is very stable, and has not caused a problem with either W2K or newer version. There's also a neat screensaver... Don saidj...@aol.com Hi guys, has anyone used a program called NMEA Time? Has this been discussed here before? _http://www.visualgps.net/NMEATime/Download/Download.html_ (http://www.visualgps.net/NMEATime/Download/Download.html) It is supposed to generate IRIG-B on the Audio output, to provide an SNTP server, and various other time support via NMEA input, and via a 1PPS signal on the DSR/CTS port pins. Has anyone checked how accurate the SNTP server time-stamping is when using the RS-232 1PPS input? Thanks, Said ___ 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. -- Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.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] NMEA Time
Sorry no idea. It will however be offset from time if your source encodes rs232 and then you decode it... Easy way for everyone with a short wave receiver and scope would be to measure the tick on 1 channel and if I recall the pulse out or you can also look for the IRIGB leading data. As I recall its fixed and you can see it as a pattern But adding a server and etc I am sure its close to 1 second. Just did not have a need to get that detailed. I run gps connected to a pic that drives a home brew irigb gen and that drives numbers of decoders. The pic does several things. It extracts the time from gps and then calculates the proper time to acount for the irigb encoder delay. Essentially I output the next second ahead of 0 time. Liked all of this pretty well and did essentially the same trick with a smpte tc generator using jam sync. Works very well. I jam every 10 minutes so that its always on time. If power fails I jam as soon as things are stable within 10 seconds. On Wed, Nov 25, 2009 at 3:03 PM, saidj...@aol.com wrote: Hi Robert, thanks for the info. I am wondering how accurate their SNTP server with 1PPS RS-232 input is. Not sure how one would test that without specialized equipment.. bye, Said In a message dated 11/25/2009 11:26:45 Pacific Standard Time, robert8...@yahoo.co.uk writes: Hi Said, Yes it does generate IRIG B (modulated AF), I was recommended it to test a reader and it worked fine. You can download a 30 day trial for free. The website lists the limitations on the IRIG output. I didn't read them too closely as they didn't affect my application. Robert G8RPI. ___ 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] NMEA Time
saidj...@aol.com said: thanks for the info. I am wondering how accurate their SNTP server with 1PPS RS-232 input is. Not sure how one would test that without specialized equipment.. What sort of accuracy do you want? You aren't going to get nanosecond accuracy out of a ntp server running over an ethernet[1]. On the other hand, sub-ms isn't hard with a good OS and/or good software. It's fairly easy to get a reasonable sanity check on a (s)ntp server. Just setup a known good ntp system and have it monitor the DUT. The reference implementation for ntp (http://www.ntp.org/) has lots of support for collecting data. The key step in making a PC keep good time is tweaking the clock frequency. This is the software equivalent of the EFC on an oscillator. ntpd calls it drift. You can use it as a thermometer. -- 1) There is a group working on that level of accuracy. It takes special hardware that can put a time-stamp on a packet as it leaves or arrives. http://en.wikipedia.org/wiki/Precision_Time_Protocol -- 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.
Re: [time-nuts] NMEA Time
You aren't going to get nanosecond accuracy out of a ntp server running over an ethernet[1]. On the other hand, sub-ms isn't hard with a good OS and/or good software. It's fairly easy to get a reasonable sanity check on a (s)ntp server. Just setup a known good ntp system and have it monitor the DUT. The reference implementation for ntp (http://www.ntp.org/) has lots of support for collecting data. The key step in making a PC keep good time is tweaking the clock frequency. This is the software equivalent of the EFC on an oscillator. ntpd calls it drift. You can use it as a thermometer. I don't think the oscillator quality in the typical PC is good enough to ever get nanoseconds, even with tons of tweaks and temperature compensation, etc. The short term variability/phase noise is too high. Microseconds, I think you could do. -- 1) There is a group working on that level of accuracy. It takes special hardware that can put a time-stamp on a packet as it leaves or arrives. http://en.wikipedia.org/wiki/Precision_Time_Protocol More than just a casual group. You can buy IEEE 1588 products from, among others, Symmetricom. ___ 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] NMEA Time
Hi, I am just curious what the NMEA Time program can achieve in terms of SNTP accuracy. Millisecond accuracy would be sufficient, and should be possible with the accurate 1PPS input I would think. bye, Said In a message dated 11/25/2009 12:58:27 Pacific Standard Time, hmur...@megapathdsl.net writes: What sort of accuracy do you want? You aren't going to get nanosecond accuracy out of a ntp server running over an ethernet[1]. On the other hand, sub-ms isn't hard with a good OS and/or good software. ___ 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] Double oven ocxo's was Tbolt reception problems
Warren, Perhaps I am being too hard on the Tbolt. If I never had a Z3801, I am sure I would like the Tbolt a lot more. The Z3801 seems to just sit there and work without having to assure either its voltage or temperature or anything else for that matter. I do believe the things I am seeing are coming from the Tbolt because I compared an LPRO to the Z3801 and saw only a very slow, uniform slip in phase. No jumping around at all. By slow, I mean that it took several hours for it to slip 1 cycle. As to the double oven OCXO, I have 2 I purchased off eBay in the last few months. One is a Morion MV89 and the other a UCT 8663. I compared both to the Z3801 over several days and was not impressed. They seemed no better than a good single oven unit. Of course, I wasn't trying them over a large temperature excursion but I expected them to be better than a single oven. I wouldn't expect either of them to improve the Tbolt much. The only thing to really impress me lately has been the LPROs. They do move but seem a lot less picky about everything than a quartz oscillator. ___ 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] Double oven ocxo's was Tbolt reception problems
I have installed those UCT8663 DOXOs in lots of Tektronix DC5010 counters. They tend to be VERY nice oscillators for frequency counters. Their long term frequency drift is excellent... approaching rubidiums in many cases. After over a year of continuous operation, my main counter still reads the GPSDO as 10.000 Mhz. Out of a couple dozen units I only had one that was not considerably better than the standard Tek OCXO. It had a bad frit seal around one pin. _ Hotmail: Trusted email with powerful SPAM protection. http://clk.atdmt.com/GBL/go/177141665/direct/01/ ___ 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] Amatuer Radio Information
From: Luis Cupido cup...@mail.ua.pt ~ Hummm... What is HF ??? ;-) :-) I've always thought HF was just nervous DC. dB _ Download new and classic emoticon packs at Emoticon World Brought to you exclusively by Windows Live http://windowslive.ninemsn.com.au/emoticon.aspx? ___ 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] NMEA Time
Hi Doesn't everybody run OCXO's for the clock in their PC? Bob On Nov 25, 2009, at 4:41 PM, Lux, Jim (337C) wrote: You aren't going to get nanosecond accuracy out of a ntp server running over an ethernet[1]. On the other hand, sub-ms isn't hard with a good OS and/or good software. It's fairly easy to get a reasonable sanity check on a (s)ntp server. Just setup a known good ntp system and have it monitor the DUT. The reference implementation for ntp (http://www.ntp.org/) has lots of support for collecting data. The key step in making a PC keep good time is tweaking the clock frequency. This is the software equivalent of the EFC on an oscillator. ntpd calls it drift. You can use it as a thermometer. I don't think the oscillator quality in the typical PC is good enough to ever get nanoseconds, even with tons of tweaks and temperature compensation, etc. The short term variability/phase noise is too high. Microseconds, I think you could do. -- 1) There is a group working on that level of accuracy. It takes special hardware that can put a time-stamp on a packet as it leaves or arrives. http://en.wikipedia.org/wiki/Precision_Time_Protocol More than just a casual group. You can buy IEEE 1588 products from, among others, Symmetricom. ___ 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] Double oven ocxo's was Tbolt reception problems
John Green wrote: As to the double oven OCXO, I have 2 I purchased off eBay in the last few months. One is a Morion MV89 and the other a UCT 8663. I compared both to the Z3801 over several days and was not impressed. They seemed no better than a good single oven unit. Of course, I wasn't trying them over a large temperature excursion but I expected them to be better than a single oven. We demonstrated thermal gains of over 1 million in the E1938A single oven oscillator. You don't need a double oven. 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.
Re: [time-nuts] Double oven ocxo's was Tbolt reception problems
Rick Karlquist wrote: John Green wrote: As to the double oven OCXO, I have 2 I purchased off eBay in the last few months. One is a Morion MV89 and the other a UCT 8663. I compared both to the Z3801 over several days and was not impressed. They seemed no better than a good single oven unit. Of course, I wasn't trying them over a large temperature excursion but I expected them to be better than a single oven. We demonstrated thermal gains of over 1 million in the E1938A single oven oscillator. You don't need a double oven. While the E1938A has very good specs, there arn't that many floating around the second hand market and to the best of my knowledge no one manufacturing them (please tell me otherwise!). I also think that the E1938A performance and design-details may not be known or at least used by that much people outside this group and the obvious HP/Agilent staff. 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] NMEA Time
paul swed wrote: Sorry no idea. It will however be offset from time if your source encodes rs232 and then you decode it... Easy way for everyone with a short wave receiver and scope would be to measure the tick on 1 channel and if I recall the pulse out or you can also look for the IRIGB leading data. As I recall its fixed and you can see it as a pattern But adding a server and etc I am sure its close to 1 second. Just did not have a need to get that detailed. I run gps connected to a pic that drives a home brew irigb gen and that drives numbers of decoders. The pic does several things. It extracts the time from gps and then calculates the proper time to acount for the irigb encoder delay. Essentially I output the next second ahead of 0 time. Liked all of this pretty well and did essentially the same trick with a smpte tc generator using jam sync. Works very well. I jam every 10 minutes so that its always on time. If power fails I jam as soon as things are stable within 10 seconds. Are the PIC and irigb encoder written up any place. I have a couple of GPS receivers and an irig display and I would like to connect them. Been meaning to build an irig encoder myself. Bill K7NOM ___ 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] PC time
On Wed, 25 Nov 2009, Bob Camp wrote: Hi Doesn't everybody run OCXO's for the clock in their PC? Bob you should make one of those text displays on the bottom of your email that reads: my PC clock is controlled by an HP10811 That distinguishes Time-Nuts members from the general public. ___ 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] Double oven ocxo's was Tbolt reception problems
John Comparing Z3801 and Tbolts, although they do the same thing, Is hard, like apples and oranges. Depending on what performance one is after, they both have strength and weaknesses. One of the Z3801 biggest advantages is it Double Osc. The size and original cost of that one item is likely more and bigger than the whole Tbolt. The more amazing thing is how the Tbolt can do as well as it does with it's simple, smaller and cheaper OXCO. And even here it is not all clear cut. The BEST Tbolts of a large run will outperform the worse (and maybe the average) Z3801. But I have no doubt that the average Tbolt will come in second to the average Z3801 in many performance categories, mostly due to Z3801's DOCXO. Now if I was tinkering with a 3801, Or any precision instrment for that matter, the first thing I do is come up with several modifications to make it even better, This really has little to do with the Tbolt, it is just because that is what I like to do. Given a Z3801, it would not take long to have a list of how to make it even better. My personal opinion is when comparing unmodified GPSDO, the average Z3801 is the better unit because of its double Oven expensive Osc and better Default settings BUT, That can all be changed or Fixed. My real turn on for the Tbolt is that I feel that its GPS engine is much better than the Z3801's GPS engine which is the real limit on how good the performance can be improved. I'll bet that the ultimate modified Tbolt is going to be a lot better than a standard OR modified Z3801. ws [time-nuts] Double oven ocxo's was Tbolt reception problems John Green wpxs472 at gmail.com Warren, Perhaps I am being too hard on the Tbolt. If I never had a Z3801, I am sure I would like the Tbolt a lot more. The Z3801 seems to just sit there and work without having to assure either its voltage or temperature or anything else for that matter. I do believe the things I am seeing are coming from the Tbolt because I compared an LPRO to the Z3801 and saw only a very slow, uniform slip in phase. No jumping around at all. By slow, I mean that it took several hours for it to slip 1 cycle. As to the double oven OCXO, I have 2 I purchased off eBay in the last few months. One is a Morion MV89 and the other a UCT 8663. I compared both to the Z3801 over several days and was not impressed. They seemed no better than a good single oven unit. Of course, I wasn't trying them over a large temperature excursion but I expected them to be better than a single oven. I wouldn't expect either of them to improve the Tbolt much. The only thing to really impress me lately has been the LPROs. They do move but seem a lot less picky about everything than a quartz oscillator. ___ 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] Double oven ocxo's was Tbolt reception problems
Rich You don't need a double oven with the E1938A Maybe the E1938A does not need it, BUT it SURE does helps the average OXCO to keep it at a VERY constant temp when looking at parts in e-12 freq changes. How about the 10811-60158? I think? that (or some version of it) is what is used in the Z3801A. My testing shows that the ones I have sure need their outer ovens working to get the best performance, even over just small room temp changes. ws *** - Original Message - From: Rick Karlquist rich...@karlquist.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, November 25, 2009 5:18 PM Subject: Re: [time-nuts] Double oven ocxo's was Tbolt reception problems John Green wrote: As to the double oven OCXO, I have 2 I purchased off eBay in the last few months. One is a Morion MV89 and the other a UCT 8663. I compared both to the Z3801 over several days and was not impressed. They seemed no better than a good single oven unit. Of course, I wasn't trying them over a large temperature excursion but I expected them to be better than a single oven. We demonstrated thermal gains of over 1 million in the E1938A single oven oscillator. You don't need a double oven. 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.
Re: [time-nuts] NMEA Time
james.p@jpl.nasa.gov said: I don't think the oscillator quality in the typical PC is good enough to ever get nanoseconds, even with tons of tweaks and temperature compensation, etc. The short term variability/phase noise is too high. Microseconds, I think you could do. Yes, mostly. PCs have two nasty disadvantages in terms of time keeping. One is that the CPU clock is typically using spread spectrum to make the EMI shielding (a lot) easier. The other is that the temperature at the crystal depends (a lot) on what the CPU is doing. -- 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.
Re: [time-nuts] NMEA Time
Hi, Reaching low millisecond accuracy (or even resolution) might be hard in a M$WIN environment, where the system timer tick is 10ms. There is also a Multimedia Timer with 1ms ticks. http://msdn.microsoft.com/en-us/magazine/cc163996.aspx someone having a recent reference to time(r) resolution and NTP accuracy in Windows? I think you should grab your favorite free unix flavor and the reference NTP implementation to reach ms accuracy. -- Björn Hi, I am just curious what the NMEA Time program can achieve in terms of SNTP accuracy. Millisecond accuracy would be sufficient, and should be possible with the accurate 1PPS input I would think. bye, Said In a message dated 11/25/2009 12:58:27 Pacific Standard Time, hmur...@megapathdsl.net writes: What sort of accuracy do you want? You aren't going to get nanosecond accuracy out of a ntp server running over an ethernet[1]. On the other hand, sub-ms isn't hard with a good OS and/or good software. ___ 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] Amatuer Radio Information
Just to hit one point... On Wed, Nov 25, 2009 at 09:37:51AM -0600 I heard the voice of J. Mike Needham, and lo! it spake thus: As far as equipment is concerned, I am on a tight budget and so it will likely be eBay and Craigslist, but I am not sure what I need these days. [...] I need an antenna that would be the least obtrusive and not mounted in a permanent fashion to the building. An antenna can never be too good. But don't underestimate what you can do with a really bad one. Several years ago, I finally got around to getting on HF, and I lived in an apartment at the time. I used a Small Wonder Labs 30 meter transciever you build for about $100 (mod a few tools etc you should have around anyway), which put out about 900 mW. That went through the cheapest manual tuner I could buy, and into ~100 feet of wire which was taped up one wall, across the ceiling, around a corner, up the stairs, looped around a room, down a vertical wall, across another wall... the first contact that landed was something like 850 miles away. Same antenna, with a standard commercial transceiver and ~20 watts (wouldn't want to go higher, what with my head and computer and all being about 2 feet from the antenna) crossed both oceans. Pretty bad setup, really. But it worked. So don't get too hung up on finding the perfect8-} N3TZJ -- Matthew Fuller (MF4839) | fulle...@over-yonder.net Systems/Network Administrator | http://www.over-yonder.net/~fullermd/ On the Internet, nobody can hear you scream. ___ 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.
