Re: [time-nuts] Opamp datasheet noise specs and their relation to phase noise
Thanks Charles. That should keep me busy for a while. :) On 14 March 2015 at 01:51, Charles Steinmetz csteinm...@yandex.com wrote: Stephan wrote: Any good texts on the subject that you can recommend? I don't own any texts with comprehensive discussions of AM to PM conversion or low-PN design. The best sources will most likely be papers. Some good search terms are AM to PM conversion (or AM/PM conversion) and low phase noise design (or low PN design). Here are a few to get you started: The Art of Phase Noise Measurement (Scherer, Hewlett Packard, 1985) www.thegleam.com/ke5fx/Scherer_Art_of_PN_measurement.pdf Phase Noise and AM Noise Measurements in the Frequency Domain (Lance, et al., 1984) http://tf.nist.gov/general/tn1337/Tn190.pdf RF and Microwave Phase Noise Measurement Seminar (HP, 1985) www.thegleam.com/ke5fx/HP_PN_seminar.pdf Phase Noise Measurement Using the Phase Lock Technique (Motorola AN1639, 1999) www.datasheetarchive.com/AN1639-datasheet.html Phase Noise in RF and Microwave Amplifiers (Boudot, Rubiola, 2010) arxiv.org/pdf/1001.2047 Origin of 1/f PM and AM Noise in Bipolar Junction Transistor Amplifiers http://tf.nist.gov/timefreq/general/pdf/1134.pdf Guidelines for designing BJT Amplifiers with Low 1/f PM and AM Noise http://tf.nist.gov/timefreq/general/pdf/1139.pdf PM Noise Generated by Noisy Components http://tf.nist.gov/timefreq/ general/pdf/1244.pdf Best regards, Charles ___ 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] serial parsing program
I'd like to find a program that has a very flexible serial input and can be easily setup to parse a binary sentence. Specifically, U-Blox timing but more general purpose would be nice for future projects. Has to be able to handle 1, 2, and 4 byte fields, and checksums would be nice also. Should run on Windows for the immediate project but Linux for next projects. -- S. Cash Olsen KD5SSJ ARRL Technical Specialist ___ 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] serial parsing program
RealTerm is my go-to for this sort of thing on Windows, though it might not be quite as flexible as you'd like. Linux: just mung together a pipeline involving things like xxd, awk, grep.. Henry On Tue, Mar 24, 2015 at 3:22 PM, Cash Olsen radio.kd5...@gmail.com wrote: I'd like to find a program that has a very flexible serial input and can be easily setup to parse a binary sentence. Specifically, U-Blox timing but more general purpose would be nice for future projects. Has to be able to handle 1, 2, and 4 byte fields, and checksums would be nice also. Should run on Windows for the immediate project but Linux for next projects. -- S. Cash Olsen KD5SSJ ARRL Technical Specialist ___ 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] serial parsing program
Hello Cash, Check out Google Protocol Buffers https://developers.google.com/protocol-buffers/ And here is a discussion of it from an embedded software perspective http://www.ganssle.com/tem/tem277.html#article1 Hope that helps. Regards, Abdul -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Cash Olsen Sent: Tuesday, March 24, 2015 3:22 PM To: time-nuts@febo.com Subject: [time-nuts] serial parsing program I'd like to find a program that has a very flexible serial input and can be easily setup to parse a binary sentence. Specifically, U-Blox timing but more general purpose would be nice for future projects. Has to be able to handle 1, 2, and 4 byte fields, and checksums would be nice also. Should run on Windows for the immediate project but Linux for next projects. -- S. Cash Olsen KD5SSJ ARRL Technical Specialist ___ 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] serial parsing program
Hi Cash, Have you looked at the sourcecode for the gpsd package? packet.c would probably be your starting point. The gpsd package parses pretty much every gps receiver. I'm not sure if this is what you're looking for, or if you specifically want something high-level. Bob From: Cash Olsen radio.kd5...@gmail.com To: time-nuts@febo.com Sent: Tuesday, March 24, 2015 5:22 PM Subject: [time-nuts] serial parsing program I'd like to find a program that has a very flexible serial input and can be easily setup to parse a binary sentence. Specifically, U-Blox timing but more general purpose would be nice for future projects. Has to be able to handle 1, 2, and 4 byte fields, and checksums would be nice also. Should run on Windows for the immediate project but Linux for next projects. -- S. Cash Olsen KD5SSJ ARRL Technical Specialist ___ 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] Comparing the BeagleBone Black Raspberry Pi asNTP servers
From: Neil Schroeder The other key key key item is make sure you hand build yourself a 3.14 or .16 kernel. NS = Thanks, Neil. I'm afraid I have neither the expertise nor the patience to do that, and to an extent this was intended to be an out-of-the-box comparison. Doubtless adding a TCXO would improve performance as well, but I will leave that to someone else to try. I was really interested to see how much effect the extra Ethernet latency of the Raspberry Pi added in a real-world scenario. Thanks to Philip Gladstone, I have now discovered a way of significantly reducing that latency, so that the delay reported by NTP is reduced from ~0.51 to ~0.35 milliseconds. http://www.satsignal.eu/ntp/RaspberryPi-notes.html#EthernetLatency Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] M12+ Site Survey
Hello, I apologize if this question has been asked before. I have a frequency standard that uses the M12+ to discipline a rubidium oscillator. I set the M12+ to do a site survey and then set it to position hold mode for best accuracy. My question is: If I then move the unit, for example 30 miles and leave it in position hold (without doing another site survey) How will the accuracy of the 1 pps pulse be affected? In this instance, I don’t actually care about alignment to UTC. I’m just worried about the accuracy of the 1 pps pulse and ultimately the accuracy of my rubidium’s frequency. I’m about to do some testing, but wondered if anyone had an answer already. Best Regards Martyn ___ 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] Z3810AS PPS to a Raspberry Pi
On Mon, 23 Mar 2015 19:25:33 -0700 Chris Albertson albertson.ch...@gmail.com wrote: I'm surprised to can't get the Pi to interrupt on the raising edge of the PPS and that you had to make the pulse longer. That's because the rpi does not have GPIO's like other SoC or uC. When i wrote that it's a graphics card with attached usb controller, i wasn't joking. The processor on the rpi was originally designed as a test system to verify the graphics core on real workload. To interface it to the outside world, they decided to use USB. For unknown reasons they decided to use an arm9 core with a bit of glue logic as USB controller (the best guess i've heard sofar is, that they would have had to pay for a real USB controller, while an old arm core like that costs (almost) nothing if you buy a big/new one anyways). This is the reason why there are no I2C or SPI interfaces, and everything needs to be bitbanged (aka, you write single bits to outputs in software and poll whether anything changes on the inputs). Or that the USB controller generates an interrupt every 125us that _must_ be handled imediatly (the arm core has to set up the next USB microframe otherwise USB stops working). That is also the reason why Eben Upton got it so cheaply. Apparently, broadcom had produced quite a few of those (couple thousand, don't ask me why). And there was no risk that anyone would buy those (for above reasons, they were never intended to be sold). Also, the mask set (the most expensive part of chip production) was already there and amortized by other means, so producing more wouldn't cost much either. Attila Kinali -- _av500_ phd is easy _av500_ getting dsl is hard ___ 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] M12+ Site Survey
On Tue, 24 Mar 2015 19:52:30 - Martyn Smith mar...@ptsyst.com wrote: If I then move the unit, for example 30 miles and leave it in position hold (without doing another site survey) How will the accuracy of the 1 pps pulse be affected? In this instance, I don’t actually care about alignment to UTC. I’m just worried about the accuracy of the 1 pps pulse and ultimately the accuracy of my rubidium’s frequency. I think you mean precision and not accuracy[1] :-) If you leave the module in position hold and the module does not realize itself it has been moved, then the PPS will be very jittery. How much, I cannot tell (I have not seen any data of extreme off positions like that). I would guess several ms. But it would be still a pulse roughly every second. Poul-Henning had some experience with a bit off position with his M12 due to high solar activity (I've seen it on his webpage, but cannot find it at the moment). He used (uses?) an algorithm with which the receiver can creep up to its actual position over time[2]. If you move around often, i would simply disable position-hold and live with normal GPS precision, which is better than 100ns for most receivers and good sky view. HTH Attila Kinali [1] http://en.wikipedia.org/wiki/Accuracy_and_precision [2] http://phk.freebsd.dk/raga/sneak/ -- _av500_ phd is easy _av500_ getting dsl is hard ___ 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] M12+ Site Survey
Assuming pure position fix: A foot is a nanosecond. A mile is 5 microseconds. 30 miles is 150 microseconds. Quite sure the GPS would declare sanity check failure if it ever saw more than one or two satellites and saw the position fix was wrong. Tim N3QE On Tuesday, March 24, 2015, Martyn Smith mar...@ptsyst.com wrote: Hello, I apologize if this question has been asked before. I have a frequency standard that uses the M12+ to discipline a rubidium oscillator. I set the M12+ to do a site survey and then set it to position hold mode for best accuracy. My question is: If I then move the unit, for example 30 miles and leave it in position hold (without doing another site survey) How will the accuracy of the 1 pps pulse be affected? In this instance, I don’t actually care about alignment to UTC. I’m just worried about the accuracy of the 1 pps pulse and ultimately the accuracy of my rubidium’s frequency. I’m about to do some testing, but wondered if anyone had an answer already. Best Regards Martyn ___ time-nuts mailing list -- time-nuts@febo.com javascript:; 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.
