Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS
On Sat, 18 Feb 2012 18:59:21 -0800 Eric Lemmon wb6...@verizon.net wrote: I hooked up a linear triple-output bench supply to run the Thunderbolt, and now the 8040C locked up perfectly on the 1 PPS signal. Since I don't want to tie up one of my bench power supplies to run the Thunderbolt, I plan to try adding some filters to the outputs of the T-30B switcher. I'm thinking that some low-ESR tantalum capacitors might do the trick. Rather than re-invent the wheel, I wonder if others found this problem, and what their solution was. The usual way to filter such low frequency noise components is to use T or Pi filters. But it also depends on how the noise looks like. Is it spikes? Is it a sine? Or triangles? If there are spikes, add some ceramic capacitors as well, depending on the nature of the spikes something between 10n and 10u. Having 10n, 1u, 10u is mostly a good compromise for high frequency clamping. If the noise is sine or triangle like, try with the mentioned T and Pi filters, maybe multiples of those. I also wonder if this T-30B power supply requires a minimum load on any of its outputs, for it to operate properly. Hmmm. Yes, all switching power supplies (and DC/DC converters) have a minimum load requirement. What it is, depends on the controller used. Modern controllers change from PWM mode to PFM (aka pulse skip) to keep the efficiency high. Some (notably chips from Linear) have something they call burst mode, ie they do a few switching cycles to drive the voltage up, then sleep for an extended time. If you can figure out what chip your power supply is using, you can probably force it to PWM mode, but then you have to ensure that you enhance the cooling of the switching transistors as they will run much hotter. Alternatively, you can use a power supply that gives you an intermediate voltage (somewhere between 10 and 15V) and use high speed DC/DC converters that work with switching frequencis in the MHz range instead of 100-300kHz of an AC/DC supply to generate the voltages needed by the thunderbolt. This should reduce the noise quite a bit. If you are really time-nutty, you can let the DC/DC converters produce a voltage about 1V above what you need and use low noise LDOs (ie not the 78xx or LM317 Co) to produce the voltages for the thunderbolt. This should give you a 60-80dB damping of the noice produced by the DC/DC converters. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long 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] Fwd: FE-5680A Contact FEI
On Sun, 19 Feb 2012 01:07:04 -0500 Peter Gottlieb n...@verizon.net wrote: Do you believe there may be a problem for those who are reverse-engineering, and posting on the open net, items which may be covered under these regulations? Not unless you live in the US. Then you are bound by the laws of your country. But then again, most of the stuff we deal with is not of clasified nature, it's just that the companies who work in the arms, military and defense business are paranoid. Checking each bit of information whether it would be export restricted or not would mean a lot more work than just to declare everything as classified. That in the long term they hurt themselves by this is an other issue and because it cannot be numberd in $$$ for this quaters budget, not of the concern of those who decide such policy. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long 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] ebay warning
On Tue, 21 Feb 2012 15:06:18 -0800 Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Feb 21, 2012 at 2:33 PM, Tom Knox act...@hotmail.com wrote: Sadly I heard recently that the US is 27th in Math and 25th in Science. I challenge the old DXers too name 25 countries smarter then we are. I cannot. Does it really matter? If you are building iPhones what you need are only a half dozen really smart leaders, a few hundred good engineers and thousands of semi-skilled assembly line workers and another thousand who can work cash registers and swipe credit cards. Everyone does not need to have an advanced degree from Harvard.It has been like that for ages: One cave man figured out how to make fire then 100 others said fire good. I make fire too. Yes it does matter: http://wulffmorgenthaler.com/2012/02/18/ Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long 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] ebay warning
On Mon, 27 Feb 2012 10:10:26 +0100 Attila Kinali att...@kinali.ch wrote: On Tue, 21 Feb 2012 15:06:18 -0800 Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Feb 21, 2012 at 2:33 PM, Tom Knox act...@hotmail.com wrote: Sadly I heard recently that the US is 27th in Math and 25th in Science. I challenge the old DXers too name 25 countries smarter then we are. I cannot. Does it really matter? If you are building iPhones what you need are only a half dozen really smart leaders, a few hundred good engineers and thousands of semi-skilled assembly line workers and another thousand who can work cash registers and swipe credit cards. Everyone does not need to have an advanced degree from Harvard. It has been like that for ages: One cave man figured out how to make fire then 100 others said fire good. I make fire too. Yes it does matter: http://wulffmorgenthaler.com/2012/02/18/ Attila Kinali I realize someone already mention Idiocracy.. [bump]Yes it does matter[bump] Steve ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
On 2/27/2012 12:48 AM, Attila Kinali wrote: If you are really time-nutty, you can let the DC/DC converters produce a voltage about 1V above what you need and use low noise LDOs (ie not the 78xx or LM317 Co) to produce the voltages for the thunderbolt. This should give you a 60-80dB damping of the noice produced by the DC/DC converters. Attila Kinali Having designed LDO chips, people expect them to perform miracles well beyond reality. If you have a PNP pass and you are sitting near dropout, you get control loops that are an ugly combination of a path to keep the PNP from getting saturated plus one to control the voltage. With P-fet pass devices, the control is better (no sat killer needed with a fet), but still you are trying to regulate with what amount to be a variable resistor. You really don't get that much filtering at switcher frequencies with LDOs, plus some regulators can't handle too low of an ESR. If you care about noise, screw efficiency and go with a shunt regulator. There are hack circuits on the net to take 431s plus external components to roll a decent shunt. Note the shunt regulator makes the DC/DC happy by presenting a uniform load. If you do a shunt right, the bypass capacitor will do all the work. This is somewhat true with a P-fet pass regulator, where Cds is forming a cap divider with your bypass. I never really warmed up to PNP pass devices, but they are best for high voltage applications. ___ 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] Schematic capture, anyone?
On Fri, 24 Feb 2012 10:41:37 -0800 Chris Albertson albertson.ch...@gmail.com wrote: A good feature to look for is autorouting. and design rule checking. Of course every engineer thinks he is smarter than this kind of software. Mostly he is but it is good to use software that simply will not allow some kinds of errors. Design rules generally are things like following the schematic and the geometry of traces and limits of the PCB fab like line widths. I've used rat's nest routing too. This allows you to place the parts on the PCB and then does the interconnects with as the crow flies traces that cross and can't possibly work but they are drawn in red. you click them one at a time and rout them. As you place components you can see the rats net and you move them around to minimize the crossings. I advice against the use of autorouting. It's not that the engineer is so much smarter than the router, but it's that the engineer has much more knowledge than the router to know what those wires carry and which ones should be short, which wide, which do not really matter if they have a small trip around the PCB... Of course, you can annotate the schematics with all that info in order to get the autorouter to the point it can beat you. But it'll take much longer than doing it yourself. The usual way i do routing, is to use rats nest place the parts and see whether i can route the important signals nicely. Then route those first. If the PCB is complex (either too many highly interconnected componets, or not enough space) i often do a first run to asses how the connections will look like when routed and after that a second run with adjusted placement. Attila inali -- Why does it take years to find the answers to the questions one should have asked long 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] Power Supply Noise Affects Thunderbolt 1 PPS
Having designed LDO chips, people expect them to perform miracles well beyond reality. If you have a PNP pass and you are sitting near dropout, you get control loops that are an ugly combination of a path to keep the PNP from getting saturated plus one to control the voltage. I never really warmed up to PNP pass devices, but they are best for high voltage applications. I was under the impression that the industry as a whole got away from PNP pass back in the 80s. Off the top, I can't think of any PNP pass regulation designs worth using. You've got my curiosity when you mentioned high voltage. Seems to me that PNP is even worse at high voltage, owing to the majority holes as carriers rather than majority electrons as in NPN. Why are PNP better for high voltage than NPN? (I've been using PNP for nearly everything for about 20 years) .. every now and then i get lazy and grab a PNP, but that's beyond the context ;) Steve ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
Having designed LDO chips, people expect them to perform miracles well beyond reality. If you have a PNP pass and you are sitting near dropout, you get control loops that are an ugly combination of a path to keep the PNP from getting saturated plus one to control the voltage. I never really warmed up to PNP pass devices, but they are best for high voltage applications. I was under the impression that the industry as a whole got away from PNP pass back in the 80s. Off the top, I can't think of any PNP pass regulation designs worth using. You've got my curiosity when you mentioned high voltage. Seems to me that PNP is even worse at high voltage, owing to the majority holes as carriers rather than majority electrons as in NPN. Why are PNP better for high voltage than NPN? (I've been using PNP for nearly everything for about 20 years) .. every now and then i get lazy and grab a PNP, but that's beyond the context ;) No matter how many times i read something, I miss a major typo and don't see it until right after I hit send! Should read: (I've been using NPN for nearly everything for about 20 years) Steve ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Morion MV89A Repair
Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
On Mon, 27 Feb 2012 01:29:11 -0800 gary li...@lazygranch.com wrote: On 2/27/2012 12:48 AM, Attila Kinali wrote: If you are really time-nutty, you can let the DC/DC converters produce a voltage about 1V above what you need and use low noise LDOs (ie not the 78xx or LM317 Co) to produce the voltages for the thunderbolt. This should give you a 60-80dB damping of the noice produced by the DC/DC converters. Having designed LDO chips, people expect them to perform miracles well beyond reality. If you have a PNP pass and you are sitting near dropout, you get control loops that are an ugly combination of a path to keep the PNP from getting saturated plus one to control the voltage. With P-fet pass devices, the control is better (no sat killer needed with a fet), but still you are trying to regulate with what amount to be a variable resistor. Hmm.. i had the impression if you stayed beyond two times the drop out voltage that the regulation loop could take most of everything? And afaik all modern LDOs are FET types? Aren't they? You really don't get that much filtering at switcher frequencies with LDOs, plus some regulators can't handle too low of an ESR. Modern LDOs all handle zero ESR. And they have to. But yes, switcher frequency filtering is something you should do with lots of Cs and maybe some Ls. That's another reason why i said to use DC/DC converters with MHz switching frequency. It makes it much easier to filter them out. If you care about noise, screw efficiency and go with a shunt regulator. There are hack circuits on the net to take 431s plus external components to roll a decent shunt. Note the shunt regulator makes the DC/DC happy by presenting a uniform load. Yes, that would be also a possibility. But it only makes sense if you have a more or less constant power consumption. Otherwise you'll just waste the peak current (plus some headroom) permanently. Eg, with a OCXO you'd have to design the regulator for the heating current. And when the OCXO goes into steady state, you waste ~80% of the energy to heat the enclosure. If you do a shunt right, the bypass capacitor will do all the work. This is somewhat true with a P-fet pass regulator, where Cds is forming a cap divider with your bypass. I don't exactly see how the Cds helps with regulation as a capacitive divider. Could you elaborate this a little bit. I never really warmed up to PNP pass devices, but they are best for high voltage applications. While the notion of high voltage is constantly moving up :-) Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long 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] Morion MV89A Repair
Roberto It is called tens of years of experience Bert Kehren In a message dated 2/27/2012 5:16:28 A.M. Eastern Standard Time, rbarri...@msn.com writes: Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
Those were bicmos designs where the LDO was to provide voltage for running controller chips. I've only done PMOS for stand alone LDO. -Original Message- From: Steve iteratio...@gmail.com Sender: time-nuts-boun...@febo.com Date: Sun, 26 Feb 2012 23:54:20 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS Having designed LDO chips, people expect them to perform miracles well beyond reality. If you have a PNP pass and you are sitting near dropout, you get control loops that are an ugly combination of a path to keep the PNP from getting saturated plus one to control the voltage. I never really warmed up to PNP pass devices, but they are best for high voltage applications. I was under the impression that the industry as a whole got away from PNP pass back in the 80s. Off the top, I can't think of any PNP pass regulation designs worth using. You've got my curiosity when you mentioned high voltage. Seems to me that PNP is even worse at high voltage, owing to the majority holes as carriers rather than majority electrons as in NPN. Why are PNP better for high voltage than NPN? (I've been using PNP for nearly everything for about 20 years) .. every now and then i get lazy and grab a PNP, but that's beyond the context ;) Steve ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
The p-fet LDO can never do better than a cap divider formed by Cds and the load. Just draw the circuit and this is obvious. There is always a feedthrough path via Cds. I'm not so sure LDOs can handle perfect caps. ;-) -Original Message- From: Attila Kinali att...@kinali.ch Sender: time-nuts-boun...@febo.com Date: Mon, 27 Feb 2012 11:23:22 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS On Mon, 27 Feb 2012 01:29:11 -0800 gary li...@lazygranch.com wrote: On 2/27/2012 12:48 AM, Attila Kinali wrote: If you are really time-nutty, you can let the DC/DC converters produce a voltage about 1V above what you need and use low noise LDOs (ie not the 78xx or LM317 Co) to produce the voltages for the thunderbolt. This should give you a 60-80dB damping of the noice produced by the DC/DC converters. Having designed LDO chips, people expect them to perform miracles well beyond reality. If you have a PNP pass and you are sitting near dropout, you get control loops that are an ugly combination of a path to keep the PNP from getting saturated plus one to control the voltage. With P-fet pass devices, the control is better (no sat killer needed with a fet), but still you are trying to regulate with what amount to be a variable resistor. Hmm.. i had the impression if you stayed beyond two times the drop out voltage that the regulation loop could take most of everything? And afaik all modern LDOs are FET types? Aren't they? You really don't get that much filtering at switcher frequencies with LDOs, plus some regulators can't handle too low of an ESR. Modern LDOs all handle zero ESR. And they have to. But yes, switcher frequency filtering is something you should do with lots of Cs and maybe some Ls. That's another reason why i said to use DC/DC converters with MHz switching frequency. It makes it much easier to filter them out. If you care about noise, screw efficiency and go with a shunt regulator. There are hack circuits on the net to take 431s plus external components to roll a decent shunt. Note the shunt regulator makes the DC/DC happy by presenting a uniform load. Yes, that would be also a possibility. But it only makes sense if you have a more or less constant power consumption. Otherwise you'll just waste the peak current (plus some headroom) permanently. Eg, with a OCXO you'd have to design the regulator for the heating current. And when the OCXO goes into steady state, you waste ~80% of the energy to heat the enclosure. If you do a shunt right, the bypass capacitor will do all the work. This is somewhat true with a P-fet pass regulator, where Cds is forming a cap divider with your bypass. I don't exactly see how the Cds helps with regulation as a capacitive divider. Could you elaborate this a little bit. I never really warmed up to PNP pass devices, but they are best for high voltage applications. While the notion of high voltage is constantly moving up :-) Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long 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. ___ 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] Odetics 365 date/1024 week problem fix
I was working for Zyfer (Odetics) when they did this mod. Yes, the only difference between the 365 and 565 models is the GPS engine, firmware and different front panel. And yes, that backlight control has caught quite a few people out in the past!! Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur Dent Sent: 27 February 2012 00:22 To: time-nuts@febo.com Subject: [time-nuts] Odetics 365 date/1024 week problem fix I have owned an Odetics 365 GPStar Plus Time And Frequency System for some time and it works fine except for the annoying date problem that apparently has something to do with the fairly common 1024 weeks limit where older GPS receivers display 2012 as 1992 and the day of the year is not correct. I couldn't just change receivers because there appeared to be some routines in the firmware that checked the receiver model and interpreted the data for specific models that Odetics could have used in the late 1990s. This 365 used a Magellan 5000 OEM receiver. I recently got a good deal on a FEI-Zyfer (Odetics) 565 that looks like the 365 and it was sold as-is because there was just a backlight but no display and the keypad was dead. What it turned out to be was the display contrast was turned way down and the 'beep' was turned off. The unit worked properly but as it was received it did look dead. I bought the 'dead' 565 hoping that maybe I could compare the two units and find a way to fix the 365 to display the date properly. Getting a fully operational 565 was a bonus. What was very interesting to me was that the 365 (~1998) and the 565 (~2005) had basically identical motherboards. The only difference I could see was one 27c010 eprom and the receiver and its adaptor board. I put the 565 eprom and receiver into the 365 and it became a 565 displaying the correct time and date and working exactly like the 565. The receiver in the 565 was a Motorola M12+ on a Synergy Systems adaptor board that made the M12+ look like an older and larger Motorola UT+ board to the 565. I tried a UT+ in place of the M12+ and it worked fine and the unit identified it properly as a UT+ V2.2. I then duplicated the eprom and made an adaptor board for the UT+ board because the Synergy Systems adaptor board for the M12+ would UT+ be too difficult to copy. The adaptor board I made just has the UT+, a 7805 3-terminal 5V regulator, a back-up super cap, and a 7404 buffer (1 inverter driving 3 in more in parallel) for the 1 PPS out. The RX and TX from the UT+ receiver are also connected so the 365 with the new eprom and receiver sees all the proper signals and works as a 565 should. I've attached a photo of the M12+ factory made board and the UT+ board I made so you can see what they look like. I thought that others who have run into this same problem might find this information helpful. http://farm8.staticflickr.com/7052/6787095870_1199bfd85d_b.jpg -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Morion MV89A Repair
Hi Bert, I've googled for that and didn't find a related paper :-) Regards, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: lunes, 27 de febrero de 2012 11:44 To: time-nuts@febo.com Subject: Re: [time-nuts] Morion MV89A Repair Roberto It is called tens of years of experience Bert Kehren In a message dated 2/27/2012 5:16:28 A.M. Eastern Standard Time, rbarri...@msn.com writes: Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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.
Re: [time-nuts] Morion MV89A Repair
Hi ...or my lack of experience. I think I first saw problems like these in 1975. Somehow they keep showing up :) Bob On Feb 27, 2012, at 5:44 AM, ewkeh...@aol.com wrote: Roberto It is called tens of years of experience Bert Kehren In a message dated 2/27/2012 5:16:28 A.M. Eastern Standard Time, rbarri...@msn.com writes: Hi Bob, I wonder what the other oscillators that others are receiving look like in the SA. Replacing all the capacitors would take a serious effort, not sure if it would be justified. Can I ask how can you know all that by looking at the spectrum plot? Thank you, Roberto EB4EQA -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: sábado, 25 de febrero de 2012 23:55 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Morion MV89A Repair Hi The spectrum you show in the middle is the correct one. It shows the 10 MHz output and the sub-harmonics related to the 5 MHz crystal oscillator. The other two are a bit broken. One appears to have a stage oscillating. The other is more interesting. It has a stage oscillating that is injection locked to the 5 MHz crystal oscillator. I suspect more than one capacitor went bad in these OCXO's. Somebody may have sold Morion a bad reel of bypass caps. Bob On Feb 25, 2012, at 4:01 PM, Roberto Barrios rbarri...@msn.com wrote: Hi all, I spent this evening repairing a MV89A that had a weak output, output cap was bad: http://www.rbarrios.com/projects/MV89A I also found while comparing with other two MV89A's that they show different output spectra, as can be seen. Test conditions were identical but one appears much cleaner than the others. What are the reasons for this? Regards, Roberto EB4EQA ___ 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.
Re: [time-nuts] 5061's on ebay - FIXED IT
Joe Good to hear that you recovered the 5061. A couple of comments. Ground screws do indeed oxidize and it can be a very good fix for older gear to simply loosen and re-tighten those screws or to replace pop riveted terminal lugs with real screws and lock washers. Nicads My experience with modern nicads are they are real crud.I spent $45 for a new set from a major supplier and they lasted a year before starting down the failed path. I believe that any nicads on the shelf are getting pretty old these days. Other amazing thing is I have tested those 30 year old nicads and amazingly they really do hold up very well. So someplace along the line the manufacturers figured out how to make them a re-occurring revenue stream. Granted today there are alternates to those evil nicads. So perhaps they have a respectable life. Regards Paul. WB8TSL On Sun, Feb 26, 2012 at 8:24 PM, J. L. Trantham jlt...@att.net wrote: Not being able to suppress my interests for too long, I explored my newly acquired 5061A this weekend. The problem was an oscillation in the A7 assembly, as determined by looking at the output at A7J6. I am not sure what I did to fix it but I removed all connections to the A7 and A8 assemblies, reconnected them, and no joy. I then removed the A7 assembly, checked the components that have frequently failed in the past on my other 5061A's, found no problems, loosened all the mounting screws for the PCB then re-tightened them, cleaned all the connections, reinstalled it, switched the 'HI' and 'LO' switch back and forth half a zillion times, left it in 'HI', adjusted the 2nd Harmonic to '40' on the meter, and, magically, everything worked. I suspect the problem will be back. I suspect a 'marginal' connection or a marginal component in the A7 assembly. I have some 'parts units' available for the next time the unit fails. Nonetheless, it has 'locked' for the past hour with a Beam I of about 13 nAmp, if my calculation is correct (-131.50 mV from the CS tube as connected to the cable from the tube to A7J1 and as measured with my Fluke 8050A with a 10 MOhm input resistance), and the output is 'locked' on my scope with it's trigger coming from my TBolt. I have ordered new batteries for the Option 02 battery pack although it even worked with only one 'dead' cell. I replaced the 'dead' cell with one that 'kinda works' from another old battery pack, and now even the backup battery pack is working, 'kinda'. Happy to answer any questions. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. L. Trantham Sent: Wednesday, February 22, 2012 9:25 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] 5061's on ebay I'll do it. I work full time and this is my hobby. So, it may be a while before I get into it though. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, February 22, 2012 9:22 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5061's on ebay Interested ___ 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] 5061's on ebay - FIXED IT
On Mon, 27 Feb 2012 08:59:02 -0500 paul swed paulsw...@gmail.com wrote: Granted today there are alternates to those evil nicads. So perhaps they have a respectable life. Not really. NiCd and NiMH are optimized for price these days, not to last long. Li-Ion and Li-Poly are even worse (optimized for power and price, not taking into account their inherently shorter life). If you want to have long lasting akkus buy those that are rated for such use. But they cost a premium. The only alternative are Pb batteries. Especially the Pb-Gel ones. Those are made to last a couple of years if not a decade or two before getting a too high internal resistance. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long 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.
[time-nuts] UK: MSF 60 KHz outages notice: March 8, March 26-April 6
Folks, I have received the following notices: __ Notice of Interruption to MSF 60 kHz Time and Frequency Signal The MSF 60 kHz time and frequency signal broadcast from Anthorn Radio Station will be shut down over the periods: 8 March 2012 from 10:00 UTC until 14:00 UTC 08:00 UTC on Monday 26 March until 20:00 UTC on Friday 6 April __ This will affect mainly UK users. 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.
Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS
Digging through the literature online, I see the high voltage LDOs are still PNP, at least for the manufacturers that show representative circuits. I was pretty such of this when you did your post, mostly because I couldn't see how you would drive the NPN and maintain a low dropout. [You would need circuitry to drive the base that would have to function a VBE above dropout.] If low droput wasn't required, then by all means, I'd design with a NPN pass device to avoid the saturation killer circuit. Some random TI parts: http://www.ti.com/lit/ds/symlink/lm9076.pdf About 30 to 40db rejection at switcher frequencies. http://www.ti.com/lit/ds/symlink/lm2931-n.pdf About 55 to 70dB rejection at switcher frequencies. Note the rejection graphs are a bit misleading since they are measured with sine inputs, while the switcher noise has plenty of harmonics. When I build a project for myself, I always use the P-fet based LDOs. Usually TI designs, though I never worked for them, so I have no inside knowledge of their design. They test fine. I just know it is substantially easier to design a LDO with a P-fet in terms of stability, simply because there is one feedback path, and MOS modeling is better than bipolar. Some of the worst LDOs I've come across are from Micrel. I can't imagine how that company stays in business. [Look at their financials and the market agrees with me.] TI, LTC, Maxim, generally good stuff, though you can usually find a stinker device if you look hard enough. Something like a LDO is usually a solo project so it depends a lot on the designer. Surprisingly, the wiki is pretty decent for LDOs, paying homage to Bob Dobkin. http://en.wikipedia.org/wiki/Low-dropout_regulator On 2/27/2012 2:46 AM, li...@lazygranch.com wrote: Those were bicmos designs where the LDO was to provide voltage for running controller chips. I've only done PMOS for stand alone LDO. -Original Message- From: Steveiteratio...@gmail.com Sender: time-nuts-boun...@febo.com Date: Sun, 26 Feb 2012 23:54:20 To:time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS Having designed LDO chips, people expect them to perform miracles well beyond reality. If you have a PNP pass and you are sitting near dropout, you get control loops that are an ugly combination of a path to keep the PNP from getting saturated plus one to control the voltage. I never really warmed up to PNP pass devices, but they are best for high voltage applications. I was under the impression that the industry as a whole got away from PNP pass back in the 80s. Off the top, I can't think of any PNP pass regulation designs worth using. You've got my curiosity when you mentioned high voltage. Seems to me that PNP is even worse at high voltage, owing to the majority holes as carriers rather than majority electrons as in NPN. Why are PNP better for high voltage than NPN? (I've been using PNP for nearly everything for about 20 years) .. every now and then i get lazy and grab a PNP, but that's beyond the context ;) Steve ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
Attila, It turns out that the MeanWell T-30B switching power supply does, indeed, require a minimum load on each output- but especially so on the +5 volt output, which powers the Thunderbolt's 10 MHz and 1 PPS output circuitry. The specs for this power supply are: +5V, 0.5-3.0A; +12V, 0.1-1.0A; and -12V, 0.1-0.5A. The actual steady-state current draws of my Thunderbolt are: +5V, 0.23A; +12V, 0.15A; and -12V, 0.003A. In order to increase the respective loads above the minimum specified levels, I added a 16 ohm 5 watt resistor on the +5 volt output, and an 82 ohm 5 watt resistor on the -12 volt output. Voila! The Thunderbolt settled down and the 8040C locked up to the 1 PPS. I really don't like to use resistors for this purpose, since they do produce some heat and waste energy- a bit less than 2 watts apiece in this instance- but it did prove that too little load on a switching power supply can be a bad thing. Thanks for sharing your thoughts on this matter. I enjoy reading your many postings, and I have learned a lot from the subjects discussed on this list. 73, Eric Lemmon WB6FLY -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila Kinali Sent: Monday, February 27, 2012 12:48 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Power Supply Noise Affects Thunderbolt 1 PPS On Sat, 18 Feb 2012 18:59:21 -0800 Eric Lemmon wb6...@verizon.net wrote: I hooked up a linear triple-output bench supply to run the Thunderbolt, and now the 8040C locked up perfectly on the 1 PPS signal. Since I don't want to tie up one of my bench power supplies to run the Thunderbolt, I plan to try adding some filters to the outputs of the T-30B switcher. I'm thinking that some low-ESR tantalum capacitors might do the trick. Rather than re-invent the wheel, I wonder if others found this problem, and what their solution was. The usual way to filter such low frequency noise components is to use T or Pi filters. But it also depends on how the noise looks like. Is it spikes? Is it a sine? Or triangles? If there are spikes, add some ceramic capacitors as well, depending on the nature of the spikes something between 10n and 10u. Having 10n, 1u, 10u is mostly a good compromise for high frequency clamping. If the noise is sine or triangle like, try with the mentioned T and Pi filters, maybe multiples of those. I also wonder if this T-30B power supply requires a minimum load on any of its outputs, for it to operate properly. Hmmm. Yes, all switching power supplies (and DC/DC converters) have a minimum load requirement. What it is, depends on the controller used. Modern controllers change from PWM mode to PFM (aka pulse skip) to keep the efficiency high. Some (notably chips from Linear) have something they call burst mode, ie they do a few switching cycles to drive the voltage up, then sleep for an extended time. If you can figure out what chip your power supply is using, you can probably force it to PWM mode, but then you have to ensure that you enhance the cooling of the switching transistors as they will run much hotter. Alternatively, you can use a power supply that gives you an intermediate voltage (somewhere between 10 and 15V) and use high speed DC/DC converters that work with switching frequencis in the MHz range instead of 100-300kHz of an AC/DC supply to generate the voltages needed by the thunderbolt. This should reduce the noise quite a bit. If you are really time-nutty, you can let the DC/DC converters produce a voltage about 1V above what you need and use low noise LDOs (ie not the 78xx or LM317 Co) to produce the voltages for the thunderbolt. This should give you a 60-80dB damping of the noice produced by the DC/DC converters. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long 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. ___ 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] VK4GHZ Thunderbolt Monitor and Commander
Just wanted to mention a terrific Thunderbolt Monitor design by VK4GHZ Adam Maurer (http://www.vklogger.com/forum). It monitors the Thunderbolt output on 4 screens (4x20 display) so no computer hookup is necessary to follow the GPS. A companion Commander makes use of a PICAXE to cause the Thunderbolt to initiate various functions such as a survey or change from 3D to over determined, among others. Adam sells the Monitor unit assembled and tested, while the Commander is easily home brewed. He's done a great job. Jim Robbins N1JR ___ 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] VK4GHZ Thunderbolt Monitor and Commander
One has to go through their sign-up process just to take a look. On 2/27/2012 10:20 PM, James Robbins wrote: Just wanted to mention a terrific Thunderbolt Monitor design by VK4GHZ Adam Maurer (http://www.vklogger.com/forum). It monitors the Thunderbolt output on 4 screens (4x20 display) so no computer hookup is necessary to follow the GPS. A companion Commander makes use of a PICAXE to cause the Thunderbolt to initiate various functions such as a survey or change from 3D to over determined, among others. Adam sells the Monitor unit assembled and tested, while the Commander is easily home brewed. He's done a great job. Jim Robbins N1JR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2113/4836 - Release Date: 02/27/12 ___ 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] VK4GHZ Thunderbolt Monitor and Commander
That doesn't seem to be the case on this side of the pond. I could read anything posted, just cannot post without signing up. 73, Dick, W1KSZ -Original Message- From: Peter Gottlieb n...@verizon.net Sent: Feb 27, 2012 8:26 PM To: time-nuts@febo.com Subject: Re: [time-nuts] VK4GHZ Thunderbolt Monitor and Commander One has to go through their sign-up process just to take a look. On 2/27/2012 10:20 PM, James Robbins wrote: Just wanted to mention a terrific Thunderbolt Monitor design by VK4GHZ Adam Maurer (http://www.vklogger.com/forum). It monitors the Thunderbolt output on 4 screens (4x20 display) so no computer hookup is necessary to follow the GPS. A companion Commander makes use of a PICAXE to cause the Thunderbolt to initiate various functions such as a survey or change from 3D to over determined, among others. Adam sells the Monitor unit assembled and tested, while the Commander is easily home brewed. He's done a great job. Jim Robbins N1JR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2113/4836 - Release Date: 02/27/12 ___ 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] VK4GHZ Thunderbolt Monitor and Commander
I'm (slowly) working on one based on Arduino. No plan to use anything like four screens. I think the way to go is one but with a rotary knob so you can scroll and click the knob to make menu selections. But then for even less cost you can make it web based. You save the cost and size of the display and control it with an iPhone or the like. On Mon, Feb 27, 2012 at 7:20 PM, James Robbins jsrobb...@earthlink.net wrote: Just wanted to mention a terrific Thunderbolt Monitor design by VK4GHZ Adam Maurer (http://www.vklogger.com/forum). It monitors the Thunderbolt output on 4 screens (4x20 display) so no computer hookup is necessary to follow the GPS. A companion Commander makes use of a PICAXE to cause the Thunderbolt to initiate various functions such as a survey or change from 3D to over determined, among others. Adam sells the Monitor unit assembled and tested, while the Commander is easily home brewed. He's done a great job. Jim Robbins N1JR ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] VK4GHZ Thunderbolt Monitor and Commander
I have known about this project for a while, I was excited at first but was put off by the price tag, the fact that it is closed source and that it's not available as a kit. There is another project on the horizon by James M1DST that is based on the Netduino platform which will be open source. http://m1dst.co.uk/ I have spoke to James via Email and the project is further ahead than what is published on his site. Direct links for the VK4GHZ Thunderbolt Display. http://www.vklogger.com/forum/viewtopic.php?f=71t=10282 http://www.vklogger.com/forum/viewtopic.php?f=71t=10277 Sam. - Original Message - From: Peter Gottlieb [mailto:n...@verizon.net] To: time-nuts@febo.com Sent: Tue, 28 Feb 2012 14:26:09 +1100 Subject: Re: [time-nuts] VK4GHZ Thunderbolt Monitor and Commander One has to go through their sign-up process just to take a look. On 2/27/2012 10:20 PM, James Robbins wrote: Just wanted to mention a terrific Thunderbolt Monitor design by VK4GHZ Adam Maurer (http://www.vklogger.com/forum). It monitors the Thunderbolt output on 4 screens (4x20 display) so no computer hookup is necessary to follow the GPS. A companion Commander makes use of a PICAXE to cause the Thunderbolt to initiate various functions such as a survey or change from 3D to over determined, among others. Adam sells the Monitor unit assembled and tested, while the Commander is easily home brewed. He's done a great job. Jim Robbins N1JR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2113/4836 - Release Date: 02/27/12 ___ 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] VK4GHZ Thunderbolt Monitor and Commander
On Mon, Feb 27, 2012 at 8:04 PM, Sam li...@digitalelectric.com.au wrote: I have known about this project for a while, I was excited at first but was put off by the price tag, the fact that it is closed source and that it's not available as a kit. There is another project on the horizon by James M1DST that is based on the Netduino platform which will be open source. Why does everyone think alike? This describes what I want to do also. Netduino is the Arduino with an Ethernet interface on it. It makes a good platform for this because there is no need to make a PCB or distribute a kit. The Arduino already has all the required connectors. Chris Albertson Redondo Beach, California ___ 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] VK4GHZ Thunderbolt Monitor and Commander
Netduino is the Arduino with an Ethernet interface on it. Not quite, The Netduino is an open-source platform using the .NET Micro Framework. http://www.netduino.com The Netduino Plus shield has on-board Ethernet. http://www.netduino.com/netduinoplus/ Sam - Original Message - From: Chris Albertson [mailto:albertson.ch...@gmail.com] To: Discussion of precise time and frequency measurement [mailto:time-nuts@febo.com] Sent: Tue, 28 Feb 2012 15:22:49 +1100 Subject: Re: [time-nuts] VK4GHZ Thunderbolt Monitor and Commander On Mon, Feb 27, 2012 at 8:04 PM, Sam li...@digitalelectric.com.au wrote: I have known about this project for a while, I was excited at first but was put off by the price tag, the fact that it is closed source and that it's not available as a kit. There is another project on the horizon by James M1DST that is based on the Netduino platform which will be open source. Why does everyone think alike? This describes what I want to do also. Netduino is the Arduino with an Ethernet interface on it. It makes a good platform for this because there is no need to make a PCB or distribute a kit. The Arduino already has all the required connectors. Chris Albertson Redondo Beach, California ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
The PNP bipolar and P-channel MOSFET architectures do provide the best low-dropout performance, but as I understand, do not provide the best HF line rejection. Looking at the overall circuit - a high gain, band-limited amplifier driving a P pass device puts it in a common-base (or -gate) mode, with respect to the amplifier's output port. It provides excellent DC performance, but high frequency noise (beyond the control loop bandwidth) at the emitter (or source) has a large voltage gain available. This is of course for positive supplies. An N device operates as a follower, and needs more overhead voltage to activate the gain as a common-collector (or -drain) amplifier, but is able to reject the input supply noise much more effectively, given the same band-limited control loop amplifier. So, for best HF noise performance where the input noise may be large, it's best to use a follower or shunt regulator topology, despite the lower efficiency - unless efficiency is more important. 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] Power Supply Noise Affects Thunderbolt 1 PPS
Ed wrote: So, for best HF noise performance where the input noise may be large, it's best to use a follower or shunt regulator topology, despite the lower efficiency - unless efficiency is more important. To put it more bluntly, the last time I looked (it has been a while, so there may be something new I haven't seen) LDOs were all substantially inferior to standard regulators in terms of noise feedthrough and HF load regulation. The rule of thumb has always been to avoid LDOs unless low dropout was the paramount concern. Has something changed with current LDO designs to make them competitive with standard regulators in terms of noise feedthrough and HF load regulation? 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] 2 out of 3 bad 5680As?
Hello, I have two units that don't produce any output and the lock pin floats around +2.3 volts continuously. The +15v load starts at about 1.8A and drops down to about 0.7A on both units, but I never get a +5V or 0V on the lock or a 10MHz out signal. (I'm not using an LED on the lock pin, just a high-impedance DVM.) I'm relatively confident in my connection setup, since I do have one unit that works as advertised. In fact, one of the bad units was a replacement from nichegeek, received about three weeks after the original first order of two units (from Amazon.com instead of China). Sorry if this is covered somewhere, but I couldn't find my symptoms on the list... any thoughts are appreciated. Thanks, 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.
Re: [time-nuts] 2 out of 3 bad 5680As?
Hi, I gather that some of these units require a +5V supply on pin 4 of the connector and some do not. Could that be the problem here? Chris -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Dave hartzell Sent: 28 February 2012 05:18 To: Discussion of precise time and frequency measurement Subject: [time-nuts] 2 out of 3 bad 5680As? Hello, I have two units that don't produce any output and the lock pin floats around +2.3 volts continuously. The +15v load starts at about 1.8A and drops down to about 0.7A on both units, but I never get a +5V or 0V on the lock or a 10MHz out signal. (I'm not using an LED on the lock pin, just a high-impedance DVM.) I'm relatively confident in my connection setup, since I do have one unit that works as advertised. In fact, one of the bad units was a replacement from nichegeek, received about three weeks after the original first order of two units (from Amazon.com instead of China). Sorry if this is covered somewhere, but I couldn't find my symptoms on the list... any thoughts are appreciated. Thanks, 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] 2 out of 3 bad 5680As?
Hi Dave, A silly question, although you did not indicate, you are supplying a separate 5 volts to the unit are you not ? BillWB6BNQ Dave hartzell wrote: Hello, I have two units that don't produce any output and the lock pin floats around +2.3 volts continuously. The +15v load starts at about 1.8A and drops down to about 0.7A on both units, but I never get a +5V or 0V on the lock or a 10MHz out signal. (I'm not using an LED on the lock pin, just a high-impedance DVM.) I'm relatively confident in my connection setup, since I do have one unit that works as advertised. In fact, one of the bad units was a replacement from nichegeek, received about three weeks after the original first order of two units (from Amazon.com instead of China). Sorry if this is covered somewhere, but I couldn't find my symptoms on the list... any thoughts are appreciated. Thanks, 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] 2 out of 3 bad 5680As?
Bill, Yes, +5v but I was doing it incorrectly (bad hookup wire on both units). I haven't checked the second bad unit, but it will probably work now too. Sometimes I have to hit the send button before I find my errors. Thanks for the thoughts, Dave On Mon, Feb 27, 2012 at 10:31 PM, WB6BNQ wb6...@cox.net wrote: Hi Dave, A silly question, although you did not indicate, you are supplying a separate 5 volts to the unit are you not ? BillWB6BNQ Dave hartzell wrote: Hello, I have two units that don't produce any output and the lock pin floats around +2.3 volts continuously. The +15v load starts at about 1.8A and drops down to about 0.7A on both units, but I never get a +5V or 0V on the lock or a 10MHz out signal. (I'm not using an LED on the lock pin, just a high-impedance DVM.) I'm relatively confident in my connection setup, since I do have one unit that works as advertised. In fact, one of the bad units was a replacement from nichegeek, received about three weeks after the original first order of two units (from Amazon.com instead of China). Sorry if this is covered somewhere, but I couldn't find my symptoms on the list... any thoughts are appreciated. Thanks, 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. ___ 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] Power Supply Noise Affects Thunderbolt 1 PPS
Well this is the granddaddy with 3V of dropout. Not much rejection at high frequency, but the design is old. Modern LDOs are better, especially with P-fet pass device. http://www.ti.com/lit/ds/symlink/lm317-n.pdf On 2/27/2012 9:13 PM, Charles P. Steinmetz wrote: Ed wrote: So, for best HF noise performance where the input noise may be large, it's best to use a follower or shunt regulator topology, despite the lower efficiency - unless efficiency is more important. To put it more bluntly, the last time I looked (it has been a while, so there may be something new I haven't seen) LDOs were all substantially inferior to standard regulators in terms of noise feedthrough and HF load regulation. The rule of thumb has always been to avoid LDOs unless low dropout was the paramount concern. Has something changed with current LDO designs to make them competitive with standard regulators in terms of noise feedthrough and HF load regulation? 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.
Re: [time-nuts] VK4GHZ Thunderbolt Monitor and Commander
Gosh, and I just bought one from Sparkfun for another project :-) Don Chris Albertson On Mon, Feb 27, 2012 at 8:04 PM, Sam li...@digitalelectric.com.au wrote: I have known about this project for a while, I was excited at first but was put off by the price tag, the fact that it is closed source and that it's not available as a kit. There is another project on the horizon by James M1DST that is based on the Netduino platform which will be open source. Why does everyone think alike? This describes what I want to do also. Netduino is the Arduino with an Ethernet interface on it. It makes a good platform for this because there is no need to make a PCB or distribute a kit. The Arduino already has all the required connectors. Chris Albertson Redondo Beach, California ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell 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.
