Re: [time-nuts] Time-nut going England!
Seconded. Did both last August and it was great. The amount of restored hardware that's operational is impressive and docents are knowledgeable. If you get to the computing museum, having a chat with whoever is in the Colossus gallery is worth your time. Admission to BP is £17.75 and the Computing Museum is £7.50. Both are well worth the admission price plus the train ride. Cheers, John -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Clint Jay Sent: Thursday, April 27, 2017 6:16 AM To: Discussion of precise time and frequency measurement ; Dave B Subject: Re: [time-nuts] Time-nut going England! Yes, Bletchley is a good day out but be aware the national museum of computing is a separate entity and has its own entry fee. On 27 Apr 2017 12:00 pm, "Dave B via time-nuts" wrote: > On 26/04/17 17:00, time-nuts-requ...@febo.com wrote: > > > Message: 12 > > Date: Wed, 26 Apr 2017 15:05:52 +0200 > > From: Attila Kinali > > To: time-nuts@febo.com > > Subject: [time-nuts] Time-nut going England! > > Message-ID: <20170426150552.93c33e4cbe356663386bb...@kinali.ch> > > Content-Type: text/plain; charset=US-ASCII > > > > Hi > > > > I'll be in the UK for three weeks and will have a "free" week > > between 13th and 20th of May. I will most probably be around the > > London area and maybe spend a day or two in Southampton. > > > > If someone wants to meet for a beer or cup of hot chocolate, or > > knows of time-nutty things to do, please let me know. > > > > I would also appreciate if someone knows an affordable place to stay > > at in London, so that it doesn't strain the purse of this poor > > student too much. > > > > Attila Kinali > > -- > -- Not exactly "TN" material, but you'd find this an interesting day > out. > > https://www.bletchleypark.org.uk/ > > Get an off peak return rail ticket from Euston to Bletchley, it's a > short walk from the rail station. > > The National museum of computing (and other special interests) are > there too. > > Else the various museums in London will more than keep you occupied! > > Regards. > > Dave B, not that far from BP, but no idea what I'll be doing the time > you plan to be in the UK. "Domestic Management" has not told me the > plans for that far ahead yet! :) > > ___ > 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] End Of The World
> As expected, on the leap second the display on the 8183 showed 6:59:60 (the > 8183-A showed 23:59:60), but the TV400 displayed 7:00:00 at that moment. > The TV400 remained one second ahead until it displayed 7:00:03 for a two- > second period, then from 7:00:04 forward it was properly synced. On the 2012 event my HP 55300A did the same thing on the IRIG output. The :03 second was repeated and then normal operation resumed. I did attempt to view the event on a 3.5" Tomtom GPS, without much joy. There's a setup screen that shows all SVs in view as well as the current UTC. When it came time to roll from 23:59:59 to 23:59:60 the time line just went blank for 1 second, then rolled to 00:00:00. Their code must be checking for 'invalid' time. Bummer ... -John ___ 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] "Better" gps antennas than a Symmetricom 58532A
>Should I make it a habbit of TDRing my GPS antennas, receivers and >splitters? > >Cheers, >Magnus I think that question ties into some of the other responses to the original post. The value of doing the TDR measurement would probably depend on your cable lengths and how likely you think it is that a connector mismatch would cause cable reflections that might smear the GPS signals. Since you're fortunate enough to have a TDR, it might be interesting to do it just to see how much mismatch there really is. If the resolution of the measurement is good enough you should be able to see all of the connectors. If nothing else, it might tell you if you have a bad cable end or a loose connection. Maybe the Italian guys should have run an optical TDR on their timing setup before doing the neutrino measurements :) -John ___ 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 Monitor
I can't help you with the outboard monitor, but I can help with the haywire / mouse situation. Windows thinks that the serial port has a mouse connected because of the 1 / second transmissions from the T-Bolt. At boot time Win looks for serial mice and it gets fooled by seeing something active on that COM port. There was an answer about this issue from Nov. 1, 2010. == > NOTE: If you boot Windows with your ThunderBolt connected to the Com > port, Windows will think it is a serial mouse and grab the port. It > can lead to some interesting Windows behavior as the T-Bolt outputs > data. > > > Mike - AA8K Easy fix. Add the following to your "Boot.ini" file. Obviously, the "x" stands for the COM port you are using. NoSerialMice:COMx Joe Gray W5JG == This didn't always work for me. Another way to get it to stop using the mouse is to boot, let it find the "mouse", and then disable it in the Device Manager. After opening Device Manager you'll find a mouse that doesn't belong there connected to whatever COM port your serial adapter was assigned. If you move the adapter to a different USB port you'll need to do the process again. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Major L. McGee III Sent: Wednesday, January 23, 2013 10:32 AM To: time-nuts@febo.com Subject: [time-nuts] Thunderbolt Monitor I have been following this on the list for a while now and was curious if anyone is actively working on a open source monitor. I see the one made by Adam VK4GHZ is no longer being sold. This got me back on track for wanting to make one of my own. I have been using either tbmon or lady heather but always have issues with a usb to serial converter when I start the computer. It will go haywire and cause it to freeze and make the mouse malfunction. Once I disconnect the converter (I have tried other makes as well) it works fine. Usually I can reconnect the converter and things will work again. What I would like to do is make a 2 or 4 line lcd readout to display various info. I really liked VK4GHZ's page type selector knob. I can see that being very useful. On a youtube video by n6vmo said the thunderbolt used a ASCII Hex and "needs to be converted by using 64 bit floating point math". So are any of you currently working on this or have decided to quit and have any information to share? ___ 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] "Better" gps antennas than a Symmetricom 58532A
Fat fingers. Replace "test" with "rest". < snip > And it's not clear that there's actually "loss" due to mismatch. Most antennas/preamps/receivers don't have exactly 50 ohm impedances. 75/50 is only 1.5:1, and there's an awful lot of antennas and receivers out there that only claim 2:1 VSWR. The usual spec for the antenna is 1.5:1, so for all you know the Antenna and Receiver is already 75 ohms, and RG6 will give you a better match than 50 ohm LMR400. < snip > An excellent point. A similar issue is the connectors. If you read the data sheets for many common connectors and adapters you'll find that a lot of them are only rated for a 1.2:1 VSWR. I ran into this issue a few years ago when trying to measure reflection coefficient in a system using TNC connectors. It turned out that the connectors set the VSWR limit, not the test of the measuring system. -John ___ 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] "Better" gps antennas than a Symmetricom 58532A
< snip > And it's not clear that there's actually "loss" due to mismatch. Most antennas/preamps/receivers don't have exactly 50 ohm impedances. 75/50 is only 1.5:1, and there's an awful lot of antennas and receivers out there that only claim 2:1 VSWR. The usual spec for the antenna is 1.5:1, so for all you know the Antenna and Receiver is already 75 ohms, and RG6 will give you a better match than 50 ohm LMR400. < snip > An excellent point. A similar issue is the connectors. If you read the data sheets for many common connectors and adapters you'll find that a lot of them are only rated for a 1.2:1 VSWR. I ran into this issue a few years ago when trying to measure reflection coefficient in a system using TNC connectors. It turned out that the connectors set the VSWR limit, not the test of the measuring system. -John ___ 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] HP-53132A Faded and flickering display
<- snip -> Two possibilities: Cathode poisoning or bad tantalum caps. I'm not sure if "cathode poisoning" is really the correct term for this effect, but it's similar. There have been a number of tutorials out there about rejuvenating VF displays. <- snip -> It appears that the military parts system has the EL displays listed for replacement purposes. http://www.wbparts.com/rfq/5980-01-396-4645.html http://www.iso-group.com/Public/PartDetail/CP3033A/12619547/12619547.aspx Should the display prove to be beyond recovery it might be possible to buy a new one. Now, the cost may be another matter ... These are made by Noritake-Itron. The generic part number is CP3033A, but it does not show up in their product line on their web site. It might be worth contacting them to see if there's any possibility of still getting them. http://www.noritake-elec.com/contact_us.htm Searching for Itron CP3033A turns up some parts brokers that claim to have access to 251 of them. -John ___ 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] HP-53132A Faded and flickering display
Edgardo, Two possibilities: Cathode poisoning or bad tantalum caps. I'm not sure if "cathode poisoning" is really the correct term for this effect, but it's similar. There have been a number of tutorials out there about rejuvenating VF displays. The one I have direct experience with is bad caps. We bought an HP 6612C power supply with a bad display for an automated test setup. It's basically the same VF display used in a lot of the instruments from that family. We didn't really need the display because it was for an automated setup, but I wanted to fix it anyway. When I removed the display board I found that it had 3 or 4 large tantalum caps on one edge. One of the caps was toasted a crispy brown color instead of the usual yellow. After replacing that cap the display came right back to life and has been working fine for a couple of years, now. BTW: those display and button boards are a bit of a trick to remove. They're slide in from the side under some "L" shaped plastic features in the case front. There are instructions in the service manual for dealing with them. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Edgardo Molina Sent: Friday, November 02, 2012 11:24 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] HP-53132A Faded and flickering display Dear Group, Good morning! I just got my first HP-53132A frequency counter and Prologix GPIB-USB converter. Now I can do some measurements and I am excited about it. Everything looks promising. Condition of the instrument on the outside is like new, controls responsive and no fading in lettering at the buttons. Connectors are not worn or damaged, original connectors. The unit has been tested and works OK, probably not with adequate calibration but that is not an issue now, I can always calibrate it later. What worries me is the display. Even though being an Agilent built unit, it has probably more hours on it than a seldom used HP built unit. The flourescent display is fading, not all the digits show consistent illumination levels. The left-most digits show some flickering at some of their segments. It is readable in the end, but I am terribly disappointed about it. Does anybody know if there is a cure for this? Or should I start saving for a better unit. I am not afraid of the screwdriver or the soldering iron if someones suggests a display overhaul. Thank you! Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. ___ 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] GPS receiver testing
Thank you to all of the respondents. There is a lot of great information in the replies. Based on more interaction with our customer it's looking like we may need to send the unit(s) out to a facility that specializes in this area. Best regards, John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Lux Sent: Wednesday, October 31, 2012 8:39 PM To: time-nuts@febo.com Subject: Re: [time-nuts] GPS receiver testing > Hello Said, > > I'm familiar with your postings on the Time Nuts list, so I thought I'd > ask your advice. I searched the Time Nuts archive, but didn't come up with > what I was looking for (reference to a good GPS tutotial). > > We have a GPS project in-house that requires us to characterize receiver > module performance. We have a Litepoint IQ-Nav box with several stored > scenarios, but no other signal generators with GPS personalities in them. We > need to measure position accuracy and time accuracy. We may also need to > get some characterization of the 1 PPS output. > There's folks at JPL who do this kind of thing all the time.. I'll ask who you should contact.. It kind of matters on what you're testing for, but I'm sure there's someone who can point you in the right direction. Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS receiver testing
Thank you very much for the thorough reply. Best Regards, John From: saidj...@aol.com [mailto:saidj...@aol.com] Sent: Wednesday, October 31, 2012 3:17 PM To: John Lofgren; time-nuts@febo.com Subject: Re: GPS receiver testing John, thanks for your email, I am replying to Time Nuts as well as there is a lot of knowledgeable folks here that can help. In terms of a GPSDO tutorial, take a look at the HP papers linked on the JLT website under the "Links Of Interest" and "Related Whitepaper" sections: http://www.jackson-labs.com/index.php/support In terms of how to measure the 1PPS accuracy and how to set up the equipment, see the paper labeled "Critical evaluation of the Motorola M12+ receiver" on that page. Explains how to set up the Agilent counter I mention below. There is a lot of threads in the time nuts archives discussing the pro's and con's of different equipment, but let me give you a quick guide to what worked well for me: For 1PPS measurements and frequency stability down to the ~2E-010 level per second you can get a low-costAgilent 53132A counter. In order to check GPS position accuracy, you may want to get a timing GPS receiver that can do position-averaging using Auto Survey features. Such as the Trimble Thunderbolts, the JLT Mini-JLT GPSDO, or the HP58503A units. The JLT unit is the only unit using WAAS augmentation, so it probably has a much quicker and more accurate position indication than the other units mentioned. Let it average the position of your antenna for a day or two, and you will likely have an accuracy at the centimeter level (horizontal) and at the foot level vertical. Beware of different GPS datums, e.g. MSL versus GPS height indications etc. You can use those GPSDO as a reference for your counter as well. The above equipment can be had with a couple of days shipping time from Ebay, at around $1500 to $2000 totaland will serve you well for a very long time, and the resolution of the counter (150ps) is likely much higher than the GPS sawtooth error from the GPS you mentioned. If you need much more accuracy and resolution, get a Wavecrest DTS time interval analyzer from Ebay for around $800, those have picosecond averaged noise floors, femtosecond hardware resolution, and 10ps single shot resolution. In order to measure the 1PPS stability and accuracy, you would input the GPSDO reference 1PPS and your GPS 1PPS into the counter, and set it to T1 to T2 time interval measurement can capture that data. You may or may not use an external 10MHz reference for the counter doing this measurement, it shouldn'tmake a difference to your results.Then download Ulrich Bangerts excellent freeware "Plotter" program to do the time-stability analysis (search Google for "Bangert Plotter" and you will find his website). Please note that you may or may not want to use the GPS receiver sawtooth correction data on your dataset, either manually (using Excel to subtract the offset error), viaa delay line, or other mechanism in your system. It will make a significant difference in your stability. To measure frequency, feed the GPSDO reference into the ref-in port of the counter, your DUTto the A input, then use the "offset" feature to remove the carrier frequency, then capture the frequency offset of your source to a file, and again use Ulrich's plotter to give you the time-stability info etc. Be warned, once you start on above path, you are likely never to stop searching for the holy grailof references, and measurement equipment.. Hope that helps, Said In a message dated 10/31/2012 12:36:55 Pacific Daylight Time, jlofg...@lsr.com writes: Hello Said, I'm familiar with your postings on the Time Nuts list, so I thought I'd ask your advice. I searched the Time Nuts archive, but didn't come up with what I was looking for (reference to a good GPS tutotial). We have a GPS project in-house that requires us to characterize receiver module performance. We have a Litepoint IQ-Nav box with several stored scenarios, but no other signal generators with GPS personalities in them. We need to measure position accuracy and time accuracy. We may also need to get some characterization of the 1 PPS output. I know that you do these types of measurements frequently. Could you point me to a good reference on correctly performing these tests and, maybe, describe the equipment you are using? We're checking through Agilent and R&S application papers, but you seem to have a lot of the required knowledge readily available. Any help you could provide would be appreciated. Best regards, John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Jammer
The 0.5 W and + 10 dBm numbers in the specs don't work out. +10 dBm is 10 mW. I suspect that the 1/2 watt is really the DC input power. And, I'd agree about the range. +10 dBm into a dipole at 10 meters gets you about -44 dBm at the receiver antenna in a free-space model. That's really loud compared to the nominal -130 to -140 dBm you'd hear from the satellites. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Tuesday, October 02, 2012 4:02 PM To: time-nuts@febo.com Subject: Re: [time-nuts] GPS Jammer On 10/02/2012 10:43 PM, J. Forster wrote: > Take a look at the specs of this unit: > > http://www.mobilephonejammer.com.au/covert-gps-jammer-portable-p-119.html > > The Power Output is 0.5 Watts and it claims a jamming range of 1-10 Meters. > > Anybody think there is something wrong? For a 500 mW jammer your jamming range should be much better. That's wrong. 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. ___ 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] Hi Power LED Light power supply...
I would hence believe that a 50 Hz flicker must be pretty close to the edge of what can be perceived, so I'm having trouble believing that a flicker at more than twice that rate would be perceptible at all by anyone. Oh, but it is. A couple of years ago I bought one of the Chinese 30 LED spot light bulbs for about $8 on ebay. I thought I'd give it a try for a workbench light. When I plugged it in at work (60 Hz power, here) the two guys standing behind me yelled "gaahhh" at the same time I did. The flicker was horrendous. The earlier comment about peripheral vision also applies, though. It's worse in the periphery than in direct view. The "power supply" is nothing more than a bridge rectifier, two current limiting resistors, and a filter capacitor. The capacitor obviously wasn't big enough, though, because it flcikered plenty. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Dennis Ferguson Sent: Tuesday, September 18, 2012 1:52 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Hi Power LED Light power supply... On 18 Sep, 2012, at 12:42 , Chris Albertson wrote: > On Tue, Sep 18, 2012 at 5:21 AM, Bob Camp wrote: >> Hi >> >> I suspect those same 120Hz sensitive people would not be able to watch TV or >> a movie :) > > In the old CRT type TV sets, the phosphor has some persistence. > Movies are modulated with a square waves, the frame blinks off and > goes dark then blinks on. But the LED's brightness is fast enough to > track the sine wave and would be bright only for an instant with quick > pulses of light. Just to add to this... Ontario, Canada originally ran its power grid at 25 Hz. When they switched the grid to 60 Hz in the 1930's some of the industrial power users, particularly in northern Ontario where private (usually hydroelectric) power generators were common, never got around to changing their plants over. Mine and paper mills using 25 Hz power were common as recently as the 1980's, and might still be there for all I know. Standard incandescent light bulbs don't have a lot of persistence when run on 25 Hz power (I assume there might have been a time when you could buy incandescent bulbs designed for 25 Hz, but not in my lifetime). They don't go entirely off, but they get significantly dimmer in the visible spectrum in the dips as the output red-shifts towards the infrared; they follow the sine pretty well. In my teens, when visiting a place using 25 Hz power for lighting, I could initially see an incredibly annoying flicker when I first got there but after a minute or two this would fade and I'd no longer notice it. Some other people would also see the flicker but others, including my parents, couldn't see it at all so there seemed to be variation (maybe age-related, maybe not) among individual abilities to see this. Dennis Ferguson ___ 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] RE; New Wrist watch
Unfortunately I don't have that article, anymore, but I remember the basics from it. The author used one of the Radio Shack piezo sounder elements as the pickup. It was one of the 3 wire styles designed for an external oscillator circuit. I think it might have been around 1 cm diameter. The part I can't remember is the amplifier. It could have been a PLL or may have just been a high gain video amplifier, like the MC1350. Anyway, if somebody wants to look for the article it was somewhere in the 1985 to 1995 timeframe. There are also commercial tools from Horotec and others built for this purpose. Just google "watch tester" and you'll find a host of products. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert LaJeunesse Sent: Wednesday, September 12, 2012 7:49 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RE; New Wrist watch If I recall correctly it was in RF Design magazine many years ago that a short article included a schematic for using an ultrasonic sensor and selective amplifier (narrowband PLL?) to pick up the 32KHz vibration and convert it to a measurable signal. I'd expect a normal microphone to pick up way too much extraneous noise such that the 32KHz could not be successfully recovered. Bob L. From: Azelio Boriani azelio.bori...@screen.it Interesting: trying to "hear" a low frequency crystal using a microphone... it should be hard: the crystal has to make the case vibrate and this is energy consuming (unless it resonates). I don't expect to pick up nothing, except the step motor driving the hands. On Wed, Sep 12, 2012 at 9:45 AM, Hal Murray wrote: > Has anybody "listened" to such a watch? (with a microphone) > > Can you hear both the 32KHz basic timekeeping as well as the "tick" when > the > second hand takes a step? ___ 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] time-nuts Digest, Vol 95, Issue 74
Yes, Adam, you're correct. In RF board layouts it's usually good practice to not allow ground fill under most components on the copper layer where the component is mounted. Some specific exceptions exist for filters, amplifiers, etc. where the copper is needed for lowering the ground impedance or increasing thermal flow. In the specific case with the crystal filters the ground was also opened up in the layers below the inductors. It was either a 4 or 6 layer board and we made a rectangular cutout in the fill on the RF ground layer and power layer below each inductor. The bottom layer ground fill was left intact. Part of the issue with the board we were updating was that the RF ground layer was very close to the top component layer. The whole board thickness was something less than the usual 0.062" and the height from the top to RF ground was something like 0.008". In this case there's pretty strong coupling from the inductors into the ground. On a 2 sided 0.062" board it's probably less of an issue. The second part of the issue was the inductor type. These were wirewound inductors with values in the mH range. Their external field (and stray coupling) will be different than a nH range ceramic multilayer part. As always, YMMV. Each case will be a little different depending on frequency, component construction, and board stack. -John -Original Message- From: Adam [mailto:ab...@gmx.com] Sent: Friday, June 22, 2012 10:04 AM To: time-nuts@febo.com Cc: John Lofgren Subject: Re: time-nuts Digest, Vol 95, Issue 74 I'm learning a bunch here about filters and pcb techniques. Got one question that I'm hoping somebody could help me out with: > Date: Thu, 21 Jun 2012 13:39:01 + > From: John Lofgren > > One thing we have found that helps, though, is voiding the ground underneath > the inductor. I did some searching on Google, and found the term "voiding the ground" with regard to pcb's, but I couldn't find anywhere that actually said what that meant. Is it getting rid of the copper under the component? Does that apply to both sides of a double sided pcb? Anybody willing to help a newbie? Inquiring minds . . . . thanks, --adam, wh6m ___ 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] 10 MHz low pass filter
The inductors used in this board look like multilayer ceramic chip types. They actually have a fairly low stray field around them and they're "wound" around an axis that's perpendicular to the PCB. Most of the solenoidal coupling will be in the axis normal to the board. While rotating inductors relative to each other is a good general practice it doesn't help much in this instance. One thing we have found that helps, though, is voiding the ground underneath the inductor. In filters where you're trying to get more than about 40 dB of rejection it's possible to have coupling through induced ground currents that will just end up bypassing the filter by coupling from one stage to the next. We had a case in the past where we were fixing a customer design that used a 2 stage crystal filter. The filter nulls were off by something like 20 dB from the data sheets and the measured data from the filter vendor. Standing the in/out matching inductors up vertically and wiring them back down to the board made the response look like it should. Voiding the ground under the inductors on the next board spin fixed the problem. Self inductance and self resonance of the capacitors is always something to watch out for. The general rule of thumb we use for generic NPO multilayer chip capacitors is an inductance on the order of 1.0 to 1.3 nH for 0402 or 0603 size parts. The better RF specific parts from MuRata, ATC, and Johanson will have lower inductance and higher SRF. Typically a good bypass capacitor for 900 MHz is 18 to 22 pF and for 2.4 GHz it's 6.8 or 8.2 pF. At 10 Mhz and the first few harmonics values on the order of 1 to 20 nF would be below SRF. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Thomas S. Knutsen Sent: Wednesday, June 20, 2012 6:57 PM To: li...@lazygranch.com Cc: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 10 MHz low pass filter I don't have any problems with rotating the inductors, after all, that is one of the best way to avoid coupling between them, but the main problem as I see with that board is that there are 2 caps that would become an series resonance with the inductance in the via to reach the ground plane. Of course, at 10MHz this is just theoretical, since the problem most probably would appear above 500MHz, and the 50'th harmonic of an OXCO should be low. My experience says that the inductance in the capacitor it self should be low, specialy if NP0 or such capacitors caps are used. An 10MHz sallen key lowpass may be interesting to build,and with the GHz bandwith op-amps avaible today, it should work great. Thomas. 2012/6/21 > ** > In the days when I had access to a network analyzer with a chip component > fixture (all calibrated of course), I tested components on hand just to see > how ideal they were. Chip resistors are quite good. The inductance is > basically the electrical length of the device. Caps can be decent. My > recollection is Johanson had some really good (low parasitic) caps. > Inductors basically suck. > > You will note in most RF board design with lumped elements, they rotate > adjacent inductors to reduce mutual inductance. > > 10MHz is probably too low in frequency for practical stripline. You could > probably do active filters these days, but the power budget would not be > trivial. > > -- > *From: * "Thomas S. Knutsen" > *Date: *Thu, 21 Jun 2012 01:17:02 +0200 > *To: *; Discussion of precise time and frequency > measurement > *Subject: *Re: [time-nuts] 10 MHz low pass filter > > Based on that PCB, I want to see an sweep to at least 1GHz. > The reason is that experience have shown that the inductance (perhaps > 10nH) in series with C2 and C6 would damage the stop-band rejection at UHF. > > Used with an OXCO this would not matter, but the desire to make the > ultimate filter is still there. > > Thomas. > > 2012/6/21 > >> If the output is buffered, there really shouldn't be a problem. >> >> Incidentally, I can crank out high order LCR filters all day just by >> transforming prototypes out of Zverev. But it has been my experience at >> even 10MHz the parasitics of the elements will throw off the design. >> >> >> -Original Message- >> From: Bob Camp >> Sender: time-nuts-boun...@febo.com >> Date: Wed, 20 Jun 2012 17:49:37 >> To: Discussion of precise time and frequency measurement< >> time-nuts@febo.com> >> Reply-To: Discussion of precise time and frequency measurement >> >> Subject: Re: [time-nuts] 10 MHz low pass filter >> >> Hi >> >> That's a pretty high order filter. The output of most OCXO's already has >> a filter on it. Combining two filters (especially high order ones) without >> isolation between them is not a good idea. The resulting transfer function >> will not be what you expect it to be >> >> Bob >> >> On Jun 20, 2012, at 4:54 PM, Joseph Gray wrote: >> >> > I came across t
Re: [time-nuts] wwvb weak on east coast especially when the pre-amps under water.
This place has them, plus some other stuff that may be of interest to RF types building outdoor devices: http://www.sealingdevices.com/products/gore-vents Unfortunately it looks like you need to ask for a quote, so they may not be open to small orders. Also, McMaster Carr has an assortment of non-Gore breathers using porous bronze or stainless: http://www.mcmaster.com/#breather-vents/=hjnav7 Click on the "Breather Vents" in the upper left. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of George Dubovsky Sent: Tuesday, May 15, 2012 7:03 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] wwvb weak on east coast especially when the pre-amps under water. All, W.L.Gore and Associates makes a whole line of these things, but I'm not sure where you go to buy just one. http://www.gore.com/en_xx/products/venting/protective/index.html?xcmp=ijdgpvmktgurl 73, geo - n4ua On Tue, May 15, 2012 at 2:59 AM, Attila Kinali wrote: > On Mon, 14 May 2012 18:01:01 -0400 > Joseph M Gwinn wrote: > > > Modern outdoor enclosures use a filter of some kind, but the underlying > > principle is the same. > > I don't know what other types are around, but we use vents with > a gore-tex foil over them. Keeps water out but lets the case breath. > This prevents any pressure build up, which would then start to suck > watter in from the seal. > > Unfortunately, i'm currently unable to find the maker or the type of > the vent... If anyone is interested in those, i'll can ask around. > >Attila Kinali > > -- > The trouble with you, Shev, is you don't say anything until you've saved > up a whole truckload of damned heavy brick arguments and then you dump > them all out and never look at the bleeding body mangled beneath the heap >-- Tirin, The Dispossessed, U. Le Guin > > ___ > 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] Chinese Scopes
One feature of the Agilent and Rohde scopes (maybe Tek, too?) that can help in some situations is segmented memory. It allows you to capture periodic or random events with the full sample rate but to ignore all the dead time between events. For each trigger it stores one sweep with a time stamp. When you want to look at the record you can roll back through memory and look at each individual event with full resolution. This isn't a cure-all because the time stamps will have limited resolution and some amount of jitter, but it can be helpful in some applications. It also assumes that you know what you're looking for and can trigger on it :) -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Lux Sent: Tuesday, April 17, 2012 9:27 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Chinese Scopes On 4/17/12 6:56 AM, shali...@gmail.com wrote: > I agree that memory depth is an under appreciated parameter, but even 2,500 > points like what's available on the cheap Tek scopes is quite useful. > > On the other hand, I had a few LeCroy with 50k deep memories and there are > cases where that is very useful too. I can't imagine real life use cases when > I would need multiple MB. It would be nice to have but seldom used. > oddly enough, I had a case where very deep memory was useful last fall. It was an issue with logic that was switching from one clock source to another where the clocks were orders of magnitude different frequency (10Hz and 300kHz or something like that), and it was the relative timing of the edges that was important, so you needed a bunch of cycles of the low frequency clock (i.e. record length of half a second or so), but enough samples to see the timing of the 300kHz at the same time. Another deep memory use was when I used a fast 20GHz sample rate Tek scope a few years back (2007) debugging a radar target simulator (for the landing radar that's going to be used to land on Mars in August) and deep buffers were nice there, because we essentially needed to capture multiple pulses that were 4 ns to several microseconds long. The requirement was that the delta phase (and time) of successive pulses be within a certain value (the radar used what's known as "two pulse doppler") following a pre-programmed simulated descent profile. We also wanted the pulse timing after the trigger to be accurate to, as I recall, 0.5 or 1 ns. The PRF is pretty high, so you don't have time to unload the memory in between pulses. So we did something like 500 pulses, captured 16,384 samples at a time at 20GS/sec to make a dataset of 16 million samples. You learn a lot about what's hidden in the specs on inexpensive signal generators like the Agilent E4421B when you start comparing phase for 1600 pulses 1 microsecond apart. ___ 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] 5370B heatsink temperature
I believe so. I don't own a 5370B, but I remember the thread. What I was thinking of starts here: http://www.febo.com/pipermail/time-nuts/2010-September/050384.html Or the complete thread is available here: http://answerpot.com/showthread.php?1285452-Questions+about+HP+5370B -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Eric Garner Sent: Friday, March 09, 2012 12:22 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5370B heatsink temperature This is on my HP 5370B time interval counter. it's the external heatsink by the power inlet. -eric On Fri, Mar 9, 2012 at 10:16 AM, Chris Albertson wrote: > On Fri, Mar 9, 2012 at 10:08 AM, Eric Garner wrote: >>.. i noticed that the heatsink was REALLY hot. I used my IR >> thermometer to check it and it read ~160F(71C). > > What heat sink? Did you have the cover off and were measuring the > internal bar they use as a sink or was your FE5680A screwed down to a > large aluminum heat sink. Were all the dozen or so screws in > place? Was in making good contact > > > -- > > 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. -- --Eric _ Eric Garner ___ 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] 5370B heatsink temperature
Check the archives on this one. There have been several discussions in the past about high heatsink temperatures. Some users have added external fans to them to get the temperature down. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Eric Garner Sent: Friday, March 09, 2012 12:09 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 5370B heatsink temperature I just acquired my first HP 5370B off of ebay. After I had it running for 30 min to get it warm and start doing the checkout procedures in the manual i noticed that the heatsink was REALLY hot. I used my IR thermometer to check it and it read ~160F(71C). This seems excessively hot to me. What's "normal"? i didn't see it in the manual, but I might have missed it. -- --Eric _ Eric Garner ___ 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] FE5680 missing PPS soln
I did the same thing when I first tested mine. I mounted the regulator and a pair of SMA jacks right to the board it came with using the big board copper as the heat sink for the regulator. I didn't want to build a driver for the LED so I wired it directly (with resistor, of course). Dim and logic low was way up at 2.3 volts. I solved the problem using a high efficiency LED (P/N C503B-RCS-CW0Z0AA1 from Digi-Key). It's running at a bit over half a mA using a 6.2k resistor to the 5 V supply. Now the logic low level is at about 700 mV (still a bit high) and the PPS output works. The LED is bright enough to see from way across the lab. The current generation of LED chemistries is really impressive. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of bob grant Sent: Thursday, February 02, 2012 2:46 PM To: time-nuts@febo.com Subject: [time-nuts] FE5680 missing PPS soln Some info... Its tempting to attach an LED to the /LOCK signal on the DB9. However this signal is very weak and the LED does not seem very bright and PPS signal does not pulse...Hmm Internally the /LOCK pin is connected the 74AC240 buffer, but with an LED helping to keep the signal voltage high (2.3V) a logic low is never asserted. This logic low is needed to enable one half of the 74AC240 buffer (pin 1) that gates the PPS signal. Don't directly drive LEDs from the LOCK signal on the DB9 and, voila, the PPS signal reappears. Bob -- bob grant bobgr...@fastmail.fm -- http://www.fastmail.fm - Choose from over 50 domains or use your own ___ 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] Simple Super Ripple Eater
There have been discussions in the past about ways to reduce regulator output noise or clean-up oscillator or voltage reference power supplies. Here's an article from Design Ideas in Electronic Design that looks promising. It has pretty decent rejection even at 1 Hz. http://electronicdesign.com/article/power/Simple-Super-Ripple-Eater-Also-Cleans-Battery-Based-Supply.aspx Note that the figures don't display properly (at least in Firefox) with anything but the embedded links in the text. - John ___ 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] time-nuts Digest, Vol 89, Issue 51
There's a system that the motorcycle guys call the Whitworth Inch, but I think may be more correctly called Whitworth Measure. It's an old British system that was used on their motorcycles and possibly cars, too. There's a whole subculture of people trading in Whitworth tools for BSA and Norton owners. -John >I've seen two other systems, but their names are eluding me at this time. >Also, I've come across bolts that are not SI, nor SAE. I believe they are >considered a british thread but i'm not certain. > >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] the care and feeding of LPRO's
>fortunately, everything in the "lab"(basement) is on UPSs so in theory >the input voltages to the equipment should be pretty constant and I >was already planning on using a linear supply. Be careful, there. Most consumer type UPSs are not line regulators. When there is sufficiently high line voltage they are completely out of the circuit and the line voltage is passed through to the output unaffected. They're usually not designed for continuous operation of the inverter circuit. There was a more in-depth discussion of this a while back in a thread about running 50 / 60 Hz clocks from a locked frequency source. One possibility, though, would be a ferroresonant line regulator, like a Sola transformer. If you can tolerate the acoustic noise and the high power dissipation they will do a somewhat decent job of reducing line fluctuations. IIRC the output is also not necessarily a sine wave (depends on the design). -John ___ 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] Bob Pease
Thank you. A good friend of mine is a huge Bob Pease fan and also a devout non-wearer of seat belts. He's already used-up one of his nine lives on an accident where he wasn't belted-in. Hopefully this unfortunate reminder will cause him to change his mind about belt use. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris Sent: Monday, June 20, 2011 9:42 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Bob Pease One important thing to note is he wasn't wearing his seat belts. All you old codgers, and immortal young bucks, that think not wearing seat belts will allow you to fly free and live in an accident need to take your blinders off and pay attention: Flying free and living after an accident only happens in Hollywood. In the real world, YOU DIE! I have lost too many otherwise intelligent friends from this same idiotic act of insanity. Most in accidents under 25MPH. Most within a couple miles of their homes. The only one that didn't die had serious brain damage that left her with a stammer, crutches for life, and took away her brilliant musical talent. Several that did die left behind spouses, and a host of children. Several were childhood friends, that were children at the time of their deaths. Buckle up! Wear your seat belts! PLEASE! -Chuck Harris Javier Herrero wrote: > More or less ... > > http://www.amazon.com/How-Drive-into-Accidents-Not/dp/0965564819 > > Very sad that two great analog designers had passed away in the same week. ___ 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] Kode TCU 285 info wanted
Hi Paul, This one isn't a GPSDO, AFAIK. It looks like a stand-alone tape controller that accepts either SLO code or IRIG input. My main use for it was just as an IRIG clock display, but it doesn't seem to want to work like that. - John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Thursday, May 05, 2011 6:30 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Kode TCU 285 info wanted A bunch of pre 91 rcvrs used down converters at the antennas. Did you get the antenna with your unit? On Thu, May 5, 2011 at 5:50 PM, John Lofgren wrote: > I don't think so. All of the chips that have date codes I can decipher are > from late 1984, or earlier. > > I probably should have been more specific, too. It's a model 285-202/NC > with a serial number of 011710. > > > -John > > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of paul swed > Sent: Thursday, May 05, 2011 4:22 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Kode TCU 285 info wanted > > I have nothing. Though recently have gotten a pair of Odetics GPStars > working with Pete Lancashires (Think thats misspelled) help. > Can you tell if its newer then 1994? > Regards > > On Thu, May 5, 2011 at 4:54 PM, John Lofgren wrote: > > > > > Does anybody have any information available for a Kode (Odetics) model > 285 > > Time Code Unit? I've checked the usual places (google, BAMA, Didier's > site, > > etc.) and haven't come up with anything. I see that this question was > asked > > in 2008 and 2009, also. Just checking to see if anything new has come to > > light. > > > > Ideally I'd like to find a service manual but a simple operating manual > > would be of some help. > > > > > > Thanks, > > > > John > > > > > > > > ___ > > 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] Kode TCU 285 info wanted
I don't think so. All of the chips that have date codes I can decipher are from late 1984, or earlier. I probably should have been more specific, too. It's a model 285-202/NC with a serial number of 011710. -John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Thursday, May 05, 2011 4:22 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Kode TCU 285 info wanted I have nothing. Though recently have gotten a pair of Odetics GPStars working with Pete Lancashires (Think thats misspelled) help. Can you tell if its newer then 1994? Regards On Thu, May 5, 2011 at 4:54 PM, John Lofgren wrote: > > Does anybody have any information available for a Kode (Odetics) model 285 > Time Code Unit? I've checked the usual places (google, BAMA, Didier's site, > etc.) and haven't come up with anything. I see that this question was asked > in 2008 and 2009, also. Just checking to see if anything new has come to > light. > > Ideally I'd like to find a service manual but a simple operating manual > would be of some help. > > > Thanks, > > John > > > > ___ > 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] Kode TCU 285 info wanted
Does anybody have any information available for a Kode (Odetics) model 285 Time Code Unit? I've checked the usual places (google, BAMA, Didier's site, etc.) and haven't come up with anything. I see that this question was asked in 2008 and 2009, also. Just checking to see if anything new has come to light. Ideally I'd like to find a service manual but a simple operating manual would be of some help. Thanks, John ___ 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 reader?
Hi Jim, Try Serialmon: http://www.serialmon.com/ It has a NMEA packet decoder built in. - John -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Mandaville Sent: Thursday, January 07, 2010 8:42 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] NMEA reader? I'm totally new to this semi-DIY gps stuff. Can anyone recommend any NMEA packet reader software that will work on my old Windows 98 laptop (using data through the RS-232 serial)?. Searching online I find a lot of rather expensive software that does much more than I want to do. Any shareware or cheapware that just gives a window with lat, long, time and the usual other stuff? Jim ___ 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.
