Re: [time-nuts] Conducting Bench Top Material
Atari used them by the truckload too, and again, probably due to price. I'm sure somebody is probably still producing them, or can. It was a very durable item; once, on a lark, we took one that had been run over by a truck and sat out in the weather for who knows how long, bent the pins enough to solder it to a 40pin header and tried it out in a CBM 8032it worked... I kind of wish I had been working back then when stuff was so robust Now we have poly Ta caps that have a real shelf life that's not MSL related. Dave - Original Message - From: "Poul-Henning Kamp" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, January 27, 2010 12:03:54 AM GMT -07:00 US/Canada Mountain Subject: Re: [time-nuts] Conducting Bench Top Material In message <1548123648.14120691264567016061.javamail.r...@sz0108a.emeryville.ca .mail.comcast.net>, d.sei...@comcast.net writes: >I guess I wasn't too clear; it was the bare devices we were trying to destroy; >the VIC20 was just used for testing. The 6502 was a very robust device manufactured in NMOS technology. The original target market was motorolas very lucrative military/space 6800 market, so the chip had to match or exceed the 6800 on all points, including accidental damage. The first version, the 6501 was in fact pin- but not instruction-compatible with 6800, but Motorola had a legal fit and MOS gave up on that idea. The fact that 6502 mainly ended up in Commodore computers was mainly a matter of its lower price. Later the crash in microprocessor prices saddled Jack Tramiel with a huge overpriced inventory which made him outright buy MOS to avoid a repeat performance of that problem. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Conducting Bench Top Material
In message <1548123648.14120691264567016061.javamail.r...@sz0108a.emeryville.ca .mail.comcast.net>, d.sei...@comcast.net writes: >I guess I wasn't too clear; it was the bare devices we were trying to destroy; >the VIC20 was just used for testing. The 6502 was a very robust device manufactured in NMOS technology. The original target market was motorolas very lucrative military/space 6800 market, so the chip had to match or exceed the 6800 on all points, including accidental damage. The first version, the 6501 was in fact pin- but not instruction-compatible with 6800, but Motorola had a legal fit and MOS gave up on that idea. The fact that 6502 mainly ended up in Commodore computers was mainly a matter of its lower price. Later the crash in microprocessor prices saddled Jack Tramiel with a huge overpriced inventory which made him outright buy MOS to avoid a repeat performance of that problem. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Z3801A Frequency Jump
Hi Brian, This is a classical crystal jump. Nothing one can do about it. Could have been internal to the crystal (stress-relief) or external (gamma particle hitting the crystal lattice etc). My 58503A does it every couple of days or so. Really messes with your ADEV performance... bye, Said In a message dated 1/26/2010 17:27:57 Pacific Standard Time, kilodelta4foxm...@gmail.com writes: The second drawing is a chart from Excel. The Z3801A 1 PPS was being compared against a HP5065A rubidium and this data is the 100 second averages record by TAC32. Note is shows a 200 nS jump too. The scale of the plot is in microseconds (I run a 10 uS offset for some long term drift experiments). I cannot remember what causes this from past discussions - it may be an oven regulator Brian - KD4FM ___ 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 58516A GPS distribution amplifier information
I recommend un-screwing that SMC since it is almost impossible to find the mate, and feeding two wires from a 5V supply into the unit through the hole, and soldering the wires to the PCB. Works well for me. bye, Said In a message dated 1/26/2010 18:36:18 Pacific Standard Time, bruce.griffi...@xtra.co.nz writes: > I'm using an HP 58516A GPS distribution amplifier to share my GPS > antenna between my receivers. > > What is the proper part number or connector "name" for the power > supply connector ? > > Thanks for your help ! > > Claude > > According to the datasheet option 05 uses an SMC connector for the power. Bruce ___ 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] Conducting Bench Top Material
I guess I wasn't too clear; it was the bare devices we were trying to destroy; the VIC20 was just used for testing. The largest discharge we got was from an acrylic rod and the cat. - Original Message - From: "Charles P. Steinmetz" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, January 26, 2010 7:04:11 AM GMT -07:00 US/Canada Mountain Subject: Re: [time-nuts] Conducting Bench Top Material Dave wrote: >Back about 1981, we had piles of 6502s, etc and decide to some >"antistatic testing". We put a 40pin ZIF socket into a VIC-20, and >then set about trying to fry the uP using carpet, a cat, car seats, >etc. The DUT was then put back into the VIC and series of tests run >to verify operation. I don't think we ever had a failure. Of course, >there may have been some hiding that we missed, but all the static >damage I've seen has been pretty severe. > >That said, I always use a wrist strap and mat if I'm working on >something I don't want to break further. Installed components are generally much less vulnerable to ESD than bare parts, because there are leakage paths (both intentional and otherwise) on a circuit board that allow the ESD to flow around the component rather than through it. With a naked part, any ESD to one of its leads has to flow through its other leads or the case of the device, thereby maximizing any damage. 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] HP 58516A GPS distribution amplifier information
Hi The one on mine does indeed properly mate with a SMC connector. Bob On Jan 26, 2010, at 9:35 PM, Bruce Griffiths wrote: > Claude Houde wrote: >> Hello ! >> >> I'm using an HP 58516A GPS distribution amplifier to share my GPS antenna >> between my receivers. >> >> What is the proper part number or connector "name" for the power supply >> connector ? >> >> Thanks for your help ! >> >> Claude >> >> > According to the datasheet option 05 uses an SMC connector for the power. > > Bruce > > > ___ > 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] HP 58516A GPS distribution amplifier information
Claude Houde wrote: Hello ! I'm using an HP 58516A GPS distribution amplifier to share my GPS antenna between my receivers. What is the proper part number or connector "name" for the power supply connector ? Thanks for your help ! Claude According to the datasheet option 05 uses an SMC connector for the power. Bruce ___ 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] HP 58516A GPS distribution amplifier information
Hello ! I'm using an HP 58516A GPS distribution amplifier to share my GPS antenna between my receivers. What is the proper part number or connector "name" for the power supply connector ? Thanks for your help ! Claude ___ 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] DMTD Question1
John Miles wrote: So why even talk about TC phase shifts at the ps / deg level? Who cares and who needs it? A picosecond is 1000 femtoseconds. When you're spending $100/ea. on parts rated for 60-70 fs jitter, a picosecond starts to look like a long time indeed. Does not sound like you are doing the Nuts any service to address things that are orders of Magnitude below usefulness. When designing something like this, it's useful to understand where, and why, your efforts fall short of the state of the art. That way you can be sure that the compromises you're making are the right ones. The idea is not to leave any obvious low-hanging fruit for optimization. You want to get the most out of the money you're spending, whether it's $200 or $20,000, right? I do think there's a lot of room between "state of the art" timing performance and conventional TIC-grade performance where corners can be cut and costs can be saved. It's helpful (and more interesting) if you can make those calls rationally, instead of just adopting circuits from papers and hoping for the best. Let's recall that the type of measurement varies. It may be that focus is on phase noise and short-tau instability. The concerns for long-tau instability does not apply to the same degree. The time-span of the measurement is an important aspect. Averaging techniques assumes that propeties is relatively stable over time, such that short-time noise can be filtered. Calibrations may go out of tune. Being able to crank out numbers of reasnoble reliability calls for stability of the measurement rig, beyond short-term performance. Understanding the hidden errors is important. Drift and environmental dependencies is among the issues to consider. You can have a perfectly good schematic, but still not be able to get the performance. Choice of components, mounting, etc. all add up. I find that I personal preferences towards various methods at various times, but I also find that I need to reevaluate things over and over as I get more influences. None of them is the best. Some of them has inheret drawbacks, so I need to learn how they work and what difficulties has been addressed. How is each defect handled? What does that handling imply? It's non-trivial stuff, so there is only one mode to handle it... learn more all the time. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DMTD Question1
> > So why even talk about TC phase shifts at the ps / deg level? Who > > cares and who needs it? A picosecond is 1000 femtoseconds. When you're spending $100/ea. on parts rated for 60-70 fs jitter, a picosecond starts to look like a long time indeed. > > Does not sound like you are doing the Nuts any service to address > > things that are orders of Magnitude below usefulness. When designing something like this, it's useful to understand where, and why, your efforts fall short of the state of the art. That way you can be sure that the compromises you're making are the right ones. The idea is not to leave any obvious low-hanging fruit for optimization. You want to get the most out of the money you're spending, whether it's $200 or $20,000, right? I do think there's a lot of room between "state of the art" timing performance and conventional TIC-grade performance where corners can be cut and costs can be saved. It's helpful (and more interesting) if you can make those calls rationally, instead of just adopting circuits from papers and hoping for the best. -- john, KE5FX ___ 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] DMTD Question1
Correction: The system noise floor should have been ~<1E-13/Tau for tau < 1000 sec if one wishes to replicate the performance of the Early (1976?) NIST DMTD design where wite phase noise dominates for tau up to 1000 sec or so. Bruce Bruce Griffiths wrote: Knowing the magnitude of various effects allows one to make rational choices based on one's actual or perceived requirements. Just ignoring effects which may or may not be significant and hoping that they wont be significant isn't particularly rational. The aim was a system noise floor of around 1E-13/SQRT(Tau) (for Tau up to a few hundred seconds at least) or better to ensure that this is well below the expected stability of sources being compared. There are also other uses for DMTD systems such as measuring phase instability of cables etc, that some may wish to pursue. NIST found a mixer phase shift TC of up to 75ps/K for uncompensated mixers with 5MHz inputs. If you carefully analyse your favourite frequency comparison system you may just discover why this particular technique was quietly dropped as not being particularly useful for Tau much greater than the PLL inverse loop bandwidth. The real problem is that there is no simple way to actually determine the actual Tau range for which such a system is useful other than comparing the results obtained with those from a more conventional system. Bruce WarrenS wrote: Bruce OK, Now what am I missing? I understand there are 'Freq nuts' and just 'plane NUTS', this sound like the later. With a little effort, not hard to hold the temp drift rate change to 1deg / hr (and a couple deg change altogether). Lets say the Tempco balance of the mixers was as bad a 1ns / deg That means temp change would add an addition freq error offset term of half of 3e-13 at tau of 3600 sec (36ns/hr = 1e-11) Even this gross amount would not effect the results of most of the things that any of these freq nuts would be testing including probable the best CS or RB Osc. AND if they are doing 1e-15 things, they probable want to be hold the temp to better than 0.01deg for many other reasons as well. So why even talk about TC phase shifts at the ps / deg level? Who cares and who needs it? Does not sound like you are doing the Nuts any service to address things that are orders of Magnitude below usefulness. ws ** - Original Message - From: "Bruce Griffiths" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, January 26, 2010 1:51 AM Subject: Re: [time-nuts] DMTD Question If one carefully the value of a resistor in series with both the mixer RF and LO ports and adds a 6dB attenuator between the series resistor and the output of the associated isolation amplifier its possible to reduce the mixer phase shift tempco by a factor of 10 or so. The resistor value is chosen to minimise the mixer port VSWR for the given IF port termination. At 5Mhz this can reduce the mixer phase shift tempco to less than 5ps/K. The mixer phase shift tempco also reduces as the input frequency increases (at least up to 100Mhz or so) by a factor equal to the ratio of the frequencies for which the phase shift tempco is being compared. Thus carefully matching the mixer inputs can reduce the required mixer temperature stability. It is believed that the matching reduces the effect of reflections in the input cables, so a similar effect may be achieved by using an isolation amplifier located close to each mixer input port. Bruce ___ 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] Conducting Bench Top Material
Ed Palmer wrote: Everything old is new again. The 25+ year old HP Bench Brief that I referred to a few messages back warns about that. "Nothing usefull could be found in old documents, they just didn't have the same technology as we have, and hence not the problems." Well, not that much different. Scale is the main thing. People have been studying all kinds of things, so good clues may still lay around if you dare look for them. Thanks for remembering this stuff. 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] ko4bb monitor
Although the Icruze module fluke.l sells is in a nice package for mounting on the dash of a car, I chose to build it into the same case as I did the Thunderbolt, power supply, and distribution amplifier. The power and RS-232 signal for the display is tapped off the p.c. board of the thunderbolt so the RS-232 connector on the back is still free to be used with my computer to monitor the unit. The 10Mhz output from the T-bolt has a BNC jumper to the input of the distribution amplifier that has 3 Q-bit amps & 1 unamplified output that allows me to monitor the output of the T-bolt directly. Here are two photos of the unit I threw together. I think it makes a nice inexpensive GPSDO package. Inside http://farm3.static.flickr.com/2715/4307285530_4222e414ff_o.jpg Front http://farm3.static.flickr.com/2798/4307285448_1921a16b26_o.jpg In the photo of the front of the unit, to the right of the T-bolt, is a RFTG-u Ref 1 (HP Z3811 with a MTI 260 OCXO) that I modified to run correctly without the interface cable and companion Ref 0 unit. That has a nice stable 5Mhz output feeding a FE-7921A 5Mhz distribution amp. I’m using a Philips PM6680 counter with an X72 Rb timebase and aPhilips PM3375 scope for quick frequency checks. Works quite well to compare the 2 GPSDOs. ___ 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] DMTD Question1
Knowing the magnitude of various effects allows one to make rational choices based on one's actual or perceived requirements. Just ignoring effects which may or may not be significant and hoping that they wont be significant isn't particularly rational. The aim was a system noise floor of around 1E-13/SQRT(Tau) (for Tau up to a few hundred seconds at least) or better to ensure that this is well below the expected stability of sources being compared. There are also other uses for DMTD systems such as measuring phase instability of cables etc, that some may wish to pursue. NIST found a mixer phase shift TC of up to 75ps/K for uncompensated mixers with 5MHz inputs. If you carefully analyse your favourite frequency comparison system you may just discover why this particular technique was quietly dropped as not being particularly useful for Tau much greater than the PLL inverse loop bandwidth. The real problem is that there is no simple way to actually determine the actual Tau range for which such a system is useful other than comparing the results obtained with those from a more conventional system. Bruce WarrenS wrote: Bruce OK, Now what am I missing? I understand there are 'Freq nuts' and just 'plane NUTS', this sound like the later. With a little effort, not hard to hold the temp drift rate change to 1deg / hr (and a couple deg change altogether). Lets say the Tempco balance of the mixers was as bad a 1ns / deg That means temp change would add an addition freq error offset term of half of 3e-13 at tau of 3600 sec (36ns/hr = 1e-11) Even this gross amount would not effect the results of most of the things that any of these freq nuts would be testing including probable the best CS or RB Osc. AND if they are doing 1e-15 things, they probable want to be hold the temp to better than 0.01deg for many other reasons as well. So why even talk about TC phase shifts at the ps / deg level? Who cares and who needs it? Does not sound like you are doing the Nuts any service to address things that are orders of Magnitude below usefulness. ws ** - Original Message - From: "Bruce Griffiths" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, January 26, 2010 1:51 AM Subject: Re: [time-nuts] DMTD Question If one carefully the value of a resistor in series with both the mixer RF and LO ports and adds a 6dB attenuator between the series resistor and the output of the associated isolation amplifier its possible to reduce the mixer phase shift tempco by a factor of 10 or so. The resistor value is chosen to minimise the mixer port VSWR for the given IF port termination. At 5Mhz this can reduce the mixer phase shift tempco to less than 5ps/K. The mixer phase shift tempco also reduces as the input frequency increases (at least up to 100Mhz or so) by a factor equal to the ratio of the frequencies for which the phase shift tempco is being compared. Thus carefully matching the mixer inputs can reduce the required mixer temperature stability. It is believed that the matching reduces the effect of reflections in the input cables, so a similar effect may be achieved by using an isolation amplifier located close to each mixer input port. Bruce ___ 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] Conducting Bench Top Material
Everything old is new again. The 25+ year old HP Bench Brief that I referred to a few messages back warns about that. Ed Joe Fitzgerald wrote: I am concerned about static discharges when handling modern semiconductors. These days it's not just semiconductors at risk given the tiny geometry of passives. At work we had a work station where we assembled a board with all passive components, so no thought was given to ESD control. We traced a series of mysterious failures to ESD affecting the value of some resistors. Now ESD control is just about everywhere! -Joe Fitzgerald KM1P ___ 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] ko4bb monitor
Maybe the 70 displays will appear on ePay soon. I'll keep an eye on it. Ignacio Arthur Dent wrote: "Hi I found that warehouse! http://www.liquidation.com/auction/view?id=2954816 I don't know what should be the next step. Ignacio" That auction ended 01-17-2010. If you check the manifest there apparently were only 70 of the LCD display units in the lot and the rest was cables and other parts of the system. The final price seemed to be $1100. ___ 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] Conducting Bench Top Material
> I am concerned about static discharges when > handling modern semiconductors. These days it's not just semiconductors at risk given the tiny geometry of passives. At work we had a work station where we assembled a board with all passive components, so no thought was given to ESD control. We traced a series of mysterious failures to ESD affecting the value of some resistors. Now ESD control is just about everywhere! -Joe Fitzgerald KM1P ___ 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] ko4bb monitor
Hi Now I don't feel so bad. 70 useful displays for $1000 is something I won't worry about missing out on. 1800 displays at 63 cents each, that would have been a shame They are out there though. If we could just find the right auction at the right time !!! Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur Dent Sent: Tuesday, January 26, 2010 12:40 PM To: time-nuts@febo.com Subject: [time-nuts] ko4bb monitor "Hi I found that warehouse! http://www.liquidation.com/auction/view?id=2954816 I don't know what should be the next step. Ignacio" That auction ended 01-17-2010. If you check the manifest there apparently were only 70 of the LCD display units in the lot and the rest was cables and other parts of the system. The final price seemed to be $1100. ___ 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] ko4bb monitor
"Hi I found that warehouse! http://www.liquidation.com/auction/view?id=2954816 I don't know what should be the next step. Ignacio" That auction ended 01-17-2010. If you check the manifest there apparently were only 70 of the LCD display units in the lot and the rest was cables and other parts of the system. The final price seemed to be $1100. ___ 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] ko4bb monitor
Hi I found that warehouse! http://www.liquidation.com/auction/view?id=2954816 I don't know what should be the next step. Ignacio Bob Camp escribió: Hi There's got to be a warehouse full of these somewhere. I suspect that if we could find out where and make a 1K pice group buy they would be a lot cheaper than they are now on Amazon bought one at a time. Bob On Jan 22, 2010, at 9:07 PM, EB4APL wrote: Arthur, These are good news, since it is a standard kind of LCD. According to your other response there is a daughter board that carries the micro which unfortunately is soldered to the display but I think it's nothing that can't be removed if necessary. When I built some PIC based "electronic dials" for boat anchor receivers the most difficult thing was the cabinets, even I recycled some 3 1/2 floppy and "movement detectors" plastic boxes for the task. I was thinking to ask Bob (fluke.l) for some unprogrammed units, but you found a cheaper source. Now I have to figure out to get it shipped to Spain, since Amazon only allows books and videos to be sent overseas. Thanks a lot. Ignacio, EB4APL - Arthur Dent wrote: "I'm considering to buy some of this displays for other projects (even change the micro family), as they have a nice cabinet that sometimes is the most difficult part to build. Could you tell us if they use a common LCD connected to a pcb with the micro, like the Didier design or these are fully integrated in a single pcb? Any picture of the inside would be very appreciated." The display is a HY-2002A-803http://www.ciahk.net/upload/docs/HY-2002A.pdf ___ 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] Oncore UT+ and NTP configuration
Thanks for all the help on this, I have made quite some progress and learned a heap more about freeBSD along the way So far I have rebuilt everything on freebsd 8, I ran into a few issues with oncore related bugs in NTP In particular this one http://lists.freebsd.org/pipermail/freebsd-bugs/2009-December/037544.html Once I got past that with a more up to date version of NTP from the development sources I get to the point where all installs and starts up but the oncore driver does not get used, tailing the log shows the following error Jan 26 15:20:48 ntpd[1248]: ntpd 4.2.7...@1.2108-o Tue Jan 26 13:07:17 UTC 2010 (3) Jan 26 15:20:48 ntpd[1249]: proto: precision = 11.880 usec Jan 26 15:20:48 ntpd[1249]: ONCORE[0]: ONCORE DRIVER -- CONFIGURING Jan 26 15:20:48 ntpd[1249]: ONCORE[0]: state = ONCORE_NO_IDEA Jan 26 15:20:48 ntpd[1249]: ONCORE[0]: SHMEM (size = 3628) is CONFIGURED and available as /var/log/oncore.0 Jan 26 15:20:48 ntpd[1249]: ONCORE[0]: state = ONCORE_CHECK_ID Jan 26 15:20:50 ntpd[1249]: ONCORE[0]: Oncore: Resend @@Cj Jan 26 15:21:22 last message repeated 2 times Jan 26 15:21:38 ntpd[1249]: ONCORE[0]: Oncore: No response from @@Cj, shutting down driver However I am certain that my oncore responds correctly to @@Cj since I have tried this command both via winoncore and TAC is it possible my issues are down to the serial port speed not being set correctly or does the driver take care of this ? Anyone managed to get PHK's rather interesting looking NTPns to build and install ok under freeBSD8? If so any hints on this? A few annoyances I have not satisfactory resolved yet in relation to nanoBSD. these are probably due to my unfamiliarity with BSD in general 1/ ntp is installed by default even with the most minimal of freeBSD installations. it's installed to /usr/sbin & user/bin directories. when I build a lter version from ports it's installed under /usr/local but the nanoBSD script pulls in preference the version form /usr/bin & usr/sbin 2/ the nanaobsd script leaves out my termcap file every time On Fri, 2010-01-22 at 14:51 +1300, Bruce Griffiths wrote: > ntpd.conf fragment (there are subtle differences due to renaming of > serial ports in FreeBSD 8.0) for nanobsd (FreeBSD8.0) attached together > with kernel config file. > > The hints: > hint.atrtc.0.at= > etc > at the end of the net4501.hints file need to be added. > > Bruce > > Bob Camp wrote: > > Hi > > > > Do you remember what the exact setting was to include the RTC driver in the > > kernel? > > > > Bob > > > > > > On Jan 21, 2010, at 7:43 PM, Bruce Griffiths wrote: > > > > > >> Hal Murray wrote: > >> > >>> bruce.griffi...@xtra.co.nz said: > >>> > >>> > Only issue for 8.0 was to ensure the real time clock driver was > enabled or the initial time error would often be too large. > > > >>> There is a command line switch that allows ntpd to start on systems that > >>> have > >>> a bogus initial date/time. > >>> > >>> > From the man page: > > >>> -g, --panicgate > >>>Allow the first adjustment to be Big. This option may > >>>appear an unlimited number of times. > >>> > >>>Normally, ntpd exits with a message to the system log if > >>>the offset exceeds the panic threshold, which is 1000 s > >>>by default. This option allows the time to be set to any > >>>value without restriction; however, this can happen only > >>>once. If the threshold is exceeded after that, ntpd will > >>>exit with a message to the system log. This option can be > >>>used with the -q and -x options. See the tinker configu- > >>>ration file directive for other options. > >>> > >>> > >>> > >>> > >> I was aware of that, but using the real time clock seems to work better > >> for subsequent power on, once the real time clock is set correctly. > >> > >> However with 8.0 the real time clock driver had to be specifically > >> included in the kernel config file whereas in 7.2 it was automatically > >> included. > >> > >> Bruce > >> > >> > >> ___ > >> 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. -- 73 Brendan EI6IZ _
Re: [time-nuts] Conducting Bench Top Material
Dave wrote: Back about 1981, we had piles of 6502s, etc and decide to some "antistatic testing". We put a 40pin ZIF socket into a VIC-20, and then set about trying to fry the uP using carpet, a cat, car seats, etc. The DUT was then put back into the VIC and series of tests run to verify operation. I don't think we ever had a failure. Of course, there may have been some hiding that we missed, but all the static damage I've seen has been pretty severe. That said, I always use a wrist strap and mat if I'm working on something I don't want to break further. Installed components are generally much less vulnerable to ESD than bare parts, because there are leakage paths (both intentional and otherwise) on a circuit board that allow the ESD to flow around the component rather than through it. With a naked part, any ESD to one of its leads has to flow through its other leads or the case of the device, thereby maximizing any damage. 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.
Re: [time-nuts] Conducting Bench Top Material
Hi If you are manually loading up a wire bonder with conventional CMOS chips, ESD damage is a very real thing. You can haul the chip over to a SEM and actually take pictures of he craters you blast in it. Very cool pictures. No cat's, carpets, or Windhurst machines needed. Just normal operators with missing wrist straps will do the trick quite nicely. Bob On Jan 26, 2010, at 2:21 AM, d.sei...@comcast.net wrote: > Back about 1981, we had piles of 6502s, etc and decide to some "antistatic > testing". We put a 40pin ZIF socket into a VIC-20, and then set about trying > to fry the uP using carpet, a cat, car seats, etc. The DUT was then put back > into the VIC and series of tests run to verify operation. I don't think we > ever had a failure. Of course, there may have been some hiding that we > missed, but all the static damage I've seen has been pretty severe. > > That said, I always use a wrist strap and mat if I'm working on something I > don't want to break further. > > -Dave > - Original Message - > From: "Charles P. Steinmetz" > To: "Discussion of precise time and frequency measurement" > > Sent: Monday, January 25, 2010 11:27:11 AM GMT -07:00 US/Canada Mountain > Subject: Re: [time-nuts] Conducting Bench Top Material > > Bruce wrote: > >> Although over the years the non-conductive top has been an asset in >> avoiding short circuits, etc., I am concerned about static discharges when >> handling modern semiconductors. Would it make sense to spray the Masonite >> with a weak copper sulphate or similar solution so as to make the masonite >> slightly conductive, but not so conductive that 155 VAC connections >> could not >> safely rest upon it? Is there a better-suited material that could be used >> to replace the Masonite? > > I notice that many folks who have contributed on this thread use > anti-static benchtops, but I have never found it necessary (and I try > to keep the RH in my house under 45% -- it is generally 20% or less > in the winter). I've been fooling with static-sensitive parts for 35 > years and haven't lost one to static yet. With that perspective, my > preferred benchtop is white Formica with a very, very slightly > pebbled surface. Very durable, including to molten solder, and small > parts show up well. I use rubberized "gunsmith" mats for preventing > scratches to delicate workpieces (these happen to be anti-static, but > that is not why I have them). > > Other bench thoughts: > > Bench depth is very important. I sometimes work on equipment that is > more than 24" deep, so I want at least 30" of clear space in front of > any obstructions (power strips, Variac, test equipment, > whatever). In the past, I used a "flying bridge" over the rear 18" > of a 48"-deep bench to elevate the test equipment, which worked very > well. Now I use 24" deep adjustable wire-rack shelving units behind > a 30" benchtop (As others have pointed out, you can do the same with > equipment racks -- I'm not a fan of rack-mounting test equipment > unless the racks are anchored and everything is on slides, which I > was not prepared to do). I don't have enough shop real estate to > have a permanent access aisle behind the test equipment, so the bench > and racks have large (5") locking polyurethane wheels and can be > pulled out relatively easily for reconfiguration. This provides > plenty of stability for electronic projects, but you wouldn't want to > mount a big vise on the bench and try to bend 1" rebar. For that, I > have a separate metalworking shop. > > Bench height is also important. I prefer a tall bench, suited to > working standing or sitting on an ergonomic stool, so my bench top is > 44" above the floor -- a bit below my standing elbow height. > > Finally, one can never have too many power outlets, or too much > light, in a workshop. Lighting should be arranged so that it doesn't > cause specular reflections from the workpiece or the faces of test equipment. > > Best regards, > > Charles > > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts 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] DMTD Question
If one carefully the value of a resistor in series with both the mixer RF and LO ports and adds a 6dB attenuator between the series resistor and the output of the associated isolation amplifier its possible to reduce the mixer phase shift tempco by a factor of 10 or so. The resistor value is chosen to minimise the mixer port VSWR for the given IF port termination. At 5Mhz this can reduce the mixer phase shift tempco to less than 5ps/K. The mixer phase shift tempco also reduces as the input frequency increases (at least up to 100Mhz or so) by a factor equal to the ratio of the frequencies for which the phase shift tempco is being compared. Thus carefully matching the mixer inputs can reduce the required mixer temperature stability. It is believed that the matching reduces the effect of reflections in the input cables, so a similar effect may be achieved by using an isolation amplifier located close to each mixer input port. Bruce ___ 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.
