Re: [time-nuts] Long period variation of GPS PPS timing?
> It ought to be a bit better than this, but the 10uS PPS width is a bit too > short for a steady timing of centroid through a soundcard at 192k samples/ > sec, I need to stretch the pulse a factor of 10 or so. The PPS on my TBolt was also too short for a PC running Linux/ntpd to catch it. (It works on another system with different hardware.) Here is how I kludged it... >From the TBolt PPS pin: resistor (current limiter) diode cap to ground resistor across cap (decay) I think I used 50 ohms for the current limiting resistor and 0.1 uF for the cap. I forget the value of the other resistor. That's far from symmetric so finding the "centroid" may get interesting and/or may not work at all. I was connecting it to pin 1 (DCD) on the serial port. That's where ntpd expects PPS and it's unused on the TBolt. It all fits on the bottom side of the board inside the TBolt box. Or you could try the FatPPS from TAPR: http://www.tapr.org/kits_fatpps.html Or look at the manual in for ideas. It uses a 74HC123. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 74AC logic differences between manufactures
Probably none, since Fairchild inherited that product line from National Semiconductor. Regards, Javier, EA1CRB El 13/07/2010 21:30, Stanley Reynolds escribió: Learning about the differences between families now know why a 74F is not a substitute for 74AC. But remembering something I read in Brooks Shera, W5OJM GPSDO notes "Take care about which 4046 chips you use for U1 and U3. The Phillips 74HCT4046 chips (formerly sold by Radio Shack) are fine. So are CD74HC4046 chips made by Harris or T.I. Do not use chips made by Fairchild and do not use CD4046 chips; both have a different design and will not work in this circuit." Does anyone know about any differences in Fairchild and National Semiconductor 74AC175PC ? Stanley ___ 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. -- Javier HerreroEMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Long period variation of GPS PPS timing?
Just a follow-up on this. Yesterday I received a Thunderbolt from fluke.l, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290322053618 This worked straight away and has cured the 50 minute drift cycle. I'm getting a standard deviation of pulse interval of about 0.25uS, as measured against the soundcard sample clock. It ought to be a bit better than this, but the 10uS PPS width is a bit too short for a steady timing of centroid through a soundcard at 192k samples/sec, I need to stretch the pulse a factor of 10 or so. The Thunderbolt seems to take about 45 mins to settle down to a steady rate, which is fine. Meanwhile, Garmin wrote to say they will try to reproduce the 50 minute drift on the GPS16X. So that problem is fixed. Thanks for the advice and suggestions. -- Paul Nicholson http://abelian.org -- ___ 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] PIC-TIC boards
Claude, No problem you are on the list, the 74AC175PC is correct chip, not 74ACT175PC. Stanley - Original Message From: Claude Houde To: time-nuts@febo.com Sent: Tue, July 13, 2010 8:15:25 PM Subject: [time-nuts] PIC-TIC boards Hello ! I know I'm a bit late, but is it still possible to order three boards, and have shipped to Canada ? I can program my own PIC's and have access to 74ACT175. Also, I would be willing to program chips for other Time Nuts if it can help someone. Thanks ! 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. ___ 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] PIC-TIC boards
Hello ! I know I'm a bit late, but is it still possible to order three boards, and have shipped to Canada ? I can program my own PIC's and have access to 74ACT175. Also, I would be willing to program chips for other Time Nuts if it can help someone. Thanks ! 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] Any clock disturbances during the July 11solareclipse?
Thanks Ulrich 2 E -10 seems high and a straight line on a double oven is what I would expect, looking at a month or two may tell more. Also what is the change in ambient temperature? With Rubidiums in the less than $100 range I think it is the best bang for a buck. I am still waiting for the final results of the three testers of the Dual Mixer but once it is completed I will test the combination of a M100 with a selected HP 10811 replacing the internal Xtal Osc. and using the 60 second loop of the HP 5061B. Bert In a message dated 7/13/2010 9:42:05 A.M. Eastern Daylight Time, df...@ulrich-bangert.de writes: Bert, I am really unsure whether the drift alone should make me think that the parts are bad. If the drift can be modelled well by the regulation loop (and the Z3805's software seems to do so) it can well be compesated for. Unfortunately even here is no real expert for MTI stuff who could tell us more about MTI stuff. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > Gesendet: Dienstag, 13. Juli 2010 14:42 > An: time-nuts@febo.com > Betreff: Re: [time-nuts] Any clock disturbances during the > July 11solareclipse? > > > Ulrich, > thank you for the info. I think that 2 E-10 per dayis the > best argument > for any Rubidium. > Bert > > > In a message dated 7/13/2010 8:05:25 A.M. Eastern Daylight Time, > df...@ulrich-bangert.de writes: > > Bert, > > lacking a 3805 manual my guess is that the 3805 EFC scale > may be considered the same as the 3801's one. Which would > lead to the conclusion that 1 EFC unit equals roughly > 1.0E-12 of relative frequency change of the LO. > > Symmetricon seems to have believed that the MTI 260 type > double oven OCXOs in the Z3805 are superiour to the 10811 > double oven OCXOs used in the > Z3801. > However, even after months of being in action, their drift > is still very high. If the above assumption is right what you > see in the graph in general is a drift of 2.0E-10 per day. I > do not notice any diurnal changes on the EFC due to > day/night temperature variations which are otherwise the > biggest environmental impact on oscillator frequency > variations. So, despite of the drift the MTI 260 seem to be > very "predictable" beasts which leads to holdover > uncertainities that are mostly way below 1 microsecond for a > 24 h interval. > > Best regards > Ulrich > > > -Ursprungliche Nachricht- > > Von: time-nuts-boun...@febo.com > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > > Gesendet: Dienstag, 13. Juli 2010 12:21 > > An: time-nuts@febo.com > > Betreff: Re: [time-nuts] Any clock disturbances during the > > July 11 solareclipse? > > > > > > Ulrich > > not having a 3805 can you please explain the scale. > > Thank you > > Bert Kehren > > > > > > In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, > > df...@ulrich-bangert.de writes: > > > > Antonio, > > > > attached is a recording of my Z3805's EFC along July 11. > > Times are in UTC. > > > > Best regards > > Ulrich > > > > > -Ursprungliche Nachricht- > > > Von: time-nuts-boun...@febo.com > > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von > iov...@inwind.it > > > Gesendet: Montag, 12. Juli 2010 22:19 > > > An: time-nuts@febo.com > > > Betreff: [time-nuts] Any clock disturbances during the July > > > 11 solar eclipse? > > > > > > > > > > > > Hi all, > > > > > > did anybody out there observe any disturbances in his clocks > > > during (and/or > > > before or after) the July 11 solar eclipse? > > > (due to other duties I've been prevented from doing any tests) > > > > > > Thanks, > > > Antonio I8IOV > > > > > >___ > > > 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 >
Re: [time-nuts] Rubidium oscillator controlled clock
> I understand that you received some negative feedback on your ripple counter > divider circuit but a single resync flipflop on its outputs in front of the > AC04 drivers will do the job. I think it's (much?) more complicated than that. The basic problem is that the 74LS90 is very very slow. Worst case prop times are 50 ns per chip. I don't see a nice clean simple way to fix this. It's not even clear what the goals should be. One possible goal would be to make all the output clocks rise at the same time. A simple FF on each clock before the drivers won't fix that since the prop time through the chain is several clock cycles. Another possible goal would be to reduce jitter and wander. (I'm using "wander" to cover low frequency phase shifts, for example the prop time changing with temperature.) An extra FF clocked by a low-jitter clock will reduce the Gaussian jitter, probably by the square root of the number of clocks in the chain. On the other hand, if the temperature changes by enough so that the delay wanders across a clock edge, you might get "jitter" of a whole cycle as the delay through the chain changes from N cycles to N-1 or N+1. You might be able to avoid the cycle jumps. Suppose you are lucky so that the end of the long ripple to make the 1 HZ clock comes out in the middle of of the clock window. Now all you have to do is keep the temperature and supply voltage stable. If you aren't lucky enough, you can add a delay, either R-C or a buffer chip. This is clearly a kludge, but it might work well enough for a one-shot lab setup. There is another worm in this area. If you are doubly unlucky and your setup wanders near the clock edge, your retiming FF might go metastable. The usual clean solution is 2 FF, but you have to check the goodness of your logic family and compare that to the excess prop time at your clock rate. For my uses, I would probably leave out the extra FF and live with the extra jitter and wander until I needed something better. Then I would at least know what "better" meant for me. YMMV. You can also fix the multi-cycle delay problem by putting a FF (clocked off the 10 MHz clock) between each LS90. That would change the timing from a long ripple to several 1-cycle steps. If you want all the clock edges to rise at the same time, you have to put extra FFs in the faster clocks to delay them the same number of cycles as the slow path. (This is standard pipeline logic. It's easy after you see it, but may not be obvious until you do get it. I'll say more if anybody wants.) Another approach would be to put the whole thing into a CPLD/FPGA/micro. These need tools and the skill to drive them. That's no fun if you don't like that stuff, but can be great if you do. The micro isn't any good for high speeds, but it should work for anything slower than 100 KHz. Sometimes you can use serial ports to make clock/data patterns. Adjust the baud rate to get the speed you want and send a continuous stream of 10101010. That works better when you have a DMA engine that you can feed a big buffer to amortize the buffer-reload logic over lots of bits. (as compared to taking an interrupt on each byte) With multiple clocks in the same chip, the clock-to-out time depends (slightly) on the number of signals that are switching. So for super low jitter, you still want an external FF to clean things up. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 74AC logic differences between manufactures
Hi Without plugging them into a board, you'll never really know which one is better. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Stanley Reynolds Sent: Tuesday, July 13, 2010 3:31 PM To: time-nuts@febo.com Subject: [time-nuts] 74AC logic differences between manufactures Learning about the differences between families now know why a 74F is not a substitute for 74AC. But remembering something I read in Brooks Shera, W5OJM GPSDO notes "Take care about which 4046 chips you use for U1 and U3. The Phillips 74HCT4046 chips (formerly sold by Radio Shack) are fine. So are CD74HC4046 chips made by Harris or T.I. Do not use chips made by Fairchild and do not use CD4046 chips; both have a different design and will not work in this circuit." Does anyone know about any differences in Fairchild and National Semiconductor 74AC175PC ? Stanley ___ 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] 74AC logic differences between manufactures
Learning about the differences between families now know why a 74F is not a substitute for 74AC. But remembering something I read in Brooks Shera, W5OJM GPSDO notes "Take care about which 4046 chips you use for U1 and U3. The Phillips 74HCT4046 chips (formerly sold by Radio Shack) are fine. So are CD74HC4046 chips made by Harris or T.I. Do not use chips made by Fairchild and do not use CD4046 chips; both have a different design and will not work in this circuit." Does anyone know about any differences in Fairchild and National Semiconductor 74AC175PC ? Stanley ___ 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] Chances of 5061 and 5062 still having life in them?
I have suffered greatly from 'CS Addiction' since becoming a time-nut. I have purchased a total of 7 5061A's and 2 5061B's that were complete and 2 additional 5061A's for parts, one of which is missing only the tube and the other missing various components including the tube. I have been able to get all 9 of the complete units working though one has a marginal beam current. Their benefit is an independent primary reference and I have had an absolutely great time learning about these units while getting them working. As someone else said on the list, assume they will not work. Then the gratification of getting them working will be that much greater. Good luck, Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of swingbyte Sent: Tuesday, July 13, 2010 9:46 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Chances of 5061 and 5062 still having life in them? Hi Guys, In Australia some Ce units have hit the surplus market. looks like they are from the 70s - that's 40 years old now. What does the group think the probability of the tubes having any Ce left in them and still working? Is it worth it now when one can use gps clocks to lock say an Rb? Thanks for your thoughts Tim ___ 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] Chances of 5061 and 5062 still having life in them?
Hi I noticed a HP 5061A in Australia with a patek-philippe clock movement on ebay. The clock will be worth some thing, even if the tube is bad! May compensate for the risk you take. Bert Kehren In a message dated 7/13/2010 12:19:58 P.M. Eastern Daylight Time, li...@rtty.us writes: Hi It's quite possible that they have been re-tubed three or four times already. That makes the estimation process pretty tough. Pay for them as if they were dead, feel good if you get a working one. Don't feel bad if you get out-bid... There are indeed things that a Cs can do that a GPS locked Rb can not. Running a Cs 24 hours a day 365 days a year for years and years can be pretty expensive. A lot depends on what you want (or need) to do with it. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of swingbyte Sent: Tuesday, July 13, 2010 10:46 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Chances of 5061 and 5062 still having life in them? Hi Guys, In Australia some Ce units have hit the surplus market. looks like they are from the 70s - that's 40 years old now. What does the group think the probability of the tubes having any Ce left in them and still working? Is it worth it now when one can use gps clocks to lock say an Rb? Thanks for your thoughts Tim ___ 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] PICTIC II PIC chip group order (update)
Hi all, Just a reminder that I'm going to place an order for the PICTIC PIC chips tonight for those in the USA that want them. The price is $10.00 for the first one, $2.50 for each additional, including shipping and programming. 1 would be $10.00 even, 3 would be $15.00, etc. You can PayPal me at rdarling...@gmail.com or cut me a personal check, cash, whatever. Pretty much anything other than livestock! Just make sure I have a good shipping address.I'll order a few extras for stragglers that missed this. Thanks, Bob, N3XKB ___ 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] Any clock disturbances during the July11solareclipse?
On 07/13/2010 06:25 PM, Bob Camp wrote: Hi The 260 in my z3805 also has a very linear drift plot. Mine is positive, but otherwise a lot like the one you show. The plot in both cases indeed remarkably linear. That makes you wonder just what the mechanism is. Since they market the 260 as a "rubidium replacement" it is indeed surprising that the aging does not level off a bit more. Didn't they provide some form of prediction/compensation tricks? If so, maybe it needs some recal after all these years? Thus, they have a systematic offset error somewhere? I think I recall somthing from way back about that... 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] Any clock disturbances during the July11solareclipse?
Hi The 260 in my z3805 also has a very linear drift plot. Mine is positive, but otherwise a lot like the one you show. The plot in both cases indeed remarkably linear. That makes you wonder just what the mechanism is. Since they market the 260 as a "rubidium replacement" it is indeed surprising that the aging does not level off a bit more. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ulrich Bangert Sent: Tuesday, July 13, 2010 9:42 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Any clock disturbances during the July11solareclipse? Bert, I am really unsure whether the drift alone should make me think that the parts are bad. If the drift can be modelled well by the regulation loop (and the Z3805's software seems to do so) it can well be compesated for. Unfortunately even here is no real expert for MTI stuff who could tell us more about MTI stuff. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > Gesendet: Dienstag, 13. Juli 2010 14:42 > An: time-nuts@febo.com > Betreff: Re: [time-nuts] Any clock disturbances during the > July 11solareclipse? > > > Ulrich, > thank you for the info. I think that 2 E-10 per dayis the > best argument > for any Rubidium. > Bert > > > In a message dated 7/13/2010 8:05:25 A.M. Eastern Daylight Time, > df...@ulrich-bangert.de writes: > > Bert, > > lacking a 3805 manual my guess is that the 3805 EFC scale > may be considered the same as the 3801's one. Which would > lead to the conclusion that 1 EFC unit equals roughly > 1.0E-12 of relative frequency change of the LO. > > Symmetricon seems to have believed that the MTI 260 type > double oven OCXOs in the Z3805 are superiour to the 10811 > double oven OCXOs used in the > Z3801. > However, even after months of being in action, their drift > is still very high. If the above assumption is right what you > see in the graph in general is a drift of 2.0E-10 per day. I > do not notice any diurnal changes on the EFC due to > day/night temperature variations which are otherwise the > biggest environmental impact on oscillator frequency > variations. So, despite of the drift the MTI 260 seem to be > very "predictable" beasts which leads to holdover > uncertainities that are mostly way below 1 microsecond for a > 24 h interval. > > Best regards > Ulrich > > > -Ursprungliche Nachricht- > > Von: time-nuts-boun...@febo.com > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > > Gesendet: Dienstag, 13. Juli 2010 12:21 > > An: time-nuts@febo.com > > Betreff: Re: [time-nuts] Any clock disturbances during the > > July 11 solareclipse? > > > > > > Ulrich > > not having a 3805 can you please explain the scale. > > Thank you > > Bert Kehren > > > > > > In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, > > df...@ulrich-bangert.de writes: > > > > Antonio, > > > > attached is a recording of my Z3805's EFC along July 11. > > Times are in UTC. > > > > Best regards > > Ulrich > > > > > -Ursprungliche Nachricht- > > > Von: time-nuts-boun...@febo.com > > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von > iov...@inwind.it > > > Gesendet: Montag, 12. Juli 2010 22:19 > > > An: time-nuts@febo.com > > > Betreff: [time-nuts] Any clock disturbances during the July > > > 11 solar eclipse? > > > > > > > > > > > > Hi all, > > > > > > did anybody out there observe any disturbances in his clocks > > > during (and/or > > > before or after) the July 11 solar eclipse? > > > (due to other duties I've been prevented from doing any tests) > > > > > > Thanks, > > > Antonio I8IOV > > > > > > ___ > > > 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 f
Re: [time-nuts] Chances of 5061 and 5062 still having life in them?
Hi It's quite possible that they have been re-tubed three or four times already. That makes the estimation process pretty tough. Pay for them as if they were dead, feel good if you get a working one. Don't feel bad if you get out-bid... There are indeed things that a Cs can do that a GPS locked Rb can not. Running a Cs 24 hours a day 365 days a year for years and years can be pretty expensive. A lot depends on what you want (or need) to do with it. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of swingbyte Sent: Tuesday, July 13, 2010 10:46 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Chances of 5061 and 5062 still having life in them? Hi Guys, In Australia some Ce units have hit the surplus market. looks like they are from the 70s - that's 40 years old now. What does the group think the probability of the tubes having any Ce left in them and still working? Is it worth it now when one can use gps clocks to lock say an Rb? Thanks for your thoughts Tim ___ 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] 74AC175PC Update
Hi All As of 17:07 BST, 13th July, all of the 32 available 74AC175PCs have been spoken for, assuming all who've expressed an interest go ahead. If anyone drops out I'll post accordingly, otherwise will contact those on my list again once I have the ICs to hand and have confirmed delivery costs etc. regards Nigel GM8PZR ___ 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] Chances of 5061 and 5062 still having life in them?
I would guess it revolves around the cost. Impossible to say if any CS is left. But for cheap it may be worth trying. But then shipping will most likely get you. I do agree GPS locked RB is a very nice way to go. At least in the US various RB references much newer in age with possibly more life show up on epay all the time. I have an older hp5065 RB that still working like a champ those must be at least 30 years. Good luck On Tue, Jul 13, 2010 at 10:45 AM, swingbyte wrote: > Hi Guys, > In Australia some Ce units have hit the surplus market. looks like they > are from the 70s - that's 40 years old now. What does the group think the > probability of the tubes having any Ce left in them and still working? Is > it worth it now when one can use gps clocks to lock say an Rb? > > Thanks for your thoughts > > Tim > > ___ > 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] Chances of 5061 and 5062 still having life in them?
Hi Guys, In Australia some Ce units have hit the surplus market. looks like they are from the 70s - that's 40 years old now. What does the group think the probability of the tubes having any Ce left in them and still working? Is it worth it now when one can use gps clocks to lock say an Rb? Thanks for your thoughts Tim ___ 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] Any clock disturbances during the July 11solareclipse?
Bert, I am really unsure whether the drift alone should make me think that the parts are bad. If the drift can be modelled well by the regulation loop (and the Z3805's software seems to do so) it can well be compesated for. Unfortunately even here is no real expert for MTI stuff who could tell us more about MTI stuff. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > Gesendet: Dienstag, 13. Juli 2010 14:42 > An: time-nuts@febo.com > Betreff: Re: [time-nuts] Any clock disturbances during the > July 11solareclipse? > > > Ulrich, > thank you for the info. I think that 2 E-10 per dayis the > best argument > for any Rubidium. > Bert > > > In a message dated 7/13/2010 8:05:25 A.M. Eastern Daylight Time, > df...@ulrich-bangert.de writes: > > Bert, > > lacking a 3805 manual my guess is that the 3805 EFC scale > may be considered the same as the 3801's one. Which would > lead to the conclusion that 1 EFC unit equals roughly > 1.0E-12 of relative frequency change of the LO. > > Symmetricon seems to have believed that the MTI 260 type > double oven OCXOs in the Z3805 are superiour to the 10811 > double oven OCXOs used in the > Z3801. > However, even after months of being in action, their drift > is still very high. If the above assumption is right what you > see in the graph in general is a drift of 2.0E-10 per day. I > do not notice any diurnal changes on the EFC due to > day/night temperature variations which are otherwise the > biggest environmental impact on oscillator frequency > variations. So, despite of the drift the MTI 260 seem to be > very "predictable" beasts which leads to holdover > uncertainities that are mostly way below 1 microsecond for a > 24 h interval. > > Best regards > Ulrich > > > -Ursprungliche Nachricht- > > Von: time-nuts-boun...@febo.com > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > > Gesendet: Dienstag, 13. Juli 2010 12:21 > > An: time-nuts@febo.com > > Betreff: Re: [time-nuts] Any clock disturbances during the > > July 11 solareclipse? > > > > > > Ulrich > > not having a 3805 can you please explain the scale. > > Thank you > > Bert Kehren > > > > > > In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, > > df...@ulrich-bangert.de writes: > > > > Antonio, > > > > attached is a recording of my Z3805's EFC along July 11. > > Times are in UTC. > > > > Best regards > > Ulrich > > > > > -Ursprungliche Nachricht- > > > Von: time-nuts-boun...@febo.com > > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von > iov...@inwind.it > > > Gesendet: Montag, 12. Juli 2010 22:19 > > > An: time-nuts@febo.com > > > Betreff: [time-nuts] Any clock disturbances during the July > > > 11 solar eclipse? > > > > > > > > > > > > Hi all, > > > > > > did anybody out there observe any disturbances in his clocks > > > during (and/or > > > before or after) the July 11 solar eclipse? > > > (due to other duties I've been prevented from doing any tests) > > > > > > Thanks, > > > Antonio I8IOV > > > > > > ___ > > > 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. ___ 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] Any clock disturbances during the July11solareclipse?
Joe, it is called Z38XX and is a windows tool which can be used to monitor the whole Z38 family where its name comes from. I wrote it about a year ago. You can download it free from http://www.ulrich-bangert.de/html/downloads.html It connects direcly to the Z3805's RS232 connector via a null-modem cable. Murray Greenman, another member of time nuts, has written a nice manual for it (included in the zip) so that you should not have big difficulties to get it run. Best regards Ulrich Bangert > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von J. L. Trantham > Gesendet: Dienstag, 13. Juli 2010 14:11 > An: 'Discussion of precise time and frequency measurement' > Betreff: Re: [time-nuts] Any clock disturbances during the > July11solareclipse? > > > Ulrich, > > What software do you use to monitor your 3805A and how do you > connect to it? > > Joe > > -Original Message- > From: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] On Behalf Of Ulrich Bangert > Sent: Tuesday, July 13, 2010 7:05 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] Any clock disturbances during the > July 11solareclipse? > > > Bert, > > lacking a 3805 manual my guess is that the 3805 EFC scale may > be considered the same as the 3801's one. Which would lead to > the conclusion that 1 EFC unit equals roughly 1.0E-12 of > relative frequency change of the LO. > > Symmetricon seems to have believed that the MTI 260 type > double oven OCXOs in the Z3805 are superiour to the 10811 > double oven OCXOs used in the Z3801. However, even after > months of being in action, their drift is still very high. If > the above assumption is right what you see in the graph in > general is a drift of 2.0E-10 per day. I do not notice any > diurnal changes on the EFC due to day/night temperature > variations which are otherwise the biggest environmental > impact on oscillator frequency variations. So, despite of the > drift the MTI 260 seem to be very "predictable" beasts which > leads to holdover uncertainities that are mostly way below 1 > microsecond for a 24 h interval. > > Best regards > Ulrich > > > -Ursprungliche Nachricht- > > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im > > Auftrag von ewkeh...@aol.com > > Gesendet: Dienstag, 13. Juli 2010 12:21 > > An: time-nuts@febo.com > > Betreff: Re: [time-nuts] Any clock disturbances during the > > July 11 solareclipse? > > > > > > Ulrich > > not having a 3805 can you please explain the scale. > > Thank you > > Bert Kehren > > > > > > In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, > > df...@ulrich-bangert.de writes: > > > > Antonio, > > > > attached is a recording of my Z3805's EFC along July 11. > Times are in > > UTC. > > > > Best regards > > Ulrich > > > > > -Ursprungliche Nachricht- > > > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] > > > Im Auftrag von iov...@inwind.it > > > Gesendet: Montag, 12. Juli 2010 22:19 > > > An: time-nuts@febo.com > > > Betreff: [time-nuts] Any clock disturbances during the July > > > 11 solar eclipse? > > > > > > > > > > > > Hi all, > > > > > > did anybody out there observe any disturbances in his > clocks during > > > (and/or before or after) the July 11 solar eclipse? > > > (due to other duties I've been prevented from doing any tests) > > > > > > Thanks, > > > Antonio I8IOV > > > > > > ___ > > > 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. ___ 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] Any clock disturbances during the July 11 solareclipse?
Ulrich, thank you for the info. I think that 2 E-10 per dayis the best argument for any Rubidium. Bert In a message dated 7/13/2010 8:05:25 A.M. Eastern Daylight Time, df...@ulrich-bangert.de writes: Bert, lacking a 3805 manual my guess is that the 3805 EFC scale may be considered the same as the 3801's one. Which would lead to the conclusion that 1 EFC unit equals roughly 1.0E-12 of relative frequency change of the LO. Symmetricon seems to have believed that the MTI 260 type double oven OCXOs in the Z3805 are superiour to the 10811 double oven OCXOs used in the Z3801. However, even after months of being in action, their drift is still very high. If the above assumption is right what you see in the graph in general is a drift of 2.0E-10 per day. I do not notice any diurnal changes on the EFC due to day/night temperature variations which are otherwise the biggest environmental impact on oscillator frequency variations. So, despite of the drift the MTI 260 seem to be very "predictable" beasts which leads to holdover uncertainities that are mostly way below 1 microsecond for a 24 h interval. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > Gesendet: Dienstag, 13. Juli 2010 12:21 > An: time-nuts@febo.com > Betreff: Re: [time-nuts] Any clock disturbances during the > July 11 solareclipse? > > > Ulrich > not having a 3805 can you please explain the scale. > Thank you > Bert Kehren > > > In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, > df...@ulrich-bangert.de writes: > > Antonio, > > attached is a recording of my Z3805's EFC along July 11. > Times are in UTC. > > Best regards > Ulrich > > > -Ursprungliche Nachricht- > > Von: time-nuts-boun...@febo.com > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von iov...@inwind.it > > Gesendet: Montag, 12. Juli 2010 22:19 > > An: time-nuts@febo.com > > Betreff: [time-nuts] Any clock disturbances during the July > > 11 solar eclipse? > > > > > > > > Hi all, > > > > did anybody out there observe any disturbances in his clocks > > during (and/or > > before or after) the July 11 solar eclipse? > > (due to other duties I've been prevented from doing any tests) > > > > Thanks, > > Antonio I8IOV > > > > ___ > > 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] Any clock disturbances during the July 11solareclipse?
Ulrich, What software do you use to monitor your 3805A and how do you connect to it? Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ulrich Bangert Sent: Tuesday, July 13, 2010 7:05 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Any clock disturbances during the July 11solareclipse? Bert, lacking a 3805 manual my guess is that the 3805 EFC scale may be considered the same as the 3801's one. Which would lead to the conclusion that 1 EFC unit equals roughly 1.0E-12 of relative frequency change of the LO. Symmetricon seems to have believed that the MTI 260 type double oven OCXOs in the Z3805 are superiour to the 10811 double oven OCXOs used in the Z3801. However, even after months of being in action, their drift is still very high. If the above assumption is right what you see in the graph in general is a drift of 2.0E-10 per day. I do not notice any diurnal changes on the EFC due to day/night temperature variations which are otherwise the biggest environmental impact on oscillator frequency variations. So, despite of the drift the MTI 260 seem to be very "predictable" beasts which leads to holdover uncertainities that are mostly way below 1 microsecond for a 24 h interval. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > Gesendet: Dienstag, 13. Juli 2010 12:21 > An: time-nuts@febo.com > Betreff: Re: [time-nuts] Any clock disturbances during the > July 11 solareclipse? > > > Ulrich > not having a 3805 can you please explain the scale. > Thank you > Bert Kehren > > > In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, > df...@ulrich-bangert.de writes: > > Antonio, > > attached is a recording of my Z3805's EFC along July 11. > Times are in UTC. > > Best regards > Ulrich > > > -Ursprungliche Nachricht- > > Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] > > Im Auftrag von iov...@inwind.it > > Gesendet: Montag, 12. Juli 2010 22:19 > > An: time-nuts@febo.com > > Betreff: [time-nuts] Any clock disturbances during the July > > 11 solar eclipse? > > > > > > > > Hi all, > > > > did anybody out there observe any disturbances in his clocks during > > (and/or before or after) the July 11 solar eclipse? > > (due to other duties I've been prevented from doing any tests) > > > > Thanks, > > Antonio I8IOV > > > > ___ > > 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] Any clock disturbances during the July 11 solareclipse?
Bert, lacking a 3805 manual my guess is that the 3805 EFC scale may be considered the same as the 3801's one. Which would lead to the conclusion that 1 EFC unit equals roughly 1.0E-12 of relative frequency change of the LO. Symmetricon seems to have believed that the MTI 260 type double oven OCXOs in the Z3805 are superiour to the 10811 double oven OCXOs used in the Z3801. However, even after months of being in action, their drift is still very high. If the above assumption is right what you see in the graph in general is a drift of 2.0E-10 per day. I do not notice any diurnal changes on the EFC due to day/night temperature variations which are otherwise the biggest environmental impact on oscillator frequency variations. So, despite of the drift the MTI 260 seem to be very "predictable" beasts which leads to holdover uncertainities that are mostly way below 1 microsecond for a 24 h interval. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von ewkeh...@aol.com > Gesendet: Dienstag, 13. Juli 2010 12:21 > An: time-nuts@febo.com > Betreff: Re: [time-nuts] Any clock disturbances during the > July 11 solareclipse? > > > Ulrich > not having a 3805 can you please explain the scale. > Thank you > Bert Kehren > > > In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, > df...@ulrich-bangert.de writes: > > Antonio, > > attached is a recording of my Z3805's EFC along July 11. > Times are in UTC. > > Best regards > Ulrich > > > -Ursprungliche Nachricht- > > Von: time-nuts-boun...@febo.com > > [mailto:time-nuts-boun...@febo.com] Im Auftrag von iov...@inwind.it > > Gesendet: Montag, 12. Juli 2010 22:19 > > An: time-nuts@febo.com > > Betreff: [time-nuts] Any clock disturbances during the July > > 11 solar eclipse? > > > > > > > > Hi all, > > > > did anybody out there observe any disturbances in his clocks > > during (and/or > > before or after) the July 11 solar eclipse? > > (due to other duties I've been prevented from doing any tests) > > > > Thanks, > > Antonio I8IOV > > > > ___ > > 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] Any clock disturbances during the July 11 solar eclipse?
Ulrich not having a 3805 can you please explain the scale. Thank you Bert Kehren In a message dated 7/13/2010 6:12:47 A.M. Eastern Daylight Time, df...@ulrich-bangert.de writes: Antonio, attached is a recording of my Z3805's EFC along July 11. Times are in UTC. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von iov...@inwind.it > Gesendet: Montag, 12. Juli 2010 22:19 > An: time-nuts@febo.com > Betreff: [time-nuts] Any clock disturbances during the July > 11 solar eclipse? > > > > Hi all, > > did anybody out there observe any disturbances in his clocks > during (and/or > before or after) the July 11 solar eclipse? > (due to other duties I've been prevented from doing any tests) > > Thanks, > Antonio I8IOV > > ___ > 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] Any clock disturbances during the July 11 solar eclipse?
Antonio, attached is a recording of my Z3805's EFC along July 11. Times are in UTC. Best regards Ulrich > -Ursprungliche Nachricht- > Von: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] Im Auftrag von iov...@inwind.it > Gesendet: Montag, 12. Juli 2010 22:19 > An: time-nuts@febo.com > Betreff: [time-nuts] Any clock disturbances during the July > 11 solar eclipse? > > > > Hi all, > > did anybody out there observe any disturbances in his clocks > during (and/or > before or after) the July 11 solar eclipse? > (due to other duties I've been prevented from doing any tests) > > Thanks, > Antonio I8IOV > > ___ > 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. July11.pdf Description: Adobe PDF document ___ 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] 74AC175PC Update
Hi All As of 09:40 BST, 13th July, 29 of the 32 available 74AC175PCs have been spoken for, assuming all who've expressed an interest go ahead. As far as I'm aware I've confirmed directly with all who have so far asked to be included. If you've emailed me and not yet had a reply please try again. regards Nigel GM8PZR ___ 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.
