Re: [time-nuts] 4046 replacement
I too would recommend the 74HCT9046A instead of the 4046. The data sheet is here; https://assets.nexperia.com/documents/data-sheet/74HCT9046A.pdf *Ms. Tisha Hayes* On Wed, Apr 18, 2018 at 8:27 AM, Bob kb8tq <kb...@n1k.org> wrote: > Hi > > If this is a new build, why use a 4046 in the first place? There are many > newer parts > that will do all sorts of things. If this is a repair of something that > has been running > for years, is it > 5V supply to the chips? If so, you are pretty much > stuck with 4000 > series CMOS. > > There are no fatal flaws in the 4046, but there are basic design > limitations. Those > have been well documented over the years and here on the list. Going to a > better > part is the answer for that stuff ( = get away from any 4046 IC). > > Bob > > > On Apr 18, 2018, at 4:04 AM, donald collie <donaldbcol...@gmail.com> > wrote: > > > > I have 4 frequency synthesiser projects, each using HEF4046BCN`s, but > have > > recently read that this CMOS IC has a design flaw. What would be a better > > chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it > > doesn`t have the same bug], or a 74HC7046AN - which is similar. Both > these > > chips are more-or-less pin compatable TIA for any > > advice!. > ..Don > > > > <http://www.avg.com/email-signature?utm_medium=email; > utm_source=link_campaign=sig-email_content=webmail> > > Virus-free. > > www.avg.com > > <http://www.avg.com/email-signature?utm_medium=email; > utm_source=link_campaign=sig-email_content=webmail> > > <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > ___ > > 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] Cheap jitter measurements
" I appreciate that the clock-blessed may have doubts about the truth of his sources. But the fact is, you need a larger sample size to better estimate error. The man who is happy in his ignorance has not considered that calibrated doubt can be more satisfying than unjustified certainty." Just like being trapped in a speeding car with the in-laws; Time is relative. And even if you are in a localized frame of reference it never goes faster. *Ms. Tisha Hayes* On Sun, Apr 8, 2018 at 9:18 PM, Adrian Godwin <artgod...@gmail.com> wrote: > That may be an article of faith for those who haven't experienced the > delights of time-nuttery, but to be fair, the man with n<2 clocks doesn't > know what time it is either. Even if n=1, he only believes he knows what > time it is. > > I appreciate that the clock-blessed may have doubts about the truth of his > sources. But the fact is, you need a larger sample size to better estimate > error. The man who is happy in his ignorance has not considered that > calibrated doubt can be more satisfying than unjustified certainty. > > > On Sun, Apr 8, 2018 at 11:01 PM, Dana Whitlow <k8yumdoo...@gmail.com> > wrote: > > > Pity the poor man who has (n>1) clocks, for he knows not what time it is. > > > > Dana > > > > > > 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] Environmental sensor recommendations
I would suggest that if you are looking at taking temperature sensor data and attempting to control some type of heating/cooling device that you implement a PID loop for stability. https://www.crossco.com/blog/basics-tuning-pid-loops Many simplistic approaches use an ON-OFF controller to turn on cooling or heaters. These can make your stability problems worse than if you just wrapped things up in an insulating blanket. You end up cycling from one extreme to the next. PID loops when properly tuned will vary the speed, current or duty cycle as the temperature approaches a set-point. This avoids overshoot and gives much finer control over the temperature. We used to use 4 wire platinum probes to measure temperature down to the hundredth of a degree. Then for control of the heater element we had a PWM (pulse width modulated) supply. Once the loop was tuned (to minimize positive feedback that causes increasingly crazy oscillations in temperature while at the same time settling in once the temperature soaked through the mass) we could hold a set-point through some wild external temperature extremes. There are software implementations of PID (Proportional, Integral, Derivative) that are pretty easy to understand. There are also surplus temperature controllers on eBay that can accomplish the same thing. *Ms. Tisha Hayes, AA4HA* ___ 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] Repairs and mods underway on HP 3586b
Bob, Thanks so much, as soon as I saw the key sequence I knew where that was going! If only more manufacturers had a sense of humor. We had a test-jig in our development lab that would go through a repeating sequence and spit out a text string for each step it completed; "It slices" *BEEP* "It dices"*BEEP* "It will cut a cow in half" "BEEP,BEEP* -ad infinitum After that ran for a couple of days straight our engineering manager made us move the jig to a room far far away from his office. Tisha *Ms. Tisha Hayes* On Tue, Apr 3, 2018 at 11:14 PM, Bob Darlington <rdarling...@gmail.com> wrote: > Tisha, > > Magnus encouraged me to share my "Happy Easter" with you, or at least this > demo that's kinda like an easter egg: > > https://www.youtube.com/watch?v=8MZpnVs6CWc > > Enjoy, all. > > On Sun, Apr 1, 2018 at 8:24 PM, Tisha Hayes <tisha.ha...@gmail.com> wrote: > > > Thanks to those who responded to my requests off-list for details on > > correcting a partially functional HP 3586b. Here is where I am at with > it; > > > > Replaced the incandescent lamp inside of the 5060-0329 rotary encoder > for a > > white LED with a resistor to work at 5VDC. > > Ordered a 75 ohm BNC chassis jack > > Installed two BNC-SMB cables for the 50 MHz connections that are normally > > covered with blank plugs on the back panel > > Removed all of the buttons and soaked them for a few hours in a mixture > of > > hydrogen peroxide and oxy-clean to remove the brownish oxidation > > (in the process) of pulling the little wafer springs out of each switch > and > > rotating the metal around 180 degrees so the buttons do not need to make > a > > hard "click" > > replaced the NiCad battery with an NiMH > > > > The unit already had the 10 MHz precision oscillator module (thanks to > > Perry Sandeen for that). > > > > I have a couple of Rb standards that are already used for metrology > > (spec-an's, tracking generators, R-590 and a couple of other receivers). > I > > will probably stick with those as frequency references as they are > usually > > running for days at a time. > > > > *Ms. Tisha Hayes, AA4HA* > > ___ > > 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] quartz / liquid nitrogen
You also run in to mechanical vibration issues from the cooling system. At the temperatures involved you are looking at something like a Stirling cycle cooler. Here is a good article; https://arxiv.org/pdf/1309.5445.pdf Maintaining a very stable temperature probably has a much greater impact. Tisha Hayes, AA4HA *Ms. Tisha Hayes* On Mon, Apr 2, 2018 at 2:58 PM, Poul-Henning Kamp <p...@phk.freebsd.dk> wrote: > > In message <299B45118C9248498D7B4F3AFE72231E@pc52>, "Tom Van Baak" writes: > > >Has anyone tried running a quartz oscillator at liquid nitrogen > >temperatures: -196 C (-321F, 77K)? It's probably impractical > >commercially, but maybe something of value to a time nut. > > Whispering gallery sapphire resonators at cryogenic temperatures > is a thing for phase-noise, but those are dielectric (microwave) > resonators, not piezoelectric resonators. > > > Would that dramatically lower temperature improve phase noise & > > short-term performance? > > Yes it will reduce your thermal noise as a source of PN, and > dramatically so. > > But I doubt short and long term performance will improve. > > Even if you can find a zero-turnover cut at a convenient temperature, > I don't think anybody know how to produce mK temperature *stability* > at cryogenic temperatures ? > > -- > 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.
[time-nuts] GPS antenna gain
I had the misfortune of using those very PCTEL antennas in a timing application and excessive gain was a problem with the loss of frame sync whenever the receiver had too much signal from any satellite. It was a highly intermittent problem that appeared every few days; always after I had tested and verified things were working, a failure would happen in the middle of the night, the day after I flew home. Of course I had made all of the "terrible choices" of making sure that the antennas had a clear shot to the sky and coax cable lengths were minimized to reduce loss. After a few weeks of fighting the issue the solution ended up being 10 dB attenuators that could pass DC bias. The WiMAX radio manufacturer initially insisted that I ordered third-party GPS timing antennas from somewhere and ignored (their not documented) specification. It got ugly until I provided the invoice showing that I bought those over-amped up antennas from them, right out of their parts list. I still have a few of those antennas floating around here in the house. *Ms. Tisha Hayes, AA4HA* ___ 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] Repairs and mods underway on HP 3586b
Thanks to those who responded to my requests off-list for details on correcting a partially functional HP 3586b. Here is where I am at with it; Replaced the incandescent lamp inside of the 5060-0329 rotary encoder for a white LED with a resistor to work at 5VDC. Ordered a 75 ohm BNC chassis jack Installed two BNC-SMB cables for the 50 MHz connections that are normally covered with blank plugs on the back panel Removed all of the buttons and soaked them for a few hours in a mixture of hydrogen peroxide and oxy-clean to remove the brownish oxidation (in the process) of pulling the little wafer springs out of each switch and rotating the metal around 180 degrees so the buttons do not need to make a hard "click" replaced the NiCad battery with an NiMH The unit already had the 10 MHz precision oscillator module (thanks to Perry Sandeen for that). I have a couple of Rb standards that are already used for metrology (spec-an's, tracking generators, R-590 and a couple of other receivers). I will probably stick with those as frequency references as they are usually running for days at a time. *Ms. Tisha Hayes, AA4HA* ___ 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] TV Signals as a frequency reference
It might of been fairly easy to use an old NTSC television signal as a frequency reference (lumina, chroma or audio carriers). Now that it is converted over to ATSC it would be much more difficult to recover a reference frequency using readily available electronics. You would have a much better chance of locking on to a commercial FM carrier (88-108 MHz). Some are quite accurate with less than 0.5 Hz of error. If you want both time and frequency then a GPS source is your best bet. You can get something like a ebay surplus Trimble Thunderbolt for less than $150. Tisha Hayes, AA4HA *Ms. Tisha Hayes* On Fri, Mar 30, 2018 at 5:13 PM, Hal Murray <hmur...@megapathdsl.net> wrote: > > fgr...@otiengineering.com said: > > Now that analog TV has gone away, so > > have these signals. > > What do the local TV stations use for a frequency reference? > > Are there low cost receivers that also produce a good reference frequency? > > > -- > These are my opinions. 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. > ___ 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] Introduction, new list member, Ms Tisha Hayes, AA4HA
Greetings to all of the time-nuts on this list. I too have an interest (obsession?) with precision frequency measurement. I have known, visited and had dinner with Perry Sandeen (also a list member) while he lived in Tennessee where we shared a common interest in the beloved R-390A receiver and test equipment. Perry and I would make our pilgrimages to the Huntsville Ham Fest and usually I ended up buying equipment from him. One of the items he sent my way was an HP 3586B that I am finally beginning to put to use. I am trying to find out how to fix the tuning control on the HP3586B and that led me back to this list. If anyone has suggestions on making repairs I would appreciate the info; I am very capable of troubleshooting and making component level repairs, even if I have to take the tuning control apart to fix the optical chopper light source. *Ms. Tisha Hayes, AA4HA* *(Senior Engineer with 4RF USA)* *Gadsden, Alabama* ___ 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.
