[time-nuts] Frequency Mixers

The latest Technical Article from Analog Devices may be of interest to some of you - https://www.analog.com/en/technical-articles/the-changing-landscape-frequency-mixing-components.html?ADICID=EMAL_WW_P354759_MIX-NL-PN_1077=DM23404 John ___

[time-nuts] Re: GPSDO - GPS1300-10-1000 by RFX Ltd. UK

Thank you all for your comments both here and direct, greatly appreciated. I think I now have a more sensible plan. Running LH on a PI as a stand-alone device sounds interesting. If there are project details around, I would be interested in a copy, thanks. John

[time-nuts] Re: GPSDO - GPS1300-10-1000 by RFX Ltd. UK

>Bob said - " A GPSDO with a poor sky view will not do well" Thanks for the feedback. I am exactly 100 miles South of Hadrian's wall and a smidgeon West of The Prime Meridian. My house is in pretty clear surroundings except for a large willow tree in the front garden, which faces South. I can

[time-nuts] Re: GPSDO - GPS1300-10-1000 by RFX Ltd. UK

David - thanks for the reply, but these seem designed for SDR and I wanted 1pps. Nice and cheap though. Paul - thanks too; it seems that you are saying that the performance of all GPSDOs are the same, but that wasn't the impression I had got from listening to discussion here. Fine when the

[time-nuts] GPSDO - GPS1300-10-1000 by RFX Ltd. UK

With all this interesting talk about - a) How hard it was to build a GPSDO from scratch and b) How, to measure a signal accurately, you need a reference circa 10x better I started to get worried since I want to do both. To help with the latter I have acquired an HP5370A that just needs picking

[time-nuts] Tonga effect on GPS

Someone suggested this a while ago, this may be of interest - https://phys.org/news/2022-02-tonga-eruption-ripples-earth-ionosphere.html John ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to

[time-nuts] Time ball clock

What a project! 86,400 x 16 foot columns spaced 3” apart arranged on a cylinder 3.9 miles in diameter with bigger balls for minutes and bigger still for hours. Magical, and almost as grand as the 10,000 year clock. I will raise a Kickstarter Project immediately ... Seriously though, a small

[time-nuts] Re: A Nice Slice of History

The Link worked fine for me, thanks Nigel, just took a while for all those pages. On Page 232 there is information on crystals with two sets of electrodes, common on the low frequency bar crystals that I have quite a few of, and a few others on this list have a few stashed away. The following

[time-nuts] Hermetic tantalum capacitors

When I was a lad designing telecom kit that had a minimum design life of 20 years, we used Sprague tantalum cased glass sealed capacitors that were treated like gold dust. Sprague has now been subsumed into Vishay and they still do the same devices, stocked by Mouser and Digikey at reasonable

[time-nuts] Re: in-ground clock room - geophones

Poul-Henning Kamp writes: "There are a number of footnotes about geophones, the primary one being that they have a resonance frequency in the 4-7 Hz range and therefore provide no usable information below that. The second is that it is anyones guess what their sensitivity is, in particular if

[time-nuts] Missing links

Hello All Thanks for your feedback. I now believe it is because I use the digest-mode option to view all these e-mails and TVB and JA are having a little trouble with the latest update to the system. I will change to the other option and see if the links re-appear. John

[time-nuts] RE - before time was invented (Jan Boutsen)

Is it just me, or has something happened to the links to attachments that people are adding to their posts? It used to be that there was a message saying something had been removed, but there was then a link at the end of the post to retrieve the attachment. The 'removed' messages are still

[time-nuts] Re: Best frequency to start for GHz synth ?

Since low phase noise seems to be a main requirement here, this paper by Jeremy Everard from York University may be of interest - 'Ultralow Phase Noise 10-MHz Crystal Oscillators' Available here - https://ieeexplore.ieee.org/document/8540461 It also shows construction of a double oven system

Re: [time-nuts] Old Crystal.

Ref. the original comment about a blue glow seen in a crystal, I would suggest that it was simply a blue LED used in exactly the same way that constructers of Nixie Clocks add LEDs under the Nixie tubes to make them look more dramatic. John ___

Re: [time-nuts] Daft idea with the National Grid

That was some heavy-weight receptionist! :-) Thanks for the feedback. John > On 8 Feb 2021, at 17:58, Poul-Henning Kamp wrote: > > ---- > John Moran, Scawby Design writes: > >> "If you happen to own something like a steel mill running electric >> >>

Re: [time-nuts] Daft idea with the National Grid

On Sun, 7 Feb 2021 20:45:57 -0800 Jim Lux said - "If you happen to own something like a steel mill running electric furnaces or an aluminum refinery, so you can manipulate the load..." Sometime in the late '80s, my first decent sized computer system came on line at a telecom factory in

Re: [time-nuts] Long Wave Radio-Frequency standard testing

There is an earlier NIST publication on the problems here - https://nvlpubs.nist.gov/nistpubs/jres/64D/jresv64Dn3p239_A1b.pdf John ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

[time-nuts] Technical information on Peltier Modules

Following earlier discussions on the pros and cons of Peltier modules for temperature control of crystal oscillators, DigiKey have just launched a range of small devices. However, the reason for posting that information here is that their web page contains a wealth of information on the

[time-nuts] SiTime Stratum 3E DCOCXO

Does anyone have any knowledge of the suitability of these silicon vs quartz frequency sources for TimeNuts applications? https://www.sitime.com/products/stratum-3e-dcocxos/sit5721 The published specs seem quite remarkable for a device that is 5 x 7 x 9mm You have to request a data sheet,

Re: [time-nuts] SMPS or conventional?

From: ed breya To: mailto:time-nuts@lists.febo.com Subject: Re: [time-nuts] SMPS or conventional? "Regarding TEC life, ..." A really good reference to TECs, especially factors affecting lifetime is here - https://tetech.com/faqs/ John

[time-nuts] Quantum Time Dilation

It's been mentioned many times here that Time-Nuts are continually chasing down the more and more esoteric effects that make their clocks less than perfectly accurate. I wonder whether any of them have got their clocks to the state where corrections to quantum effects are now in their sights?

Re: [time-nuts] What do people use for measuring temperature?

Final input from me on this topic. The surprising, to everyone, result from the research paper referenced in the eevblog - https://www.eevblog.com/forum/metrology/long-term-stability-of-temperature-sensors/?action=dlattach;attach=412153 Was that the cheapest thermistor had a drift of less than

Re: [time-nuts] What do people use for measuring temperature?

Thanks for going easy on me Bob ... a case of more haste, less speed! I focussed on low long-term drift specs without realising I had turned up a voltage reference, sorry. However, I have found some YSI glass encased thermistors that have long-term drift specs of <10mK at 25C and 75C over a

Re: [time-nuts] What do people use for measuring temperature?

Would not a band-gap temperature sensor such as the LT6657 be better than a thermistor for precision, low drift applications? The above device has 30 ppm/√kHr long-term drift. That should hold a mk for a fair few years. John

Re: [time-nuts] Precise Pendulum

Interesting ... They quote - “At the other end of the scale, gravity dominates over very long distances, while quantum effects vanish entirely at these distances.” I thought quantum entanglement was valid over any distance - Einstein’s “spooky action at a distance”. Thus offering the

Re: [time-nuts] ThunderBolt question

Everyone ... I must admit to being amazed at the cavalier attitude to impedance matching. I dread to think what a state we would be in if the original telecoms networks were designed with such disregard. OK, my background is in the old telecoms - land-line stuff where we had a variety of

Re: [time-nuts] TICC / TimeLab fun

Chris I don't have any of that kit yet but it seems to me that the two units have locked to each other somehow, a bit like the question I raised a while ago about crystals locking to each other. Just a pure guess though. John ___ time-nuts mailing

Re: [time-nuts] Vaperware Parts and pulse stretching circuits

Date: Fri, 24 Apr 2020 23:19:24 + (UTC) Perry Sandeen said - "I believe It is a bit disingenuous to say: *It is a small-pitch device but not impossible to solder*. Really?? If you've dropped $750 to $1K for a stereo microscope and other specialized soldering equipment then you can

Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)

Bob kb8tq - Wed, 22 Apr 2020 07:46:34 -0400 Said - > A lot also depends on what sort of voltage / power the speaker is expecting. If it's a high impedance voice coil gizmo things aren't going to be as easy as with a piezo gizmo designed to work in a 1.3V battery powered greeting card. Where

Re: [time-nuts] OCXO and fluctuations after EFC adjustment

On Fri, 10 April 2020 14:31:53 -0700 Rick wrote: >At this time, I will give my usual speech about IMHO the fact that >since the invention of the DDS on a chip, EFC should no longer be used >for high performance oscillators. During my 50 years in the electronics industry I have always been

[time-nuts] Facebook, the master of Time

I just stumbled across this and wondered what people thought of it. https://www.popularmechanics.com/science/a31746495/facebook-time-synchronization-breakthrough/ John ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

Re: [time-nuts] Synchronisation of crystal oscillators

Since the answer to my original question of possible synchronisation was a reasonably resounding no, I started doing some design work and then got an off-post message from TVB suggesting the use of his neat PicDiv chips to divide all my crystals down to 1PPS. On ordering a batch he came up

[time-nuts] Synchronisation of crystal oscillators

My apologies if this is slightly off-topic, but it does concern crystal oscillators. I have a small collection of ancient crystals amassed over the past 50 years or so. Half a dozen are low frequency (3,600Hz, 10kHz, and 100kHz), long bar, crystals sealed into B7G vacuum tube bodies. I was

Re: [time-nuts] What is the BEST crystal?

Wow, that provoked an interesting discussion! Thanks for all the information and references to further information - it should keep me quiet for a while. Interestingly 50mm diameter was about the diameter of the crystals used by the British Post Office in the early days for generating a master

[time-nuts] What’s the BEST crystal?

Since the poor old SC cut crystal has been given such a kicking for its inconvenient placement of spurious responses, is there a better, or BEST crystal for putting in an oven and turning into a nice reference? John Cheers - John ___ time-nuts

[time-nuts] Oven Controlled Voltage Controlled SAW Oscillators

Do these devices have any use in the TimeNuts community? https://www.electronicsweekly.com/news/products/digital-integrated-circuits/iqd-launches-ocvcsos-2020-02/ They claim lower phase noise and noise floor and jitter. ___ time-nuts mailing list --

[time-nuts] PLL synthesizer information from TI

For those of you interested in exotic Phase-lock Loop synthesizers, I just received this information from TI - http://e2e.ti.com/blogs_/b/analogwire/archive/2020/02/10/why-component-integration-carries-weight-for-space-based-pll-synthesizers The web page includes a link to an application note

[time-nuts] Construction and shielding information

Gerard Thanks for the cornucopia of information, much appreciated. Cheers - John ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions

Re: [time-nuts] Power supply for time source concerns

Date: Mon, 23 Dec 2019 07:51:49 -0500 From: Charles Steinmetz mailto:csteinm...@yandex.com>> To: time-nuts@lists.febo.com Subject: Re: [time-nuts] Power supply for time source concerns Message-ID:

Re: [time-nuts] gpsdo 10MHz steering resolution

Bob This based in Germany, 50Hz mains, hence my thoughts. John ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.

Re: [time-nuts] gpsdo 10MHz steering resolution

I may be completely wrong here but if the span of that spectrum is 1kHz, then the spurs look like 100Hz mains hum frequency modulation of the 10MHz. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

[time-nuts] Bulk Acoustic Wave (BAW) technology

Just been sent information on this technology by TI. Is it of any use/interest to TimeNuts? https://training.ti.com/introducing-tis-bulk-acoustic-wave-baw-resonator-technology ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go

Re: [time-nuts] new WWVB BPSK dev board

Christmas sketching out some designs ... Thanks - John -Original Message- From: Poul-Henning Kamp [mailto:p...@phk.freebsd.dk] Sent: 4 December, 2018 11:03 PM To: Discussion of precise time and frequency measurement ; John Moran, Scawby Design Subject: Re: [time-nuts] new WWVB BPSK

Re: [time-nuts] new WWVB BPSK dev board

I'm a little puzzled as to why people keep calling 60kHz - 'RF'. Many Hi-Fi audio amplifiers go higher than that. As for an 'RF' front end, there are dozens of off-the-shelf op-amps that can amplify the signal from a tuned ferrite rod aerial sufficiently to then feed into a decent A-D and then