Re: [time-nuts] Helmholtz Resonator and other Maintained Oscillators

k8yumdoo...@gmail.com said: > The flex hose demonstration was interesting in that different regimes of > swinging speed resulted in oscillation in different modes. I wonder why. It depends on the speed of the air going through the tube. https://www.youtube.com/watch?v=4aJ36-TlPD4

Re: [time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

I saw that about the N atom trapped inside a C60 molecule, but also took note of the present cost of the material. I wonder how much is going to be required to make a good standard. Dana On Fri, Dec 8, 2017 at 11:40 AM, Tom McDermott wrote: > There's an interesting

Re: [time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

https://www.google.com/amp/s/spectrum.ieee.org/semiconductors/materials/to-build-the-worlds-smallest-atomic-clock-trap-a-nitrogen-atom-in-a-carbon-cage.amp.html > On Dec 8, 2017, at 10:38 AM, Ulrich Rohde via time-nuts > wrote: > > Impressive, Ulrich > > In a message

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi It might be, if it is then an upper turn in the 80C range is not all that crazy. Bob > On Dec 8, 2017, at 4:24 PM, Angus wrote: > > > That near the end of the temperature range the direction could also > give a good indication - assuming that there is only one

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi The early HP’s (anything before the 10811 would not have had SC’s in them. Depending on this or that they either had AT’s or BT’s. Bob > On Dec 8, 2017, at 4:06 PM, Jeremy Nichols wrote: > > My HP-103AR is low (the 1 MHz output reads 0.999 999 200 MHz) with the fine >

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

That near the end of the temperature range the direction could also give a good indication - assuming that there is only one problem... I think the 8600-3 is still an AT - the 8607 is SC. Angus. On Fri, 8 Dec 2017 15:40:08 -0500, you wrote: >Hi > >One basic question - Is the frequency high

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

My HP-103AR is low (the 1 MHz output reads 0.999 999 200 MHz) with the fine frequency adjust turned to maximum. I'm a rank amateur at this but the circuit diagram looks like a series-resonant (Pierce) oscillator. Looks like I need to replace one of the capacitors inside the oven with a smaller

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi One basic question - Is the frequency high or low? Assuming it’s an SC and on the lower turn, frequency low is possible with an off temperature oven. Frequency high is unlikely unless it’s *way* off temperature. How far off turn gives you how much delta F depends on the inflection

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

The 8601 that I have was about 2 deg C off turnover when I got it, but I can't remember what sort or frequency error that caused. The temperature coefficient was terrible with that error. Angus. On Fri, 8 Dec 2017 13:05:14 + (UTC), you wrote: > >Gentlemen, >We have an Oscilloquartz OCXO

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi The big deal with the BVA is that the blank is “isolated” from the mount by a set of slots in the blank edge. That lets them achieve single plane stress isolation. The intent is to reduce the impact of holder stress as part of aging. Moving the electrodes off of the blank is intended to

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi Assuming it’s a unit with a 60C upper end temperature and that the 80C is the oven temperature, that seems about right. The chart in the data sheet runs from 77C to 89 C. If it was a conventional / old style 5 MHz 5th overtone AT cut crystal the Q of the resonator would be up around 5

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Happy Holidays Magnus! What I was wondering was that the BVA is somewhat unique since other oscillators have metal directly deposited over the quartz resonator, where the BVA is capacitive coupled. I was wondering if that made the quartz age less if at all. Cheers; Thomas Knox

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Berts right about the 80C that seems high. But when I looked at the spec sheet no details. Regards Paul On Fri, Dec 8, 2017 at 1:35 PM, Bert Kehren via time-nuts < time-nuts@febo.com> wrote: > What about 80 C is that normal for an 8600? > Bert Kehren > > > In a message dated 12/8/2017 11:32:14

Re: [time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

Impressive, Ulrich    In a message dated 12/8/2017 12:41:23 PM Eastern Standard Time, tom.n...@gmail.com writes:   There's an interesting article in the December 2017 issue of IEEE Spectrum. Researchers at Oxford U. have fabricated an atomic reference based on a single nitrogen molecule inside

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

What about 80 C is that normal for an 8600? Bert Kehren In a message dated 12/8/2017 11:32:14 A.M. Eastern Standard Time, jn6...@gmail.com writes: My HP-103AR frequency standard has a similar problem. I have been advised to take it apart and replace one of the capacitors in order to bring

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi, There is sources of drift all over the place. The crystal has drift in it, the oscillator core has sources of drift. Already within a crystal there is a bunch of sources. Some can compensate each other. Improvements in production have reduced effects, but there is always something that

[time-nuts] IEEE Spectrum - Dec 2017 - article on chip-scale atomic frequency reference

There's an interesting article in the December 2017 issue of IEEE Spectrum. Researchers at Oxford U. have fabricated an atomic reference based on a single nitrogen molecule inside a 60-atom carbon sphere ("Fullerene"). The cage of carbon isolates the nitrogen from external electric fields, and

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

On 12/8/17 9:29 AM, Magnus Danielson wrote: Hi, The unloaded Q is above 3 million, which is another way to measure how unusual these are. If I had schematics I would be more inclined to do something. However, the value for me is not to have it as sharp 5 MHz source, but very low phase

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi, The unloaded Q is above 3 million, which is another way to measure how unusual these are. If I had schematics I would be more inclined to do something. Cheers, Magnus On 12/08/2017 05:58 PM, Bob kb8tq wrote: Hi One risk is that the oscillator may have drifted further than one can

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi All; Is the "Aging" generally related to the quartz, or other components? Happy-Merry; Thomas Knox From: time-nuts on behalf of Bob kb8tq Sent: Friday, December 8, 2017 9:58 AM To: Discussion of precise time

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi One risk is that the oscillator may have drifted further than one can easily adjust it by just changing a select cap. That seems silly when we are talking about < 1 ppm, but the 8600 is an unusual OCXO. The electrodes BVA is not your run of the mill crystal. The “air gap” (actually a gap

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi, Many include a EFC offset pot, but when you go out of range on that, as I have for one of mine, here is no real option execept pop the lid and potentially find a cap or change a cap. I have not seen any as I recall, but should maybe take a look. However, the value for me is not to have

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi These days there is really no reason at all to play with silver mica caps in an oscillator. A very normal ceramic NPO will do just as well. It also will be cheaper / easier to find. If you want to go exotic, go for glass or porcelain caps. It is pretty unlikely you will find them in a

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

I have also done this to older oscillators and it works. When you look at the caps in the unit, if you are lucky somehow you may be able to see what type they are. Yes silver mica but there are various qualities and tempco's. Try to match the quality if at all possible. Otherwise guess. Good luck

[time-nuts] TDEV or phase Dev for a GPSDO?

Has someone already done the work and plotted TDEV or phase Dev for a run of the mill GPSDO. Particularly for a GPSDO with a non-exotic oscillator.. Or, perhaps the USRP flavor? There's a fair number of Modified ADEV plots out there from time-nuts and others, so I can calculate it, but hey,

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

My HP-103AR frequency standard has a similar problem. I have been advised to take it apart and replace one of the capacitors in order to bring the frequency back into the range of adjustment. Sounds like you have the same problem. Jeremy On Fri, Dec 8, 2017 at 7:52 AM paul swed

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

I took a quick look at the spec sheet. It appears coarse adjustment is an option M and would actually be a pot. That speaks to another tuning diode for coarse? Or a pot on pot arrangement. That sounds ugly. Regards Paul WB8TSL On Fri, Dec 8, 2017 at 10:17 AM, Bob kb8tq wrote: >

Re: [time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Hi It is quite possible that nothing is actually broken and that the crystal has simply drifted outside the tuning range. It should be pretty easy to spot the coarse tuning device once the package is open. I would bet you will find a selected capacitor across the coarse tune or in series

Re: [time-nuts] Test WWV timecube against Cesium, Rubidium, MASER or other precision time (UT-1) metrology

On 12/7/17 1:29 PM, Bill Hawkins wrote: So yes, this could be interesting for a hobbyist, but it won't add anything to Science. A MASER is overkill. Heck, so are Rubidium and Caesium. A naked crystal will be rock solid compared to received WWV. OTOH, NTP has marvelous mathematical tricks to

[time-nuts] End-of-Range: Oscilloquartz OCXO 8600-3

Gentlemen, We have an Oscilloquartz OCXO 8600-3that cannot any longer be adjusted into 5,000,000 Hz.It is about 1 Hz out of 5 MHz and turning coarse/fineadjustment potentiometers cannot bring the frequencyinto its specification. Oven temperature is about + 80C accordingto the thermistor and

Re: [time-nuts] Helmholtz Resonator and other Maintained Oscillators

Use of a smaller opening would be the first strategy for getting higher Q. Making sure that the walls of the vessel were solid reflectors would be an important factor, too. I noted that several of his sustained oscillators were basically either relaxation or blocking oscillators, neither of which

Re: [time-nuts] Helmholtz Resonator and other Maintained Oscillators

What's the Q of a Helmholtz Resonator? What do I do to make a high(er) Q version? With a narrow band filter, it might make a neat demo/toy to pull an audio signal out of the noise. With 2 at different frequencies you could demonstrate FSK. -- These are my opinions. I hate spam.

Re: [time-nuts] Test WWV timecube against Cesium, Rubidium, MASER or other precision time (UT-1) metrology

martin.burni...@burnicki.net said: > Hm, this file is part of the standard NTP source code package available > here: http://support.ntp.org/bin/view/Main/SoftwareDownloads Argh. Good catch. Thanks. I knew that it came from the ntp package. I thought it was stand alone but it seems to use

Re: [time-nuts] Test WWV timecube against Cesium, Rubidium, MASER or other precision time (UT-1) metrology

Hal Murray wrote: > > kb...@n1k.org said: >> To get the accuracy into the 1 ms range on WWV, you would need a pretty good >> idea of the path length between you and WWV. > > Dave Mills has a program to compute delays. > > * By default it prints out a summer (F2 average virtual height 350 km)