[time-nuts] HP5061B Square Wave Modulation Evaluation

Attached is a plot showing the measured floor of the sine wave loop in the 5061A/B and also in the 5065A, along with plot of an HP 5061B with a high performance tube. The tube is the limiting factor. As you can see the margin provided by the current design is substantial. Also if you look at

Re: [time-nuts] Three-cornered hat on timelab?

Hi There are a number of papers from the 70’s and 80’s digging into three corner hat data. The net result often would turn out to be “less than zero” noise on one of the DUT’s. Since that’s physically impossible the technique got a bit of “attention”. The Cliff Notes version of the results is

Re: [time-nuts] Three-cornered hat on timelab?

Hi John, I had a chance to think about this some more after I pressed the send key.  The ionospheric effects are certainly going to be different if the distance in time between tests is large.  And, of course, there is the fact that the KS has a pretty old receiver compared the Ublox I use, so

Re: [time-nuts] Three-cornered hat on timelab?

Longer runs would be better to the extent that they give you smaller error bars in your tau range of interest, certainly. But any effects that influence one of your runs but not the others will render the 3-cornered hat solution questionable, if not outright invalid. Only through many

[time-nuts] HP5061B Square Wave Modulation Evalukation

https://www.febo.com/pipermail/time-nuts/2017-April/thread.html We did some testing to evaluate the advantages of square wave modulation instead of sine waves for locking to the atomic resonance peak. We drove J1 on the A3 board with a 2.8 Volt peak to peak triangle at 20 cps from a signal

Re: [time-nuts] OCXO Soft-Start

Hi If your MCU has a POR that resets the internal oscillator that’s an unusual part. Most of them I’ve seen simply reset the CPU…..Once the 8 MHz crystal oscillator is running at 37 to 53 MHz (or KHz) it may or may not ever return to 8 MHz on it’s own. Yes, you need to get into some nutty

Re: [time-nuts] OCXO Soft-Start

I can't say I have run into that issue with a MCU as most 21st century ones have a decent POR and Brown out detect (which typically burns 10x more current than a 32k XO + RTC, and may get switched off in battery applications, and then problems can occur). What does seem to come up is stuff hanging

[time-nuts] Last notice for live online class, Phase Noise Fundamentals

For anyone interested in a fundamentals class on phase noise, I'm teaching an online class with live instruction (including video recordings in case you miss a class) titled "Phase Noise Fundamentals." https://www.jitterlabs.com/support/training/phasenoiseclass Register with the coupon code

Re: [time-nuts] Three-cornered hat on timelab?

Hi John, Thanks!  With lesser equipment, such as the 5370A, would longer runs be better?  I used a set of 1 hr runs and the result wasn't quite what I had expected.  However, it may be that I had mislabeled the files, and thus got the sources confused.  Of course, it may be that the ionospheric

Re: [time-nuts] OCXO Soft-Start

On 4/13/17 6:17 AM, Bob kb8tq wrote: Hi It’s a good bet that there is at least one regulator IC inside any modern OCXO. As you slowly ramp the input voltage on a regulator, various odd things may or may not happen. A 1 mv / s ramp on the outside can be “who knows what” at the oscillator level.

Re: [time-nuts] Mini-circuits ZFSC-8-1 a a reference distribution

Hi If the circulators are good to 10 MHz and you have eight of them to play with, then certainly they can be turned into isolators. Unless you have a really unique source of them, that kind of gets this out of the cheap seats. The “why” of isolation is very application dependent. Without

Re: [time-nuts] OCXO Soft-Start

Hi It’s a good bet that there is at least one regulator IC inside any modern OCXO. As you slowly ramp the input voltage on a regulator, various odd things may or may not happen. A 1 mv / s ramp on the outside can be “who knows what” at the oscillator level. That said, slow voltage ramps are a

Re: [time-nuts] noise sources Re: Re. DIY atomic "resonator"

Hi You likely would get more noise density out of the NE-2 than the incandescent bulb. The advantage of the incandescent is that you can estimate the temperature fairly accurately and thus come up with the noise by calculation. We did the build as part of a radio club meeting back in the

Re: [time-nuts] UltrAtomic® Clock

My LaCrosse UltrAtomic® clock arrived yesterday from Amazon. In my case, the clock wasn't assembled on a Monday or a Friday, so nothing rattled, and the packaging defeated the animals in shipping. The clock was stopped, of course, at exactly 12:00. I installed four C-cells (big spender!),

Re: [time-nuts] Mini-circuits ZFSC-8-1 a a reference distribution

I have circulators but not on the splitter. Since there are no mixers down stream, would reverse isolation be necessary in this application? > On Apr 12, 2017, at 7:39 PM, Mark Sims wrote: > > My UCT-2008 rubidium reference uses the same splitter. It is driven by a >

Re: [time-nuts] Three-cornered hat on timelab?

> It was mentioned that Timelab can do a three-cornered hat. I can't find it. > Is > this something that can only be done with multiple Timepods connected, or > is there an option that I'm missing? Or is there some other tool that needs > to be used? For the record, I want to create the

Re: [time-nuts] OCXO Soft-Start

On 4/12/17 7:14 PM, Richard (Rick) Karlquist wrote: 10.9 MHz is likely the B-mode of the SC cut. (It's a different mode, not a different overtone). This mode has a tempco of 20 ppm and is used to do thermometry. IMHO, there is NO excuse for the oscillator designer to design an oscillator that