Re: [time-nuts] Anybody have suggestions for time related science fairprojects?

Well, how about the frequency drift between a pendulum, a tuning fork, and a crystal. Atomic standards could be added depending on availability. Bill Hawkins -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Thursday, May 10, 2018 11:56

Re: [time-nuts] Anybody have suggestions for time related science fairprojects?

Um, time dilation by altitude if you have access to a mile high change. Or subjective time dilation when a person is prevented from doing a task on time. Bill Hawkins -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Thursday, May 10,

[time-nuts] Anybody have suggestions for time related science fair projects?

A few months ago, I was a judge for the county level middle school science fair. (I'm not very good at what they wanted, but that's a different problem.) What sort of interesting time related experiments can a middle school geek do? Borrowing serious gear may not be off scale as long as a

Re: [time-nuts] nuts about position (cheap receiver)

> > > Results from the Z12 in L1/L2 mode were... iffy... then the receiver died. > The teqc tool from UNAVCO can help with diagnosing iffy data. Can you put your RINEX somewhere? With the antenna in an unobstructed area my Z12 routinely gives 1 cm-ish horizonal, few-cm 3D, using OPUS-S or

Re: [time-nuts] Ashtech Z12 question.

> Well, my Z12 stopped tracking sats yesterday. It passes all self-tests. > I then replaced the memory backup batteries... it fixed the bootup error > problem, but still won't track sats. > Rats. Is the antenna known to be good? Is the Z12 providing bias on the antenna cable? Did the Z12

[time-nuts] nuts about position (cheap receiver)

I have Lady Heather's RINEX writer working fairly well. Handles GPS and GLONASS (should also do Galileo when the M8T comes in from Germany... was "in stock" but it took them over a week to ship it). I just did a run on the Furuno GT-8736. It only outputs pseudoranges. A 2.5 hour run @ 1Hz

[time-nuts] Ashtech Z12 question.

Well, my Z12 stopped tracking sats yesterday. It passes all self-tests. I then replaced the memory backup batteries... it fixed the bootup error problem, but still won't track sats. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe,

Re: [time-nuts] Question about frequency counter testing

Hi > On May 10, 2018, at 1:44 PM, Oleg Skydan wrote: > > Bob, thanks for clarification! > > From: "Bob kb8tq" >> If you collect data over the entire second and average that down for a >> single point, then no, your ADEV will not be correct. > > That

Re: [time-nuts] Question about frequency counter testing

Bob, thanks for clarification! From: "Bob kb8tq" If you collect data over the entire second and average that down for a single point, then no, your ADEV will not be correct. That probably explains why I got so nice (and suspicious) plots :) There are a number of papers on

Re: [time-nuts] Question about frequency counter testing

Hi More or less: ADEV takes the *difference* between phase samples and then does a standard deviation on them. RMS of the phase samples makes a lot of sense and it was used back in the late 50’s / early 60’s. The gotcha turns out to be that it is an ill behaved measure. The more data you

Re: [time-nuts] Question about frequency counter testing

I'm a bit fuzzy, then, on the definition of ADEV. I was under the impression that one measured a series of "phase samples" at the desired spacing, then took the RMS value of that series, not just a single sample, as the ADEV value. Can anybody say which it is? The RMS approach seems to make

[time-nuts] how long dues this rubidium standard last for

Paul, I agree with Bob, the small telecom ones to include the Efratom ones have a lifetime that is just a guess at this point. A brand new PRS10 with a warranty and the original owner repair discount would be a good bet, they do however have lamp assy problems unless that has been redesigned.

Re: [time-nuts] Question about frequency counter testing

Hi If you collect data over the entire second and average that down for a single point, then no, your ADEV will not be correct. There are a number of papers on this. What ADEV wants to see is a single phase “sample” at one second spacing. This is also at the root of how you get 10 second ADEV.

Re: [time-nuts] HP 5372A

Hi Magnus...     Appreciate any help!   I participate in the ARRL Frequency Measuring Test, and I would like to automate the measuring process.   I have two frequencies, A and B...   A is a GPS locked HP 3336B set to 455,000.000 Hz   I use the 3336B instead of the 455,000Hz BFO signal from my GPS

Re: [time-nuts] Question about frequency counter testing

Hi I have got a pair of not so bad OCXOs (Morion GK85). I did some measurements, the results may be interested to others (sorry if not), so I decided to post them. I ran a set of 5minutes long counter runs (two OCXOs were measured against each other), each point is 1sec gate frequency

Re: [time-nuts] HP 5372A

Hi, What issues do you have? Cheers, Magnus On 05/08/2018 02:32 AM, Don Murray via time-nuts wrote: > Hello Time Nuts... > > >   > Who is the resident expert on the HP5372A? >   > I have some operational questions.  ;-) >   > email off list please.  w4wj at aol.com >   > TNX all... >   > 73 >