[time-nuts] Re: A hobby application of precise time or frequency

[Joe Theobald]

My first exposure to precision timekeeping was by an amateur astronomer who was observing occultations of stars and required a precision clock.  This was back in the mid-70’s.  He built a WWV receiver and worked with NIST to get estimates of propagation delays to get his best time estimate.
Joe Theobald
jltheobald at cox.net



> On Apr 12, 2025, at 5:24 AM, Mike via time-nuts <time-nuts at lists.febo.com> wrote:
> 
> Hello, Time-nutters-
> 
> A hobby of mine is downloading imagery from the
> several NOAA polar-orbit environmental satellites.
> These satellites are in a relatively low orbital
> altitude of just a few hundred miles. Their downlink
> frequency is just under 2 Ghz. Their orbital period
> is just under 95 minutes.  I track these birds with
> an elevation over azimuth 2 meter parabolic dish
> antenna which at that frequency has a half-power
> beamwidth of just under 2 degrees.  Tracking them
> requires a relatively accurate time clock. A time
> error of just a couple of seconds will result in
> loss of signal.  If you are interested I can send
> a photo of my home-brewed tracking mount.
> 
> Mike Baker  Micanopy, Florida (just a few miles south
> of Gainesville, Florida.
> *********************************
> 
> 
> 
> On 4/11/2025 6:46 AM, Erik Kaashoek via time-nuts wrote:
>> Maybe the subject line is a bit clickbait but this is a serious question.
>> Hobby VNA are used to measure impedance for antenna, amplifiers, filters, PCB's and cables. Many applications for a VNA outside the professional world.
>> Hobby spectrum analyzers are user for hunting RFI, measuring harmonics of active devices, assessing what part of the spectrum is still available for wireless devices, etc... Again many applications.
>> But for time and frequency measurement the situation seems to be different. What are hobby applications for accurate assessment of stability, time or frequency?
>> For radio amateurs that operate in the GHz bands the accurate assessment of the frequencies of their generators is such an application but what other applications do exist and what are their requirements regarding accuracy?
>> I'm purposely excluding the applications where the accuracy is the goal instead of some usage for accuracy.
>> Any input is welcome.
>> Erik.
>> _______________________________________________
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