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

[Mike]

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.
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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.
> _______________________________________________