[time-nuts] Frequency reference
Richard W. Solomon
w1ksz at earthlink.net
Sun Apr 20 14:28:51 EDT 2008
You can never be absolutely sure of your frequency, no matter how
you measure it. That is the Holy Grail that the folks on this list
pursue but can never attain.
Since the GPSDO I built (actually two of them) uses the GPS satellite
system for frequency control, I feel it's as good as you can get in
this price range.
One experiment I tried to confirm that they actually worked was:
One GPSDO 10 MHz output was used as the external reference for an
EIP 535 Counter. The second GPSDO was used to lock up a 1 GHz PLO
brick set to 970.000 MHz. Reading the output of the 970 MHz brick
on the EIP counter produced a reading of 970 000 000. The last zero
did fluctuate +/- 1 digit randomly.
If I can resolve 1 Hz at 970 MHz, that's good enough for me and my
uses for it.
Can anyone do better for $100 ??
73, Dick, W1KSZ
>From: Attila Kinali <attila at kinali.ch>
>Sent: Apr 20, 2008 5:50 AM
>To: "Richard W. Solomon" <w1ksz at earthlink.net>, Discussion of precise time and frequency measurement <time-nuts at febo.com>
>Cc: Discussion of precise time and frequency measurement <time-nuts at febo.com>
>Subject: Re: [time-nuts] Frequency reference
>On Thu, 17 Apr 2008 08:47:48 -0700 (GMT-07:00)
>"Richard W. Solomon" <w1ksz at earthlink.net> wrote:
>> You can build a very good GPSDO for about $100 in parts.
>Stupid question, but if one builds his on frequency
>reference, how can you be sure it's acurate and precise?
>Or to but it in other words: how do you measure self build
> Attila Kinali
>The true CS students do not need to know how to program.
>They learn how to abstract the process of programming to
>the point of making programmers obsolete.
> -- Jabber in #holo
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