wwv receiver

[Jim Pennell]

Another approach that can work, depending on your location, is 60 KHz
WWVB.

There was an article in Ham Radio (Which I can not find at the moment)
where the fellow used a large loop antenna, several amplifier stages, and
then a ZERO crossing detector to remove the amplitude changes from the
signal.

He got a very solid 60 KHz square wave that was as accuate as WWVB gets,
subject to the minor variations of 60 KHz propagation which can be ignored
for most purposes.

While this was not a precise as a GPS system, it would serve nicely for a
cal reference somewhere around 1e-8 if I remember correctly.


Jim Pennell

 

[Tim Shoppa]

It is not necessary to be traceable to a "National Standard."

That depends on what sort of work your shop/lab does. For lots
of purposes, there are legal and technical requirements for traceability.
(And there are companies who depend on this requirement for their
income...)

Tim.

 

[Dbowey]

Tim posted:
<< [email protected] (Dbowey) wrote in message

It is not necessary to be traceable to a "National Standard."

That depends on what sort of work your shop/lab does. For lots of purposes,
there are legal and technical requirements for traceability.
(And there are companies who depend on this requirement for their income...)
Why does it depend....? Any clock traceable to a Stratum 1 (10 E-12) source is
equal to whatever NIST has.

Don

 

[Don]

Back in the 70s this was done with a looped antenna, tuned to 10 mhZ,
straight to a rf amp section tuned to 10 mhZ narrow bw, then to a dual PLL
to pick the signal, lock onto it, form an agc, and feed the vco ( very small
tuning range to the outside world. 10.0000000mhZ.

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