[time-nuts] time-nuts Digest, Vol 102, Issue 90

Russ Ramirez russ.ramirez at gmail.com
Wed Jan 23 17:24:15 EST 2013


Yep, been there, done that. I'm a Ham and have several receivers. However,
that method falls a bit short for what I think I need and have decided to
look for something a bit better. What has been unknown to me is what result
I might get if I take a GPS solution such as this:
http://www.adafruit.com/products/746 and add the antenna and such, plus
design a circuit to discipline one of the OXCO's I have. This unit does
have a 1 pps output. I suspect more than resolution to X digits, there's
also the question of whether a (low end) unit such as this will reliably
stay locked. On the other hand, if I purchase something off-the-shelf that
is good to 10 digits, at least I know what I'm getting. Thanks for your
reply.

Russ
K0WFS

On Wed, Jan 23, 2013 at 4:02 PM, <time-nuts-request at febo.com> wrote:

> Message: 1
> Date: Wed, 23 Jan 2013 11:48:29 -0800
> From: Chris Albertson <albertson.chris at gmail.com>
> To: Discussion of precise time and frequency measurement
>         <time-nuts at febo.com>
> Subject: Re: [time-nuts] Least costly 10 MHz reference solution
> Message-ID:
>         <
> CABbxVHudh5Hp6xorwqH6PtH_S17VBGPtnr-FDtAO1zhR1rH-6g at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> >>.... My requirement/desire is to have a 10 MHz
> >> standard for my lab that I can trust to an accuracy of 7 decimal places
>
> At 10,000,000 Hz your required accuracy is 1Hz.  You can get to that
> level by "zero beating" to WWV.  This is very inexpensive, free if you
> already have a radio.  What you do is adjust the frequency of any
> local oscillator until the beat frequency with WWV is greater then one
> Hz.  You can either listen or use a scope
>
> Most people here are wanting 10 to 13 digits and that requires more
> work but 7 digitas is "way easy".  That said you might just as well
> get the GPS which gives about 13 digits over a longish measurement
> period.  But if you are looking for the lowest cost way to get to 1Hz
> the old methods will do that.
> In fact you can zero-beat any radio station that has a known
> frequency.  All comercial braodcast stations are good enough but WWV
> just happens to use a "round number" carrier freq.
>
>
>
>
> --
>
> Chris Albertson
> Redondo Beach, California
>


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