[time-nuts] Interesting frequency standard project

Alexander Pummer alexpcs at ieee.org
Fri Jul 4 18:59:34 EDT 2014


for an AM station is strait forward at first use a narrow filter to make 
sure that you have just one station and feed the filter out put into a 
limiter the output of the limiter will be the carrier.
73
KJ6UHN Alex

On 7/4/2014 3:27 PM, Hal Murray wrote:
> paulswedb at gmail.com said:
>> The key to these systems is that the transmitters have very good references.
>> In the US at least we have no requirement for that level of stability on the
>> MW broadcasts. Though evidently some stations are quite good. I think I have
>> a list some place have to re-look.
> How stable are they?  Could they provide a good regional reference if
> somebody with a good setup would measure several stations and publish the
> results?  How often would you have to measure?
>
> How do you measure the frequency of an AM or FM station?  Wait for silence
> and process it like CW?
>
> Any suggestions for a receiver (or whatever) that would be appropriate for
> that sort of project?  I assume the main requirements are an external freq in
> and a serial/USB port to adjust the knobs.
>
> ----------
>
> Ages ago, I remember seeing a small booklet (20 pages?) from NBS describing
> their setup with HP that was using NBC's atomic clock for time distribution.
> HP's part was to run the west coast calibration to get the delay over phone
> lines from the east coast to the west coast.  Has anybody seen a copy of that
> booklet online?
>
>




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