Monday, April 25, 2011

Re: [HamBrewers] Mini Cesium clock module

 

Hi Yan,

These references don't need any input. They use the modulation of a cesium beam to generate a clock frequency. These chaps have made the Cesium lamp in 2mm cubic volume.. amazing!

Currently the affordable one is an used Rubedium reference which is about 120U$ range. This has good short term stability. One needs to calibrate it with a GPS based oscillator. I use a Thunderbolt unit with an external antenna and compare it with an old Rb unit and adjust it over a 10-20 minute period and that is good enough for me. I use the Rb output 10Mhz into my counters as external reference and take great pleasure in saying the accuracy is about 1 Hz in 1 GHz.. highly addictive hobby!

73 Raj vu2zap


As I understand this board needs to receive a radio signal in order to get the time.
Do you receive reliably this signal in India? What is its frequency?

Back in Europe few years ago I was used to have clocks synchronized with DCF77 signal on 77 KHz.
They are of no usage here for clock reference...

73,
Yan.
---
Yannick DEVOS - XV4Y/XV4TUJ
http://capheda.wordpress.com/ (Blog in french)
http://www.qsl.net/xv4tuj/ (web page in english)

Le 25 avr. 2011 à 15:01, Raj a écrit :

>
>
> This should keep our homebrewers from drifting!
>
> From the time-nuts group:
>
> http://tinyurl.com/CesiumMini
>
> or click here
>
> 73
> --
> Raj, vu2zap
> Bengaluru, South India.
>
>

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