[time-nuts] Which Rubidium to Get?

[Magnus Danielson]

On 07/22/2010 01:58 PM, Bob Camp wrote:
> Hi
>
> Efratom and Datum are the same company. The LPRO is a staple on the e-place. The other common alternatives are Frequency Electronics, Symmetricom, and Tecelek (that's not the right spelling ...).

Tekelec/Temex/Spectratime
http://www.spectratime.com/achievements.php

Just looking at their Telecom Rubidium range, you will find that they 
provide second source for the LPRO, FEI 5650, FEI 5660 and PRS10.

Their Galileo passive hydrogen maser seems to be commercially available, 
there's even a request quote button for it. No doubt it will be a few 
dollars more than their rubidiums...

The Stanford Research PRS10 was not in your list.

> I would stick with the LPRO since it's the cheapest of the bunch. They all perform pretty well.
>
> What you will need for any of them:
>
> 1) The connector to interface with them - it's often something odd
> 2) A good heat sink - they generate a lot of heat
> 3) Regulated power - 19 volts is perfect for the LPRO.
>
> Wear out life is anywhere from 5 to 20 years depending on what you read. Best guess is that there's at least 5 years left on the LPRO's.
>
> Programable output is cute, but only if you need it. Most time nuts are after 10 MHz only.

If you are looking for a typical lab reference to go along with a GPS, 
then the LPRO is not a bad pick.

If you want to do more elaborate instrument like stuff like some of us, 
the programmable FEI is certainly an interesting solution. Both being 
obtainable for reasonable money on ebay.

>
> So many choices ....

Yes.

Start off with an LPRO or something. Read the manual carefully to 
understand the needs for cooling. If you create a servo-loop with a fan 
and heat-sink, you can allow higher temperature but lower power-consumption.

Cheers,
Magnus