[time-nuts] Lamp for FRK Rubidium Needed

[Ed Palmer]

How did you make the measurement that showed a 0.8 Hz difference? What 
are the specs on your Racal reference?  When was it calibrated and 
against what standard?  That will tell you how much confidence to put in 
it's frequency.

As others have said, an FRK isn't a primary standard and should be 
calibrated against a primary standard.  However, 0.8 Hz is an error of 
8e-8.  I don't believe it's possible for a Rb standard to lock and be 
that far off.

 From your web site you seem to have quite an assortment of HF radios.  
Do any of them have enough resolution to do a quick check by using one 
of them as a transfer standard? Measure a known-accurate radio station 
frequency and then measure both the Racal and the FRK.

Ed

On 8/10/2014 4:01 AM, Peter wrote:
>
> Thanks to the help from members here I now have a locking FRK.
>
> My bulb looked pretty clear, and i couldnt find any deposits or "bits"
> inside, but decided to give it a good soaking at about 150 deg C using my
> hot air re-work gun for about 10 mins.
>
> I have checked it against my Racal ovened reference and found a discrepancy
> of about 0.8 Hz.
>
> Now the million dollar question...Can I be sure the FRK is good before I
> start to use it as my standard frequency?
>
> Is the FRK constructed in such a way that the frequency accuracy is assured,
> or do I need some way of verifying the FRK, or calibrating it.
>
> I dont want to trim my ovened reference to the rubidium, only to find the
> rubidium is not as accurate as I thought?
>
> Sorry if dumb questions, but just starting my quest for "time nut" status!!!
>
> Thanks
>
> Peter
> G0RSQ