[time-nuts] HP5065B !!!

[Bruce Griffiths]

That paper appeared to describe how a laser is used to replace the 
rubidium lamp more completely than later papers that achieved better 
results.
I should have also included links to later papers that better illustrate 
the performance that can be achieved.

Bruce

EWKehren at aol.com wrote:
> I never came to that conclusion. There is enough work out there with
> results. My comment was to that particular paper that did not measure up to the
> work Corby has been doing. Still trying to figure out the purpose of the
> posting.
> Bert Kehren
>
>
> In a message dated 4/29/2013 6:34:24 P.M. Eastern Daylight Time,
> bruce.griffiths at xtra.co.nz writes:
>
> Since  performance improves as the bandwidth of the "lamp" spectrum
> decreases its  not unreasonble to suggest that a suitable laser source
> may improve  performance further.
>
> The following paper (and theoretical  considerations) indicate that your
> conclusions regarding the potential  performance of a laser pumped
> rubidium standard are  incorrect.
>
> http://tf.boulder.nist.gov/general/pdf/1219.pdf
>
> The  addition of second harmonic traps tuned to the 2nd harmonic of the
> modulation frequency of the resonance interrogation signals should
> improve the performance  considerably.
>
>
> Bruce
>
> EWKehren at aol.com wrote:
>    
>>   I am still sitting here trying to figure out the purpose  of posting  the
>> article on laser diode pumping of the Rb. One look at the  data  and it is
>> clear that Corby’s work far surpasses the data  shown in the paper. All
>>      
> it does
>    
>> is distract from Corb’s  accomplishments. Lets be clear, Corby has opened
>> the door of H Maser  performance for those that have a HP 5065A. Not all
>>      
> work
>    
>> is  done  but a giant step has been accomplished, the challenge now is to
>>   continue  the work. In simple terms it gets down to keep the A/V slope
>>      
> from
>    
>> turning  upward. Work is going on off list to address some  of the issues
>>      
> and
>    
>> maybe some  one is willing to contribute. But  what the list at a whole
>>      
> can do
>    
>> is contribute  data as to HP  5065A performance. There are quite a few
>>      
> 5065A’s
>    
>> out there but   very little data besides HP spec. To better tackle the
>> flattening of  the curve,  aging, temperature sensitivity, barometric
>>      
> pressure
>    
>>   sensitivity and even  humidity sensitivity has to be understood. It  is
>> unrealistic to get past 1 E-13  unless this is understood and
>>      
> compensated for. Also
>    
>> some of these parameters  will vary from  unit to unit and some degree of
>> tailoring to a particular unit   has to be considered in the design. Some
>>      
> tests
>    
>> have to be done by  those members  that have access to a Maser.
>> Also Corby   found out that units with older A3 modules did not get the
>> performance  boost but  replacement of A3 did get the super performance.
>>      
> That
>    
>>   confirms my suspicion that  there is room for work on frequency
>>      
> generation. PRS
>    
>> 10 does a direct  frequency generation. Somehow  using the  step recovery
>> diode as a mixer obviously works but is  it optimum, or is there a
>>      
> better way
>    
>> to generate the resonator  frequency? What is key to get the best  signal
>>      
> and
>    
>> S/N  ratio?
>> When previously mentioning aging control, concern was   voiced as to
>>      
> getting
>    
>> in to the HP 5065A. Corby’s work gets to the hart  of the  unit, the RVFR,
>> but Corby has gone four for four.   Adding control will only move the two
>>      
> C
>    
>> field wires to the analog  board and using 30 mA from the unit. Unit can
>> easily  restored to  its original condition as far as frequency control is
>>   concerned.
>> Obviously the RVFR is the big differentiator in the   HP5065A and I know
>>      
> of
>    
>> no commercially available unit that even gets  close but  once the work is
>> complete a look at a FRK may be in  order, I doubt it will ever  be as
>>      
> good,
>    
>> but there is room for a  filter and the physics part is considerable
>>      
> larger
>    
>> than today’s  units.  Some  other units may be using a filter but the
>>      
> physics
>    
>> package is so small that  compromises had to be made and  the goal was
>>      
> more
>    
>> cost than ultimate performance.
>> It is up to  the list to turn this in to a Maser like  performance with
>>      
> out
>    
>>   mortgaging your home.
>> Bert Kehren
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