[time-nuts] More HP5065 experiments

[Magnus Danielson]

Poul-Henning,

On 09/29/2015 10:01 PM, Poul-Henning Kamp wrote:
> --------
> In message <560AC40B.1040702 at rubidium.dyndns.org>, Magnus Danielson writes:
>
>>> If possible, I'd also check the spectrum of the lamp before and after
>>> the filter, depending on different lamp voltages, temperatures and
>>> filter temperatures. But that depends on having an optical spectrometer.
>>
>> The anti-pump line can be bothersome. This is where I like Corby's approach.
>
> I must admit that at least in the first iteration, I only plan to
> try to improve the electronics.
>
> Physics, including Corbys filter idea will be second iteration.
>
> My measurement of the lamp supply sensitivity was mainly intended
> to provide data on the required level of power supply stability.

I see that there is room for both approaches. The filter helps a lot, 
and clears the table with that aspect, so we can focus on intensity 
variations.

What I like about your approach is that you look at other stuff and try 
to see what is also un-attended to. For instance, the lamp oscillator is 
open-loop, so supply voltage and temperature effects will factor in 
undamped. Servo up the intensity seems to be the remedy there.

What about the C-field, can we servo up that by looking at the side-band 
Rabi/Ramsey pedistals? Yes, it should be there, but I haven't had the 
time to measure it. Doing that would require hacking into the 
synthesizer side and jump around on the 5,3 MHz signal much as you would 
do to the 12 MHz signal for Cesiums.

Servo or stabilize, it's interesting to see what stuff we can play 
around with on these large rubidiums, which seems to offer the 
possibility for improvements over what their original designs allowed for.

Cheers,
Magnus