[time-nuts] Re: What to expect from rubidium lock behavior?

[Bob kb8tq]

Hi

The Efratom “big” Rb’s are sort of an early version of the telco devices. 
Their design dates back well before the smaller units came out. There
also are very similar devices made by EG&G ( we wanted a part of that
market, back in the day ….). 

Bob

> On Dec 11, 2021, at 10:59 AM, Wilko Bulte <wkb at xs4all.nl> wrote:
> 
> hi Paul, Bob,
> 
> Is there a significant difference between these telco-surplus Rb and the more 'fancy' ones in this regard? 
> 
> I happen to own an Efratom MRK-HLN, which, I presume, is also more geared towards "always on". So, I wonder would the MRK be better or worse compared to a telco-surplus unit? Arguably a telco-surplus unit is also of the always-on variety or?
> 
> best,
> Wilko
> (newbie trying to get a feel for this)
> 
>> On 11 Dec 2021, at 16:27, paul swed <paulswedb at gmail.com> wrote:
>> 
>> Totally agree with Bob. Same experience.
>> 
>> 
>>> On Sat, Dec 11, 2021 at 8:12 AM Bob kb8tq <kb8tq at n1k.org> wrote:
>>> 
>>> Hi
>>> 
>>> Yes, that’s pretty normal operation for any of the telecom Rb’s. They
>>> also typically drift about 1x10^-9 over the first day of operation. It’s
>>> best to leave them running all the time. Second best is to turn them
>>> on a couple days before you need to use them.
>>> 
>>> Bob
>>> 
>>>>> On Dec 11, 2021, at 2:23 AM, Erik Kaashoek <erik at kaashoek.com> wrote:
>>>> 
>>>> My rubidium frequency standard (Accubeat AR60A) finally got its nice box
>>> with good cooling and some LED's showing the status.
>>>> While watching the unlock LED I noticed the AR60 say's it is locked,
>>> about 4 or 5 minutes after cold start, when the frequency error jumps below
>>> about 1e-8
>>>> It takes 2 or 3 more minutes of slow drift to become stable within
>>> 1e-10. Is this to be expected?
>>>> With this locking speed it is tempting to switch off the AR60A unless
>>> needed for some measurement. Would daily switching on/off have any impact
>>> on lifetime?
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