[time-nuts] Rb standard questions

Bob Camp lists at rtty.us
Mon Aug 12 20:07:03 EDT 2013


Hi

They made a change on the Efratom Rb's some time around 2005 that boosted the "normal" lamp voltage by about 3 volts. Without tracing out the circuit(s) there's no way know if they just bumped the bias voltage up or what they did. An "old" lamp voltage unit probably is ok to 4 volts or so. I'm not sure if the same is true of the newer "9 volt" units.

Bob

On Aug 12, 2013, at 6:52 PM, paul swed <paulswedb at gmail.com> wrote:

> From those voltages I speculate a long life. In the various RBs I have
> 2-3.5 V seems to be trouble.
> Every units a bit different. When the units gets very old you will see the
> lamp re-ignite. Generally this will be noticed as a significant random
> phase jump. If you have a lock light it will go out for 30-60 or so seconds
> until the system comes back on.
> When I get an old rb I attach a cheap digital pedometer with an opto
> coupler etc (Could be a FET or transistor just as easily) to the lock
> signal. It increments every time the system unlocks. Humorously I call it a
> loc-O-meter.
> Regards
> Paul
> WB8TSL
> 
> 
> On Mon, Aug 12, 2013 at 5:55 PM, Bob Camp <lists at rtty.us> wrote:
> 
>> Hi
>> 
>> On Aug 12, 2013, at 3:21 PM, Yuri Ostry <yuri at ostry.ru> wrote:
>> 
>>> Hello,
>>> 
>>> Tuesday, July 30, 2013, 3:03:57, Bob Camp wrote:
>>> 
>>>>> 3) what is the typical life of such a unit?
>>> 
>>> B> If it's run without a heat sink, about two years.
>>> 
>>> B> If it's power off on the shelf,  many decades.
>>> 
>>> There was another "aging factor" mentioned in some documents that
>>> circulate around the net. Helium can diffuse from atmosphere through
>>> glass walls ans change buffer gas composition inside the cells.
>> 
>> From what I have seen of "stored" cells - it's not a major issue.
>> 
>>> 
>>> Run well cooled, >> 10 years for 90% of the units
>>> 
>>> As I can see, my FRS-C still works well after approx 10 yrs on a cell
>>> site working 24/7 and 5 yrs sitting on the shelf. But lamp voltage
>>> that was recorded 5 yrs ago differs from the one that I measured
>>> when I put it back to work. It is lowered little bit.
>> 
>> The key question is - was it powered up in the cell site or simply sitting
>> powered down? A *lot* of the cell site Rb's were in "emergency backup"
>> applications (cell sites on trucks …). They sat around for 10 years, but
>> didn't run for very long at all.
>> 
>> Bob
>> 
>>> 
>>> 73!
>>> Yuri
>>> UA3ATQ/KI7XJ
>>> --
>>> Best regards,
>>> Yuri                          mailto:yuri at ostry.ru
>>> 
>>> 
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



More information about the time-nuts mailing list