Discussion:
how long dues this rubidium standard last for
(too old to reply)
Paul Bicknell
2018-05-09 21:45:37 UTC
Permalink
Hi all
as I am new to time nuts could someone please help with e following

questions

I have a Racal 9475 and a comment was it is a good entry level rubidium
That is not working yet
how long dues the rubidium standard last for and how much to replace ?

I assume rubidium & cesium's are left on 24/7
?

I think I would like a HP 5065
so how long dues this rubidium standard last for
?
and how much to replace
?


regarding the HP 5065 how much am I going to have to pay for one
?

I want to also do the Corby Dawson optical window modification
so How much is the new optical window
?

I realise the are a lot of questions but any answers would be welcome

Regards Paul B

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bob kb8tq
2018-05-10 02:21:21 UTC
Permalink
Hi

Rubidium standards are a “who knows” sort of thing in terms of life. Best guess
for the telecom Rb’s is 10 to 20 years. For a normal Cs standard with a high
performance tube, the life may be in the 6 or 7 year range ( I have replaced a
couple of those).

The HP 5065 is a rare beast. One sold on the list a little while back for ~$4K.

Bob
Post by Paul Bicknell
Hi all
as I am new to time nuts could someone please help with e following
questions
I have a Racal 9475 and a comment was it is a good entry level rubidium
That is not working yet
how long dues the rubidium standard last for and how much to replace ?
I assume rubidium & cesium's are left on 24/7
?
I think I would like a HP 5065
so how long dues this rubidium standard last for
?
and how much to replace
?
regarding the HP 5065 how much am I going to have to pay for one
?
I want to also do the Corby Dawson optical window modification
so How much is the new optical window
?
I realise the are a lot of questions but any answers would be welcome
Regards Paul B
_______________________________________________
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
William H. Fite
2018-05-08 22:49:14 UTC
Permalink
Bravo, bravo, bravo! On several occasions I have pointed out that there is
more to time-nuttery than striving to achieve an Allen deviation measured
in zeptoseconds. The silence in response is always deafening. If I want to
struggle with phase angles of billionths of a degree, I can go down to my
basement Chamber of Horrors and do that. But I can also sit in my den and
listen to all my mechanical clocks fighting over who strikes the hour
first. I revel in the cacophony of Westminster, St. Michaels, Whittington,
Rochester, Magdalen, Parsifal chimes all sounding at once, sorting them out
in my head, savoring the dissonances. I dote on the barometric drive of an
Atmos, the twirling of an el cheapo quartz filament clock, the squawking of
a cuckoo, and the constant clatter of a Congreve

I have a cesium clock, rubidium, GPS, etc. in the Chamber and I love
tinkering with them but I will never put a quartz watch on my wrist or an
"atomic" clock, even a 60 cycle synchronous clock on my wall.

Different strokes, I suppose.

Bill


Westminster Quarters, Rochester Quarters, Magdalen Chimes, Parisfal Chimes,
Guildford Chimes
In 'The Perfectionists' Simon Winchester Looks At History Of Precision
Engineering
https://www.npr.org/2018/05/07/608590826/in-the-
perfectionists-simon-wincheste
r-looks-at-history-of-precision-engineering
KELLY: You write about that in such a personal way in the book. You
include
the detail of your Sunday morning ritual, of walking room to room in this
old
farmhouse you live in and correcting all the clocks, you know, pushing one
hand forward a little bit and another hand back, and that you love the
inaccuracy of that, that they're all chiming totally out of sync by midway
through the next week.
WINCHESTER: Yes, a lovely description in Dorothy L. Sayers' book "Gaudy
Night" about the clocks in Oxford chiming midnight in friendly
disagreement.
Well, I like clocks having friendly disagreement. I loathe digital watches
with, I mean, the one I dare say you're looking at in the studio now, with
microsecond countdowns. Let's take it a bit easier. Let's be a bit fuzzy
in
our needs and desires and wishes.
-----------
I don't know if the book discusses time. If you aren't familiar with his
work, he's good.
--
These are my opinions. I hate spam.
_______________________________________________
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain

We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
c***@juno.com
2018-05-10 15:52:43 UTC
Permalink
Paul,

I agree with Bob, the small telecom ones to include the Efratom ones have
a lifetime that is just a guess at this point.

A brand new PRS10 with a warranty and the original owner repair discount
would be a good bet, they do however have lamp assy problems unless that
has been redesigned.

The HP5065A however has no significant failure modes, and I have worked
on and seen good performance out of 40 Year old units!

As discussed here before 5065A performance leaves the others "in the
dust".

The filter (either Edmund or Thor labs sell them) will run about
$170-$200 however you cannot guarantee a performance increase with every
5065A as there are other parameters that must be met.

The main problem is finding one that is affordable!

Due to it's excellent short term stability (<1.5X10-13th at 100 Sec) it's
in high demand and prices have been increasing as the available ones get
snapped up!

As Bob noted a last production serial number (prefix 2816A) recently went
for $4000.00

Mid vintage ones can run $2000.00

If you don't need the 5065A performance then just buy a telecom one
whenever your current one dies!

Cheers,

Corby

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Loading...