Atomic Time - HP 5065A Manual

Mode! 50D5A
Th,;ory. and f,.t.,.mbnance
SECTION I
GENERAL
INFORMATION
1·1. INTRODUCTION
H!. Description
1-3, The Hew!ett .. Packard Model 5065A f1ubidiurn
Vapor Frequency Standard is a compact, se!f~contained
secondary frequency standard which uses an optically-
pumped Rubidium vapor cell as the reference clement
A 5 MHz oscillator is stabilized against a natural
atomic
msonanco~
the hyperfine transition of
Rubidium 87. This techn[que produces a long-term
stability of better than 1 " 10·-n per month with
excellent short-term stability which is conservatively
rated at less than 5 x 1 o····'i£ rms averaged over a one~
second period. Output frequencies are
6
MHz, 1 MHz.
and 100 l< Hz.
iw4. Frequency sottiog for any ottsot of the UTC time
ref-erence is
accompfi.shed by chanplng tho microwave
e.xcitation frequency and the magnetic- flo!d appHBfJ
to an Rtf' vapor celL Thumbwhoel swltch control
{ot a digito! frequency synthesizer} provides appr-oxi-
mate step adjustment of the microwave excitation fre-
quency ,,vith a range of 1000 parts in 10H-'_ !n adDWon,
the front-pane! MAONET!C FIELD control provides
tor exact atljustnH?nt of the
FH:/'~'
hyperfine trans!tion
'."lith
a
resdution ot 2 parts in 10v,
a. ,A
digihil
clocK, ()ption 001, provides a c1ock dis~
play
and a orF'J f)U!sc pet second 1 PFS
eiBctdcn! output
The c!ock puis<J rnay be
retnrdr~rJ
up to
1-~<E.•cond
in incn>
rn<rlnt~ a~; smal! Ets '!-rr:icrosccond and ;1s iarqe as 0.1
second fn
addih:;-n_
a
-:;epo.rilW cnntn:A provides conrin·
uou:s adju::A.rn :n\
ni
cic;ck--pi.;tsu
oewy
fron: 0- to i ·
rnicrosecond
b, E>tandby b£Htery, Option 002, provides a ·10-
min.ute rninimurn powBr sourcH (at 25';'C) in the ewmt
of external ac power faHum. A front-panel lamp
nash-as when ac power is interrupted and lights con-
tinuously during fast chaJQEL Charge rate is con-
trol!e<j by a
:)~position
front-pane! switch; FAST,
CHAnGE ·FLOAT, f1ESET.
\-?.
The ClHC:--un C:HECK
s;,-vitr_)'l
and rnelsr prc,vide
cont!nuc>.!s of outouts
2JJt1
other
:~:ignais
The CONT1NUGu::; OPEn.!\TlON !arnp o.n indi-
Cation ot correct mn:rati"on, The G MHL_ i MHz, aod
'lOO kHz
f)Utput
le~eb
are at inast
!
volt rrns when
properly 1err'r1inated with 50
ohm~;L
1·8, TERMINOLOGY
1~9, The definitions o1 thn following terms appiy to
the~e
terms as used throughout trJis manua!.
a. ATOMIC TIME. Time scale based on the
hyperfine resonance of Cesium. 133.
b. UNIVEHSAL Tlt,JIE (UT2). Time scale based
on the earth's rotation about its axis with cortection
for angular position nnd seasonal val'iations; pmceeds
at a rate slightly stowor than Atomic time,
c. UNIVERSAL T!ME (CQOHOINA 1'EO) (UTC). A
piecewlse unlform scale which approxirrwtes UT2 to
0,
1~second by
stnp adJustments in phase as announced
by the-
Bureau lnttfrna.tiona! de !'Heure in Paris,
rt HYf'ERfiNE RESONANOE OF RbM
Hyp<>r·
nne resonant 'f
reqnency ar\s1ng fr-om th-e difference
ln energy between
trlB
upper and lower ground states
o!Rb"-
e.
HVFR
(FiubkJiurn Vupor Frequency Refersnco}.
The assornbly wh;c!\ t1ouses tho Hbi 1 ' tmnp, fdter cell,
the RbM absorption ceH, and the !lBrmonic gnnerator/
mixer diode,
1·10, SPECIFICATIONS
!w1·1~
Ta!J!n 1··:3 ii::ts the technical spsciticarionH for
the Mode-! 50623/'
1-12 Table 1- \ !i::::.ts E'qu!prnent suppHed and Tat:;!e
1-2
!h::~ts
;;Jcc:nr:.c><Yk<:. 8-"):Jih:'lhtc for the Moor;J 5ntJ()A_
1--14. Hewlett-Pocknrd LIS-O-S a twtH,ection nir;o··dlgit
serial nmnber (OOOOAOOOOOJ mounted on thG rear~
panel to identify \his imdrument The first tour dlgits
aro the serial and the lasi ffve digits fefot to thH
specific mstrun:<SnL
ff
tht:- serial
prdix
on your
lnstru-
m0:nt differs hom
that
listed on the td1e page of thh
manuHi, d!h:r(·nu::;\ sx:st hf':hveen the rnanua! and
your instrurw:nt
L'.~W<3r ~:;criti
are
do<
umontod
in Section Vi! M~d
t:;gtli?.<'
~Ji!H'iD! prdiXfi&
are
covered
!)'Y' H ma_nuai tlhin'<.-18
she(;t
inc!uck:d
with the
n·JflrHwL
!t this sh<~ot
i;,-,
nw;sinq conL:=-;ct \h,,> nearest t·lewfott~
Packard Sai(')g a_nd St'HvH,:;B offico (iists am provided
8t tho rear of tf'lh nwnual;