Tektronix PG 508 User Manual

14 . A d j ust N ormal Complement B alance
C h ange t he osci Ι loscope swee psp eed to 0 .5 μ s . Set t he
O U TP U T ( V O L TS) H IG H and L O W level controls totheir 0
positio n and set t he N O RM /CO MPL E ME NT button out .
S h ort t he center termi n als of t h e NORM/COMPLEMENT
switc h as s h ow n in t
h
e
illustration . Increase t he vertical
gai n of t he oscillosco p e by α factor of 10 .
Νοω ad j ust R 910,
Ν
/C
ΒαΙ ,
for
eq ual h ig h and low level output voltages (no
signal) . R emove t he sh ort from t he switc h terminals .
15 . A dj ust Gai n
U si ng t he voltmeter co n nected to t he bottom center
termi n al of the Ν 0 R Μ /CO MPLEMEN T switc h and grou n d,
a dj ust t he O U
T
PU T"
( V
O
L
T'S)
L
O
W LEV E
L
control for
1 .33 V dc
.
Now co nn ect
t h
e voltmeter to
t h
e top
center pin
of t he N O RM /CO MPLEM E N T switc h a n d , wit h out movi n g
t he L O W L EV EL co n trol, set t he O U T PU T (volts) HIG H
LEV E L control for 3 .87 V dc . A dj ust R 885, Gain, fo r a pea k
to p eak outp ut am p litu d e of 10 V into 50 Ω .
16 . Ad j ust H ig hL evel Trac k ing
Wh ile o b serving t he wavefor m low level on t he os-
cillosco p e, vary t he H IG H LEV EL from 0 V am p litude to
maximum amplitu d e (10 V) and ad j ust R 915, H i Trk , for
min imum sh ift .
17 .
Ad j
ust L
ow
L evel T rac k ing
Observe t h e waveform h ig h level
on
t h e oscilloscope
and vary
t h
e
L
O W
L
E
V E L control from 0 V to m aximum
am p litude . Ad j ust R 920, L o Tr k , for minimum s h ift .
18 . Ad j ust Offset
Connect t h e voltmeter to t h e bottom center pi n of t he
N
O
RM
/CO
MPL
E
MEN T switc h . Connect t he negative lead
to grou
n
d .
Set t h
e
L
O
W LE V EL
co
n trol for α voltmeter
readi ng
of
2 .600 . Now a d j ust R 925, Offset, u n til t he
waveform low level is at 0 V on t he oscillosco pe .
19 . Ad j ust Output Impe d ance
Set t h e P erio d at ΕΧΤ TRIG O R MAN and t he
D UR ATIO N at ΕΧΤ DU R . M ake ce r tai n t h e " B RIG/GATE
LE
V
E
L
con trol is
t
u
rned
cloc
k wise enoug h
so
t he
Τ
'RIG'D/GATED
lig h t
is
lit .
Co
nnect t he O
U
T
PU
T
of
t he
P G 508 to t h e digital voltmeter through a coaxial cable and
b nc female to d ual b anana adapter . Ad ju st t he HIG H
LEV E L for α rea d ing of 10 .0 V on t h e voltmete r . Connect a
50 Ω termi n atio n between t he coaxial cable and ad apter .
A dj ust R 1020 for α rea d ing of 5 .0 V on t he voltmeter .
20 . Ad j ust Out p ut Amplifier
Connect t he OUTPUT terminal of t h eP G 508 t hrough α
coaxial cable a n d 10 Χ atte nuator to t he input of t he
sam p li ng oscillosco pe . Set t h e sam p li n g oscillosco pe
swee p sp eed at 20 ns p er d ivision . Set t he DURATION at
.1 μ s, PERIOD at .2 μ sa nd t he TRANSITION TIME at5 ns .
Obtain α free r unn
ing
u n d elayed output waveform
.
Ad j ust
t he O U TP U T ( V O L TS) H IG H LE V EL an d L O W L E VEL
co n trols for α 10 V pea k to p eak out p ut waveform centered
arou nd 0 V . Ad ju st R 1050, C1024a nd R 1024fort h efastest
risetime an d least aberratio n s on t h e traili n g tra n sitio na nd
cor n er of t he p ulse .
Internal A
d j ustme n t Procedure--PG
508
21 . A d j ust Control Error L ig h t
Co nnect t h e OU T PU T termi n al of t h eP G 508 t hrough α
coaxial cable and 50 oh m termi n atio n to t h e input of
t h
e
real time oscilloscope . Set t he oscillosco pe for α vertical
se n sitivity of 1 V wit h do coupling and for α 10 n s swee p
r ate . Set D UR ATIO N at 10 n s, PER IOD at 20 ns,
TRA N -
SI 1' ΙΟΝ TIME at 5 ns, TR AI L I N G a nd LE ADI
N
G co
n trols
fully ccw,
M
OD E UN
D L Y
b
u tto n i n and M OD ED EL AY
bu tto n out . Set all TR IGG ER I N G buttons to ou t p osition,
N
O
RM
/CO
MPLEMEN T b u tto n out and PRE SET/ V A R
button ou t . A dj ust t he O U TP U T ( V O L TS) HIG H LEV E
L
a nd L O W LE V EL co n trols for α d is p lay of 4 , 2 .5 d ivisions
an d --2 .5 divisions ce
n
tered aro
u
nd
0 V . A dj ust LE ADI N G
co
n
trol
cw
to
w here t he top of t he waveform is d ecreased
i n am
p
litude by 10 ο
/ ο (0 .5 d ivision) . A dju st C749 for α
flas h i n g indication of t he CO N TRO L ERR O R lig h t .
NO ΤΕ
If t h e CO N T R O L ERR O R
lig h
t does not
f las h , a d just
LE ADI NG cont
r ol
cw to
w he r e the to p of waveform is
d ecrease d by 5 ο/ο more (0 .25
division) ; t h enad j ust
C749 again
fo r α
flashing
in d icatio n . If t he lig h t still
cannot be ma d e to flas h with a d justment of C749,
conti
n
ue adjusting
t h e LE ADI N
G
control cw in
intervals
of α 5 ο/ο decr ease until a d justme n t of C749
results in α flas h i n g indication of t h e CO N T RO L
ERR O R lig h t (do not excee d α 50% ο dec r ease in
waveform am p litude) .
R ea dj ust C749 to α
point w h ere t h e CO N T R O L ERR O R
lig h t is j ust exti n guis h ed . R etur n LE ADI NG control to its
fully ccw p ositio n . A dju st TRAI L I N G con trol cw to w h ere
t h e bottom of t h e displayed waveform is decrease d i n
amplit ud e by 10 ο /ο (0 .5 d ivisio n ) . Ad j ustC744foraflashing
i n dicatio n of t he CO N TRO L ERR O R lig h t .
NO ΤΕ
If t h e CO N T RO L ERR OR lig h t d oesnot flas h , a d just
T R AIL I NG control cw to w he r e t h e bottom o f
waveform is d ecrease d by 5 ο/ο more (0 .25 division) ;
t h en a d just C744 again for a flashing indication . If
t h e lig h t still
cannot
be made
to flas h
with
a d just-
ment of C744, continue adjusting t he
T R AI
L
I N
G
cont r ol cw in
i n
tervals of α 5 ο/ο d
ecrease un til
a d justment of C744 results in α flas h i n g i nd ication of
t h
e CO
N T R
O
L ERR
O
R lig h t ( d o not excee d α 50 ο/ο
decrease in waveform am p litude) .
R ea dj ust C744 to α point w h ere t h e CO N TR O L ERR O R
lig h t is j ust extinguis h ed . R eturn TRAI L I NG control to its
fully ccw p ositio n .
Go back to ste ps 3,
7,
and 8 a
n
d p
erform t he a d-
j ustments
in t h
ese steps,
if necessary, for optimum
performa nce .
REV . Β A PR 1978

Tektronix PG 508 Specifications

General

Brand	Tektronix
Model	PG 508
Category	Pulse Generator
Language	English