Tektronix FG 504

P
roce
d ure
NO
ΤΕ
In t he following p r oce du r e, the test oscillosco p e
ve
r
tical i np ut requirements will be identified as
Differential
o r j ust
In
pu t .
Differential indicates a
system
providing differential o p eration with at least
1 m V l d ίν sensitivity . Wh en α test oscillosco pe is
mentio ne
d , use α 60 MHz (or greater) system wit h
5 m V to 5 V
/d
ίν sensitivity (200
MHz
for
ste p s 12 and
14) .
1 . Set +15 V
Supply
(
R 1605)
Set t h e digital voltmeter ra n ge to 20 V dc . Connect t h e
low level test lea d
to
t he
ground test p oi n t on the Al MAIN
board . Connect t he h ig h i npu t test lea d
to
t he +15 V
test
p oi n t on t h e Α 1 MAIN board . C heck for α r ea d i ng of +15 V
±30 m V . If outsi d e of tolera n ce, a d ju st R1605 (+15 V Ad j )
for correct readi ng .
NO ΤΕ
If R
1605 (ste p
1)
or R 1705 (ste p 2) settings requi r e
a dj ustme n t, t he entire ad j ustme n t procedure m u
st
be performed .
2 . Set -15 V S u pply ( R 1705)
M ove t he h ig h i np ut test lead to t he -15 V test p oint on
t he Α 1
MAIN boa
r
d . C
h
eck for α reading within ±10 m V of
t he ab sol u te value of t he +15 V su p ply readi n g i n ste
p
1 . If
readi ng is ou t of tolera n ce, a dj ust R 1705 (-15 VA dj) .
3 . C h ec kP owerSupply V oltages
M ove t h e h ig h i npu t
test lead to t h e test p oi n ts οη t h e Α 1
MAIN boar d a nd set t h
e voltmete r ra n ge switch as
necessary w h ile meas u ring t he followi ng su p p
lies for
liste d tolera nce limits :
Supply

Tolera n ce
+25 V

±0 .5 V
-25 V

+0 .5 V, -1 .5 V
+5 V

±0 .2 V
4 . C h ec k P ower Sup p ly R ip p le an d Noise
Set t h e Differential oscilloscope Trigger
to
L i n
e, V e r-
tical I np ut Cou p ling to ac, an d V ertical Se n sitivity as
re q uired
. Co nn ect α 1 Χ probe to eac h d ifferential i np ut .
Connect t he - (mi n
us) input p robe ti p to t h e F G 504
c h assis grou n
d . Con n ect t he + in p ut probe ti p to t he
ap pr o pr iate test p oi n
ts on
t h
e Α 1 MAIN board . C heck
ri p ple and noise accor d i ng to t h e following
table .
Calibratio nP rocedure- F G504 (S NΒ 040000 & UP)
A dj ustme n t Pr oce du re
S upp ly

Tole r ance
+15 V

Less t ha n 500 μ V ρ - ρ
-15 V

L
ess
t han 500 μ V ρ - ρ
+25 V

Less t han 5 mV ρ - ρ
-25 V

Less t h a n 5 mV ρ - ρ
+5 V

Less t h a n 100 m V ρ - ρ
Discon n ect t h e p r obes .
5 . Ad j ust T r ia n gle DC L evel ( R 360)
Set t he oscilloscope vertical i npu t co up li n g to dc,
volts/ d iv to 20 m V, variable volts/div as re q uired, time
base to 0 .5 ms/ d iv, trigger source to exter n al, and trigge r
mo de to auto . Co n nect α 10 Χ probe to t h e oscilloscope
vertical i np ut, t h
e p robe grou
n
d clip
toth
e
F
G 504 c
h
assis
ground and t h e probe tip to ΤΡ 1 on t he F G 504 Α 3 L OO P
board . Co n nect α 50 Ω coaxial cable from t he F G 504
T R IG O U T PU T to t he oscilloscope external trigger i n put
co
nn ector
.
Push t h e T R IGG ER FREE RUN
a
n
d tria
ngle
p ush butto ns i n . R elease t he H O L D/ RUN bu tton
to
RUN
(out) and set t he MUL TI PL I ER to 10' . A dju st t he os-
cilloscope for an externally trigge r ed 6- d ivisio n d is p lay .
Set t he oscillosco p e vertical i nput coupling to g r ound a nd
p ositio
n th
e trace
vertically
to
t h
e exact graticule center .
Set t he vertical i npu t cou p li ng to do a nd ad j ust R 360
(Triangle d o L evel) on t h e Α 3 L OO P boa rd for tria n gle
p ea ks e qu ally s p ace d a b ove a nd below graticule center .
Disco
nn
ect
t h
e 10
Χ p
robe .
6 .
A dj ust
Top
Dial W avefo r m Symmetry
(1152)
Co nn ect α 50
Ω
coaxial ca b le from t h e F G 504 O U T-
PU T terminal to α 50 Ω termi n atio n
co
nn
ected to
t h
e
oscillosco p e vertical i npu t . C han ge t he followi n g F G 504
co n trol setti ngs : Pu shth e square wave pus h button in a nd
set t h e FRE Q UEN CY Hz (STA R T) dial to 40 (40 kH z
square wave) . Set t he oscillosco
p
e
ve
r tical
for α 5
V
/div
display ; set time/ d iv, varia b le, a nd triggering (source to
Internal ; level as re q uire d ) so t he n egative-goi ng h alf-
cycle of t he square wave j
ust
fills t h
e graticule area
h orizo n tally . Switc h t he oscillosco
p
e trigger
slo p e
from +
to - w h ile ad j usti ng R52 (Top Dial Sym Cal) on t h e Α 3
L OO P board so t he h alves of t he squa r e wave are exactly
eq ual i
n
time (
R
52 only affects t he p ositive h alf) . Set t h e
oscilloscope trigger slope
to
+ .
7 . Ad j ust M inimum Dial W aveform Symmetry ( R
155)
C
h
ange t
h
e F G 504 FRE Q UEN CY Hz (STA R T) dial
setti ng
to
α p ositio n a pp roximately h alf
way b etween α .1
and 1
on
t he d ial and
set
t h
e
MUL
TI
PL I
ER to 10
°
. Ad j ust
t he oscillosco pe sweep s p ee d so t h e p ositive h alf of t h e
waveform cycle j ust fills t he graticule h orizo n tally . Switc h
t he oscilloscope trigger slo pe from + to -w h ile ad j usting
R 155 ( M in Dial Sym Cal)
on
t he Α 3 L
OO
P
board so
t h
e
h alves of t h e square wave are exactly eq ual i n time ( R 155
only affects t he n egative h alf of t he waveform) .