Tektronix DC508 User manual

TEKTFIONI)@
INSTFIUCTION IVIANUAL
Tektronix, lnc.
P.O. Box 500
Beaverton, Oregon 97077
070 2460{0
Serial Number
Fnsl P.inrinO MAF 1978
5
1 GHz OUNTER
c
c0a
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:. -,;' .. ' l
Copyrighl o 1978 by Tektronix. lnc. All rights reserved.
Contents ol this publicalion may nol be reproduced ln any
lorm withoul the permission ol Tektronix, Inc.
Products ol Teklronix. lnc. and ils subsidiaries are
covered by U.S. and loreign patenls and/or pending
palents.
TEKTRONIX, TEK, SCOPE-MOBILE, TELEOUIPMENT,
and @ are registered lrademarks ol Teklronix. lnc.
Printed in U.S.A. Specilication and price change
privileges are resen ed.
WARRANTY
This Teklronix producl is warranled againsl deleclive materialsand
wo*manship, under normal use, for a period o, one year ,rom dale
of initial shipmenl. Tektronix will repair or replace, al its option,
lhose producls determined to be delective within the warranly
period and relurned, treight prepaid, to a Teklronix Service Center.
There is no implied warianly lor lilness ot purpose.
Please direct all requests lor service or replacement parts to the
nearest Tektronir Service Center or Field Olrice; include the type or
pad number ol the producl and ils setial nu0ber.
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TABLE
OF CONTENTS
Page
.iiiSAFETY INFORMATION . .
Section 1 OPERATING INSTRUCTIONS
lnstru ment Description . .
Repackaging lnformation
Preparation forUse ....
Controls and Connectors
OPERATOR FAMILIARIZATION
Direct lnput
Prescale lnput
Frequency Measurements
Totalize Mode
Section2 SPECIFICATION
Performance Conditions
1
1
14
1-4
1-5
1-5
1-5
2-1
2-4
Electrical Characteristics. . . .
Environmental Characteristics
Physical Characteristics
Section 3 PERFORMANCE CHECK PBOCEDURE
lntroduction
Test Equipment Required .
Preliminary Procedure
Preliminary Control Settings
The following servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not perform
any servicing other than that contained in operating
instructions unless you are qualified to do so.
3-1
3-2
4-1
4-1
4--l
4-2
Seclion 4 ADJUSTMENT PROCEDURE
lntroduction
Services Available - -
Test Equipment Required
Preparation
Seciion 5 MAINTENANCE AND INTERFACING INFORMATION
Preventive Maintenance
Corrective Maintenance . .
Prescaler Fuse Replacement
Prescaler Removal
Prescaler Troubleshooting
5-1
5-l
5-1
5-1
5-'r
@
DC 508
wAnflrfG
FUNCTIONS AVAILABLE AT REAR CONNECTOH . . .
I
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DC 508
6-1
6-1
6-2
6-2
6-2
6-3
6-4
6-4
6-5
6-6
6-6
7-1
7-1
TABLE
OF CONTENTS (cont) '.-
Seclion 6 CIRCUIT DESCRIPTION
Resolution Multiplier
Page
Direct lnput .......6-1
Standard Time Base - . - . -
Prescaler.....
Optional Time Base
External Clock
Gate Generating Circuitry
Count Processing Circuitry . .. ...
Leading Zero Blanking
Display Timer
Power Supplies
Prescaler Un blank ing
Section 7 OPTIONS
OPTION 1
OPTION 7
Section 8
Section 9
Section l0
. . .7-1
lntroduction
lnstallation . . . .
Sweeping Mode Operation . .
Nonsweeping Mode Operation
Circu it Description
REPLACEABLE ELECTRICAL PARTS
DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS
BEPLACEABLE MECHANICAL PARTS
Exploded View
...........7-27-1
7-2
CHANGE INFORMATION
(@
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DC 508
SAFETY INFORMATION
The tollowing general safety inlormation applies to all
operators and service personnel. Specitic warnings
appear throughout the manual where they apply and
should be tollowed in each instance.
WARNING statements identily conditions or practices
which could result in personal injury or loss of life.
CAUTION statements identily conditions or practices
which could result in damage to the equipment or other
property.
The word DANGER on the equipment identif ies areas
of immediate hazard which could result in personal iniury
or loss ot life.
The following safety symbol appears on the equ ipment
Refer to the manual
Do Not Operale in an Explosive Atmosphere
To avoid explosion, do not operate th is instrument in an
area where flammable gases or fumes are present. Such
operation could cause an explosion.
Avoid Excessive Moislure
To prevent damage from arcing, circuit boards and
components must be dry belore applying power.
Do Nol Operale Without Covers
To avoid personal injury, do not operale the instrument
without the panels or covers installed. Do not perform any
servicing other than that described in the operating
instructions unless you are a qualitied serviceperson.
Do Nol Service Alone
Do not attempt internal service or adjustment unless
another person capable of rendering lirst aid and cardio-
pu lmonary resuscitation is present.
@t
A
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stt MAiluAl.
DC 508
Th6 DC 5Og 1 cH2 Counr€r
2460-1
ovtntLow MH. kll, GAlt
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Seclion 1-DC 508
OPERATING
INSTRUCTIONS
The 50 ohm prescale input has a vswr or 2.2:1 or less
and is protected by an easily replaced front-panel fuse
which opens at approximately 9 V rms. A wide-band
limiting amplifier with automatic gain control allows an
input sensitivity ol 20 mV rms over the frequency range ol
the prescaler input. lf the input signal falls below the
minimum level allowable for error free prescale counting,
the LED display is blanked and an input error light is lit.
Direct input signals can be applied to either a front-
panel bnc connector or to the rear interface connector.
The DC 508 is designed to operate in a TM soo-Series
Power module.
Save and re-use the package in which your instrument
was shipped. ll the original packaging is unlil lor use or
not available, repackage the inslrument as tollows:
The carton test strength for this instrument is 200
pounds per square inch.
Preparation For Use
fum the power module olf belore inserting the plug
in; otherwise, damage may occur to the plug-in
circuitty.
Check to see that the plaslic barriers on the inter-
connecting jack o, the selected power module compart-
ment match the culouts in the DC 508 circuit board edge
connector. Align the DC 508 chassis with the upper and
lower guides (see Fig. 1-1) oI the selected compartment.
Push the module in and press lirmly to seat the circuit
board in the interconnecting jack.
To remove the OC 508, pull on the release latch
(located in the lower left corner) until the interconnecting
iack disengages and the DC 508 slides out.
Conlrols and Conneclorc
See Fig. 1-2 for a description of lhe front panelcontrols
and connectors.
caurror{
@1-'t
lnstrumenl Desc.iplion
The DC 508 1 GHz Counter measures frequency lrom
10 Hz to 1 GHz. Frequencies from '10 Hz to'100 MHz are
measured using the direct input and lrom 75 MHz to
1 GHz using the prescaler input. The counter also
totalizes events from 0 to 999,999,999. Nine 7-segment
light emitting diodes (LED) provide a visual numerical
display which allows resolutions ol 1 kHz to 1 Hz (0.1 Hz
when using the direct input). The decimal point is
automatically positioned and leading zeros to the lelt of
the most signilicant digit or decimal point are blanked.
Digit overflow is indicated by a front panel LED.
Surround the instrument with polyethylene sheeting to
protect the finish ol the inStrument. Obtain a carton of
corrugated cardboard ol the correct carton strength
and having inside dimensions of no less than six inches
more than the instrument dimensions. Cushion the
instrument by tightly packing three inches of dunnage
or u rethane foam between carton and instrument on all
sides. Seal the carton with shipping tape or an in-
dustrial stapler.
Repackaging lnformalion
lf the Tektronix instrument is to be shipped to a
Teklronix Service Center for service or repair, attach a tag
showing owner (with address) and the name of an
individual at your firm that can be contacted. lnclude the
complete instrument serial number and a description of
the service required.
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Operating lnslructions-DC 508
Fig. 1-1. Plug-in module lnstsllatlon and removal.
POWER
MODULE
PLUG'IN
(l 2464 2
Top
Groove
Bottom
G.oove
Barrier
@1-2
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Operating lnstructions-DC 508
CONTROLS AND CONNECTORS
(13) OVERFLOW
lllumlnslcd when declm.l
countlng unlts ore tull, l.e.
rft6r !ll dlglls in the dlsptry
,ne nlne6.
(16) GATE
lllumlntlod dr.rlng tho
morturrmsnl Inleryal,
(3) STANDBY
Butlon oul remoreS power
lrom .ll cllcuitry ercepl the
optlon.l tkne bare osclllator
cl.cullry and crygtal helter.
(4) LOSS OF LOCK
lllumlnates when phsse lock-
ed loop lor RESOLN IIULT 13
unlocked.
(5) RESOLN MULT
Bullon ln multlplles frequen-
cy countCd, lrom'10 Hz lo 25
kllr, by 100 tor g,e.tcr
rerolullon. Butlon out counl3
lnput frgquency wllhout mul-
tlpllcatlon. 8u[on mu.t be
out lor ,requencles above 25
kH2, .nd when in TOTALIZE
mode.
(6) RESET
ilomentrry pushbutton
whlch rEs318 counter and lF
lumlnale3 all dlgilg tor seg-
menl check.
(7) AITEN
Bulton ln provlde. Xlo
rltcnuatlon lor lnpul slonal,
button oul Xl atlenustlon.
(10) |NPUT
lnpul connector for l0 H2 to
100 ilH: lignats (D|RECT
rNPUT).
(14) l{Hz
lllumlnated whoa counlet
unlL ar" ln meglhgrlz.
TI
[{PlJ]
OUT Of RAT6E
I
t PlrI
l5 100BMH.
50O V q115s 2!
STAIOEY
riss 0f
rot(
RtsoLt{
[.ULT
tti9!l
M!l?
lHr
l0tl!
(r2 |NPUT OUT OF RAt{cE
lllumlnated when amplltude
oa lrequency ia loo low lot
p,oper operatlon.
(r 1) |NPUT
lnpul conneclol lor 75 llH.
lo 1000 l, Hz slon.li
(PRESCALE INPUT}. -
AI
100N.
I- IXT
xr00 ^
xr .l-
s
^ 500
IMO
25gl
,L 300v
400v
II XTfiO N]T A
(9) s0 o -l Mo
Button ln select! lnpul lm-
pedance ot 50 n for DIRECT
INPUT conneclo., button oul
seleclr I lro-
0Ytf,fL0W lt, ttr GATI
@
Flg. 1-2. Fronl panel conllols 6nd connectoB.
2460 3
1-3
(ls) kHz
lllumhlted uhen counlet
unllE arc In kllohqdr.
(r) BESOLUTTON
Selectr counler re.olutlon ln
DIRECT or PRESCALE
mode. Also 3elcclt
TOTALIZE mode. RESOLN
UULT swltch must b€ ln lhe
Xl porltlon lor TOTALIZE
ope.atlon.
(2) DTSPIAY TrME
Selocls llme lrom end of one
meaaunement gate lo the
.t!rt ol the nert gale.
PBTSCATE DIRTCT
BISPI.AY TlMt -!>RtS0tUTl0lI
1Hr ToTAtl2t
l0llr
I tH.
BTSfI
^ xr()
lrl
hr
rust
lr16A
stE
(E) SOURCE
Butlon ln aelecl3 rear lnler-
lace conneclor lnpul, bullon
oul selecL tront prnel lnput.
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CAUT'OII
Operating lnstructions-DC 508
OPERATOR FAM ILIARIZATION
300 v
200 vMarlmum
vee 3oo viraxlmum
Vet 400 V
100 v
0v
2460-4
Flg. l-3. Marlmum lront psnel DInECT INPUT voltage!.
III\/
II
I\/
Nolse Hysleresls leyels
ol input Attenuated slghal
0v
Oulpul of
-
Schmlll lrigger
Etroneous counl Coarcct counl
2460 5
@
14
Fig. 1-4. An advantage in atlenurtlng input slgnal.
To avoid instrument damage, make cerlain the
voltages applied to the INPUT terminals do not
exceed the maximums lor low lrequency signals, as
stated on the front panel. See Fig. 1-3 lor an
explanation of terms and the Speciticalion section
fot higher lrequency limits.
Dlrect lnput
For input frequencies from 10 Hz to l00 l\ilHz use the
D IHECT INPUT. To use the Iront-panel input bnc connec-
tor, make certain the SOURCE pushbutlon is released.
Depress the SOUBCE pushbutton if the rear interlace
connector input is used. Select eilher the 50 O (pushbut-
ton depressed) or the l MO input impedance (butlon
released). Use lhe maximum practical attenuation to
improve triggering and reduce the possibility ot noise on
the input signal causing erroneous triggering. See Fig. 1-
4.
400 v
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Another way to couple signals into the DIRECT INPUT
is through a '10X probe. Use a probe capable of compen-
sating for the input capacitance ol the DC 508 (-20 pF).
Prescale lnpul
This input is terminated internally into 50 O. lt is also
fused to protect the input circuitry.
When using lhis input or the DIRECT INPUT ler-
minated into 50 O lor high frequency signals, use high
quality 50 O cable, components, attenuators, elc. to
prevent rellections or ringing caused by false counting. ll
the input amplitude or frequency at the PRESCALE INPUT
drops below usable levels, the INPUT OUT OF RANGE
light illuminates.
Operaling lnstructions-OC 508
When measuring lrequencies f rom '10 Hz to 25 kHz,
select the X1 or X100 resolution mu ltiplication factor. The
X100 position of the BESOLN MULT provides two ad-
ditional digits to the right of the decimal point for
additional resolution. ln either the X1 or X100 position oI
rhe RESOLN MULT, the LOSS OF LOCK light illuminates
when the multiplier is no longer locked to the incoming
signal. This may be caused by either the input signal
having insullicient amplitude, a frequency outside the
specilied range, or too much deviation if lrequency
modulated.
Totalize Mode
Place the RESOLUTION switch in the TOTALIZE
mode. Connect the events signal to be counted to the
INPUT conneclor, observing the same operating con-
ditions, with respect to the input as in the counter mode.
@1-5
Frequency Measurements
Set the RESOLUTION control to the desired resolution
for either the DIRECT or PRESCALE inputs. Note that a
light appears under either the MHz or kHz nomenclature
on the display. Make certain the STANDBY switch is
depressed. Adjust the DISPLAY TIME control as desired.
When this control is f ully clockwise, the display is held and
no further measurements are made. The lower the resolu-
tion, the fasler the count sampling rate as ind icated by the
GATE light. The counter is accurate even though the
OVERFLOW light is illuminated i, the digits to the left of
the most significant displayed digitare known. Forgreater
resolution, operate the counter with lhe mosl significant
digits dropped from the display and the OVERFLOW light
illuminated. To resel the counter, push the RESET button.
NOTE
Make certain the RESOLN MULT pushbutlon is out.
lgnore the loss oI lock light. The GATE light remains on
continuously. With no count, the least significant digit in
the display always displays zero. To reset the counter to
zero, press the RESET button.
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Section 2-DC 508
SPECIFICATION
Performance Condilions
The electrical characteristics are valid only if the
DC 508 has been calibrated at an ambient temperature
between +20'C and +30" C and is operating at an ambient
temperature between 0'C and +50'C, unless otherwise
noted.
Items listed in the Performance Requiremenls column
oI the Electrical Characteristics are verilied by completing
the Performance Check in the Service Section of this
manual. ltems listed in the Supplemental lnformation
column are not veritied in this manual. They are either
explanatory notes or performance characteristics tor
which no limits are specified.
Sensitivity (measured rrom a 50 O
source)
lmpedance
VSWB
Maximum Operating Input Voltage
lnput Protection Voltage
lnput OUT OF BANGE light
PRESCALE INPUT
Supplemenl,al lnlormalion
Prescale divides input frequency by 8
8 ms, 80 ms, 800 ms, and 8 s (1 kHz,
100 Hz, '10 Hz, and 1 Hz).
50 O ac coupled
<2.2:1
lnput fuse opens at -9 V rms
(+30 dBm).
Lights when input voltage is below
safe level for error-free counting.
lndicates input voltage is too low or
frequency is too high or too low.
Display is blanked after the gate time
when the sig nal has not met the minimum
input requirements.
Perlormance Requiremenls
<75 lMHz to at least 1 GHz
<20 mV rms (-21 dBm) from <75
N.4Hz to >1 GHz.
@2-1
Table 2-l
ELECTR ICAL CHARACTERISTICS
Characteristics I
Frequency Range
Gate Times (Resolution )
A two-pole high pass filter at about 75
MHz prevents erroneous counting if
frequency is too low.
Vpr('l5 V<2 V rms (+19 dBm) over the
specified operating frequency range.
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Specilication-DC 508
Table 2-l (cont)
Perrormance Requirements Characterislics
Frequency Bange
Gate Times (resolution)
External Sensitivity
External lmpedance
50r)
External Maximum Safe lnput Voltage
50f)
1 N/O, '1X Atten uation
1 MO, 10X Atten uation
Rear lnterface lnternal lnput
Sensitivity
lmpedance
Maximum SaIe lnput Voltage
Resolution Multiplier
Frequency Range
l\y' u ltip licatio n
Lock Time
Supplemental lnlormalion
1 ms, '10 ms, '100 ms, 1 s, '10 s, and
totalize (1 kHz, 100 Hz, 10 Hz, 1 Hz,
and .1 Hz).
lnput is ac coupled. On 50 Q range
term ination is dc connected.
Approximately 1 MQ in parallel with
approximately 25 pF.
Vel<400 V, Ve=p<300 V f rom dc to 0.75
l\,/'lHz.
Vpx(400 V, Vo=o(225-fvu" from 0.75
MHz lo 22 MHz.
Ver<400 V, Ve=e< 10 V above 22 MHz
DIRECT INPUT
Vp*(400 V, Ve=e<300 V lrom dc to 1
l'/ Hz.
Vpx(400 V, VFe<300 + fMH, from 1
MHz to 6 MHz.
Vpr<400 V, VD=,<100 V above 6 MHz
Pulse: V <4oo v, S<svzns
<125 mV rms from <10 Hz to >'100
l\il Hz.
50 Q a10o/o
@
<10 Hz to at least 100 MHz.
<15 mV rms f rom <.10 Hz to >100
t\,'tHz.
<'10 Hz to >25 kHz
<5s
2-2
x100.
1 t\,,to
50 r) r10%.
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Table 2-1 (cont)
Perlormance Requiremenls Supplemental lnlormalion
Accuracy
Frequency
Aging
Frequency
Temperatu re Stability
(0' C to +50'C)
Warm-up Time
Ag ing
At time of shipping
COUNTER ACCURACY
STANDARD INTERNAL TIME BASE
OPTION 1 INTEBNAL TIME BASE
,10 MHZ
<1 ppm/year
10 MHz with proportional oven
STANDBY switch allows power to
oven to remain on while power is
removed from remainder of
instrument.
<1 X 10 ' rms based on 60
consecutive 1 Second measure-
ments.
+2 parts in 10-3 or better
After 30 days of continuous
operation.
After 60 days of continuous
oPeration.
Short Term Stability
Adjustment Range
The overall DC 508 Counter accuracy
is:
Accuracy (o/o ol reading) : a llime
base accuracy + (l + total displayed
counts)l X 100.
Time base accuracy - + [calibration
accuracy + temperature stability +
(aging rate X time since calibration)
short term stabilityl.
Calibration accuracy - t
(calibrating standard accuracy +
ad justment resolution)
t5 ppm
t0.2 ppm after warmup
Within +0.2 ppm of linal lrequency in
less than 10 minutes when cold
started at 25'C ambient.
@2-3
Specilication-DC 508
Characlerislics
Temperatu re Stability
(0" C to +50'C)
1 X 'lO 3/day maximum.
4 X 1O-3/week maximum.
<1 ppm/year.
-\ Adjustment Resolution
Sulficient for 8 years of aging.
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Specilicalion-DC 508
Performance Requiremenls
Characleristics
Standard lnstrument
With Option 1
Characteristics
Temperature
Operating
Non-operating
Non-operating
A ltitu d e
Operating
Non-operating
Vibration
Operating and
Non-operating
Shock
Non-operating
Transportation
Supplemental lntormation
-15 W
Supplemental lnlormalion
+50'C to 95% relative humidity
+60'C to 95% relative humidity
Test lo MIL-STD-810C l/ethod 507.1
Procedure lV, modified as specitied in
i,4lL-T-288008 paragraph 4.5.5 .1 .1 .2.
Test to MIL-STD-810C l/ethod 500.1
Procedure I as specified in MIL-T-
288008 paragraph 4.5.5.2.
To 50,000 feet
With the instrument operating, the
vibration frequency is swept from 10
to 55 to 10 Hz. Vibrate'15 minules in
each oI the three major axes at 0.015"
total displacement. Hold 10 minutes
at any major resonance, or if none, at
55 Hz. Total time,75 minutes.
30 g's, 1/2 sine, 11 ms duration, 3
shocks in each direction along 3
major axes, for a total of 18 shocks
Qualified under National Safe Transit
Committee Test Procedure'1 A.
Category ll.
fable 2-2
ENVIRONMENTAL CHARACTERISTICS
@
Perlormance Requiremenls
0"C to +50'C
-55'C to +75'C
2-4
Table 2-1 (cont)
Humidity
Operating
POWER CONSUMPTION
Test to procedures of MIL-STD-810C
lvlethods 502.1 and 501.1 using
Procedure las specified in MIL-T-
288008 paragraph 4.5.5.1.3 and
4.5.5.1.4.
To 15.000 feet.
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Table 2-3
PHYSICAL CHARACTERISTICS
Specilicalion-DC 508
Characlerislics
lvlaximum Overall Dimensions
Height
width
Length
Front Panel
Fin ish
Net Weight
lnformation
4.969 inches (12.621 cm).
2.638 inches (6.701 cm).
12.088 inches (30.704 cm)
Anodized aluminum.
Standard lnstrument -2 lbs. 2 oz. (0.964 kg).
lnstrument with option 1 and 7 -2 lbs. 5 oz. (1.5 kg)
@2-5
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PERFORMANCE
CHECK PROCEDURE
Tesl Equipmenl Bequired
The lollowing test equipment, or equivalent, is
suggested to perform this procedure.
Section 3-DC 508
Suggested
Eul menl
TEKTBONIX SG 502.
SG 503 and SG 504 or
equ ivalent.
Hewlett-Packard 105A
Frequency Standard or
equ ivalent.
Tektronix Part Number
012-0482-00 or
equ ivalent.
Tektronix Part Number
012-0057-01 or
equivalent.
Stopwatch or
equivalent-
Tektronix TM series
power module as
required.
lnlroduclion
This procedure checks the Electrical Performance
Bequirements as listed under Specification in this manual.
Perform the adjustment procedure if the instrument fails
to meet the requirements of these checks. ln some cases,
recalibration may not correct the discrepancy; circuit
troubleshooting is then indicated. Also, use this
procedure to determine acceptability oI performance in an
incoming inspection lacility.
Table 3-1
Description
Sine-wave
generator
Precision 50 O
coaxial cable
Bnc male to GR
con neclor
Coaxial cable
Perlormance
Requiremenls
'10 Hz to 100 NilHz, 15 mV.75
Hz to 1 GHz, 20 mV.
lnternal time base temperature
stability.
SG 503 output connection
50r)
50r) Prescale th reshold adjust
Besolution multiplier lock time
All steps
3-1
Tektronix Part Number
017-0063-00 or
equivalent.
Frequency Stand-
ard, 1 MHz
Timing device
Power module
Used For
Frequency range and sensitivity,
10 Hz to 1 GHz: maximum
operating input voltage, 75 lvlHz
to 1 GHz; resolution multiplier
frequency range, 10 Hz to 25
kHz; resolution multiplier lock
time, 10 Hz to 25 kHz.
1 MHz with 1 + 1O-7 accuracy.
All steps.
@
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Preliminary Procedure
With the power module turned off, install the DC 508 in
the power module. Turn all equipment on. Depress the
STANDBY pushbutton. Allow at least 30 minutes warm up
time.
Preliminary Control Settings
Set controls as follows before each step
j. Check-that the display tracks the signal generator
over the entire frequency range.
k. Disconnect all cables
2. Check Maximum Operating lnput Voltages
a. Set the output voltage ,rom the sine-wave
generators, covering the frequency range from 75 MHz to
1 GHz, at 2 V rms.
b. Connect the output of the selected sine-wave
generator to the PBESCALE INPUT connector through a
50 O coaxial cable.
c. Set the RESOLUTION control to the l Hz
PRESCALE position.
d. Vary the output of the sine-wave generator from
75 MHz to 1 GHz.
e. Check-that the counter display tracks the lrequen-
cy ol the signal generator.
f. Disconnect all cables and return the controls to the
preliminary settings.
3. Check Resolution Multiplier Frequency Range
a. Connect a 10 Hz to 25 kHz sine-wave generator to
thE DIRECT INPUT,
b. Set the output amplitude of the sine-wave generator
tor an amplitude o, >'15 mV into 50 O.
c. Check-that the LOSS OF LOCK light is ofl for all
Irequencies from 10 Hz to 25 kHz.
4. Check Resolulion Mulliplicalion Faclor
a. Connectthe 10 Hzto25 k Hz sine-wave generato r to
the DIRECT INPUT.
ln
1 Hz DIRECT
ccw
Out
Out
Out
Out
ln
1. Check Frequency Range and Sensitivity
a. Connect the signaigenerator, capable of 75 MHzto
1 GHz, through a 50 O coaxial cable to the PRESCALE
INPUT.
e. Check-lhat the display tracks the signal generator
over the entire frequency range.
f. Set the output amplitude ot the sine-wave generator,
capable ol 10 Hz to 100 MHz, for 0.015 V rms into 50 Q.
h. Set the controls to the preliminary control settings
3-2 @
Perlormance Check Procedure-DC 508
d. Leave this setup Ior the next step.
b. Obtain a stable counter display of any frequency
between 10 Hz and 25 kHz.
STANDBY
RESOLUTION
DISPLAY TIME
BESOLN IV1ULT
RESET
ATTEN
SOURCE
50c)
b. Set the HESOLUTION to 1 Hz for the PRESCALE
INPUT.
c. Set the Amplilude of the signal generator to 0.02 V
rms into 50 O.
d. Vary the signal generator output frequency from
75 MHz to 1 GHz.
g. Connect the sine-wave generator to the DIRECT
INPUT connector through a 50 O coaxial cable.
i. Vary the signal generator output frequency from
10 Hz to 100 [.4H2.
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c. Check-that the most significant digit shilts two
places to the lelt and the count remains stable when the
BESOLN MULT button is depressed. Release the button.
5. Check Resolution Multiplier Lock Time
a. Connect the output of a sine-wave generator
capable ol frequencies from 10 Hz to 25 kHz to the
DIRECT INPUT.
b. Set the lrequency of the sine-wave at 25 kHzandthe
amplitude at >15 mV.
c. Obtain a stable counter display
eCheck-that the LOSS OF LOCK light goes out in
<5s
f. Disconnect all cables
6. Check Time Base Temperalure Stability
a. Connect the 1 MHz lrequency standard to the
DIRECT INPUT on the DC 508.
b. Check-that the least signif icant d ig it in the display
varies less than 5 digits (5 ppm) as the instrument is varied
from 0'C to 50"C ambient temperature.
c. Disconnect all cables
NOTE
The lollowing steps are applicable to Option 1 or
7 equipped instruments only.
7. Check
Stabilily
Pertormance Check Procedure-DC 508
Optional Time Base Temperalure
a. Connect the 1 MHz lrequency standard to the
DIFECT INPUT on the DC 508.
c. Leave this setup lor the nexl step
8. Check Oplional Time Base Warmup Time
a. Connect the 1 MHz troquency standard to the
DIRECT INPUT connector.
b. Set the DIRECT RESOLUTION control to .1 Hz
c. Alter complete warmup, note the displayed rrequen-
cy on the OC 508.
d. Remove the counler ,rom the power module and
allow the DC 508 to cool lor at l€ast two hours at 25'C
ambienl.
e. Place the counter in the power module at an ambient
temperature or 25"C and apply power to the module.
l. Check-that within '10 minutes after reinstalling the
counter in the power module the leasl significant digit is
within two counts of the previously noted reading.
g. Disconnect all cables
This completes the procedure
@3-3
d. Leave this setup for the next step.
d. Rapidly shift the lrequency of the generator to
10 Hz. Note that the LOSS OF LOCK light illuminates.
b. Check-that the least signiticant d ig it in the display
changes no more than two digits after warmup over the
ambient temperature range ot 0'C to 50'C.
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WARNING
THE FOLLOWING SERVICING INSTRUCTIONS ARE
FOR USE BY QUALIFIED PERSONNEL ONLY. TO
AVOID PERSONAL INJURY, DO NOT PERFORM ANY
SERVICING OTHER THAN THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE
QUALIFIED TO DO SO.
I .,/
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