HP 204C Service manual

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HEWLETT
PACKARD
WV&Q
OPERATINGAND SERVICEMANUAL
MODEL204C/204D
OSCILLATOR
INCLUDINGHZO-204C
Serial Numbers: 204C - 0989Al5156
204C-HZ0 - 0989A15016
204D - llOSA03676
IMPORTANT NOTICE
To help minimize the possibility of electrical fire or
shock hazards, do not expose this instrument to rain
cess moisture.
Manual Part No. 00204-90005
Microfiche Part No. 002Q4-90055
@Copyright Hewlett-Packard Company 1968
P.O. BOX 301, Loveland, Colorado 80537 U.SA
Printed: December 1976

COPYRIGHT AND DISCLAIMER NOTICE
Copyright - Agilent Technologies, Inc. Reproduced with the permission of Agilent
Technologies Inc. Agilent Technologies, Inc. makes no warranty of any kind with regard
to this material including, but not limited to, the implied warranties of merchantability
and fitness for a particular purpose. Agilent Technologies, Inc. is not liable for errors
contained herein or for incidental or consequential damages in connection with the
furnishing, performance, or use of this material or data.

MODEL 204C/2WJ
OSCILLA-IOR
Manual Part Number 00204-90005
P.&Is 3-5, Paragraph 3-36. mange 35 hours f0 22 hOU,S.
Pago 6-6, Paragraph 5.13, Step d. Change 100 m” to 10
K7”.
P.ge 6.11. Tablo 6”2. mange A2 par, number from
0020466539 to 01X204-66640. Change 9T21 ~hru 8724
to 1420.0243. O&w 00204.07601, Clip: Batterv.
Page 6.14. Table E-2. Add *a,, 1251.4933, connector.
female: and A2Pl. 12514938, FOII”CC~O,. male. Under
miscellaneour. delete 5040”0615 Bsttery Holder and add
1400-0689 Battery Clamp (4 eachl.
Page 6.7, Table E-1. Change part number of Battery
WOlih (Option 001 and 0021 from 5040-0615 10
,400.0950.
Page 6.9. gable &2. Change A, Cl.5 ro 0160-0114. C:Fnd
0.47 ,LF. Change AlC19 TO 0160-0309. C:Fxd 4.7 ELF.
Charqc AlCHl to 1902-0041. Did+: bkdn 5.11 V. De.
Ihe c23.
Paqc 6-15. fable E-2. Change shield, chassis from parr
number 00204-69511 to 00204-69514.
ptlgs 7w7.5. Fiewo 7.2. mange CR1 to 5.11 v. change
C19 to 4.7. and delete C23.
Page 6”4, fable 6-l. Change the tafai quanfiw of MPS
3030-0033 from 2 to 8. Delete: MP9, 3030.0007 from
Table6-1.
30 August 1978 Supplement A for 00204.90005

m
HEWLETT
PACKARD
SAFETYSUMMARY
The toUnwlnSpsnaral rafot~ precautions must houlwsrvad durlnp all phasssof opwatlon, rwiw, and rapnlr of thir
Innrument. failuru to cumply with these pracauUon#or with rpscfflc wornInS td8awhars in tldr manual vldatan
ufew rtandwdn uf deslpn,manuf#ture. and Mended useof the inrtrumnnt. tfnwlatt4%ekard Cumpnnyassunwsna
IiabilitV for the customer’s failura tu comply with these rquiramanta. Thin II II SafetV Class 1 instrument.
GROUNDTHEllYSTRUMENT
To minimize shock hazard, the instrument chassis and cabinet must be conycted to an elec-
ttical ground. The instrument is equipped with a three-conduclot ac power cable. The power
cable must either be plugged into an approved three-contact alactticel outlet ot used with a
three-contact to two-contact adapter with the grounding wire (green) firmly cdnnected to an
electrical ground (safety ground) at the power outlet. The power jack and mating plug of the
power cable meet International Electtotechnical Commission MCI safety standards.
Do MOTOPERATEIN AN EXpL0SiVf ATMOSPHERE
Do not operate the instrument in the presence of flammable gases ot fumes. Operation of any
electrical instrument in such an environment constitutes a definite safety hazard.
KEEPAWAYFROMLIVECIRCUITS
Operating personnel must not remove instrument covets. Component replacement and internal
adjustments must be made by qualified maintenance personnel. Do not replace components
with power cable connected. Under certain conditions, dangerous voltages may exist even with
the power cable removed. To avoid injuries, always disconnect power and discharge circuits
before touching them.
DONUT SERVICEORADJUSTALONE
Do not attempt internal satvice ot adjustment unless another person, capable of tendering first
aid and resuscitation, is present.
DONOTSUSSTlTUTEPARTSORMODIFYINSTRUMENT
Beceuse of the danger of introducing additional hazards, do not install substitute parts ot pat-
form any unauthorized modification to the instrument. Return the instrument to a Hewlett-
Packard Sales and Service Office for service and repair to ansuta that safety features are main-
tained,
QANQEROUSPROCEUUREWARNINQS
Warnings, such a8 the example below, precede potentially dangatoua procedures throughout
this manual. Instructions conteined in the warnings must be followed,
piGi-
Uqarous voltqa~. cap~blaof uurinS death, armpvnont In thl8 lnntrumsnt Uao I*.
ttumr orutlon whsn bandllag, tet+tlnS,and aaudap

SAFETYSYMBOLS
General Definitions of Safety Symbols Used On Equipment or In Manuals.
A
Instruction manu,al symbol: the product will be marked with this
symbol when it is necessary for lhe user to refer to the instruction
manual in order to protect against damage to the instrument.
t Indicates dangerous voltage (terminals fed from the interior by
voltage exceeding 1000 volts must be so marked).
0
Protective conductor terminal. For protection against electrical
+ OR & shock in case of a fault. Used with field wiring terminals to in-
dicate the terminal which must be conn@ed to ground before
operating equipment.
Low noise or noiseless, clean ground (earth) terminal. Used for a
@ ..-,
vgnal common, as well as providing protection against electrical
shock m case of a fault. A terminal marked with this symbol must
be connected to ground in the manner described in the installation
(operating) manual, and before operating the equipment.
Frame or chassis wrminal. A connection to the frame (chassis) of
/$7 OR 1 t,rcs.
the equtpment which normally includes all exposed metal strut-
r, Altcmating current (power line),
--- Direct current (power line).
=s Alternating or direct current (power line),
The WARNING sign denotes a hazard. It calls attention to a pro-
cedure, practice, condition or the like, which, if not correctly per-
formed or adhered to, could result in injury or death to personnel.
The CAUTION sign denotes a hazard. It calls attention to an
m operating procedure. practice, condition or the like, which,if not
correctly performed or adhered to. could result in damage to or
dest,ruct;on of part or all of the product.
NOTE: The NOTE sign denotes important information. It calls attention
to procedure, practice, condition or the like. which is essential to
highlight.

‘I%hle nf Contents Model 204C/U
--o-
I. GENERAI. INFORMATION, l-l
1.3. Specificatiorrs Rntl General Information. l-l
I -I 3. Acccs&ics Available .............
1-I 5. lnsw~mcnt and Manual Identification
I .I 7. Change Sheets. .................
1.19. Options Available ..............
1”5. Description 1.1
1-2
I-2
1-2
l-2
Section Page
II, INSTALLATION ..................... 2-I
2-1, Introduction .................... 2.1
2-3. Inspection ...................... 2-I
2-S. Yowcr Requirements ............... 2-I
2.7. Grwndinp Requirements ............ 2-l
2.9. lmtaliatio” .................... 2-l
2-I 1. I<wk/Bench Installation ........... 2-l
2.13. Repackaging fur Shipment .......... 2-l
III. OPERATING INSTRUCTIONS.
3-l. Inl~roduction
3.3. Instrumcrll Description.
3-5. Turn On Proccdurc
3-7. Operating Considerations
3-x. Floating ourpur
3.10 Synchronization.
3.13. Low Distortion.
3.15. Mu&l 204D Output
3.18. linll~cry Operation
Page
3-l
3.1
3-I
3-l
3-l
3-l
3-l
3-l
3.4
3.4
3.19. Rcchargcable Battery Operolion 3.4
3.25. Rccharecabic Nickel-Cadmium I3alwxics 34
TABLEOFCCINTENTS
PlOP Page
1-I. Intioduction. l-l
Section V (Cont’d)
s-9. Attenuator Accuracy
(Model 204D only)
S-10. Output Control Check
(Models 204C and HZ0 only).
5-I 1, Output C!ontrul Cheek
(M&l 204D unl~)
5.12. Mance Check
5.13. Sync Output Check.
5.14. Sync Input Cheek,
5.15. Prcqucncy Range Cheek.
S-16. Hum and Noise Check
S-17. Checks of Gelleral Operaling
Characteristics
5.18. Output Voltage and
Impedance Checks.
5.19, Sync Impcdancc Cheek
5.20. Cuvcr Rrmuvsl
5.25. Adjustment and Calihrarian
Procedure
5.26. Introduction
5.29, Power Supply.
5.3I. Bias Adjurtmcnt
5.33. AGC arid Fi’equency Adjustment.
5.34. High Frequency Adjustment.
5-35, Distortion Adjustment,
S-36. Fsctoiy SCIwtcd Cumpuncnls
S-38, Truublcshwliny Proccdurcs
5.39. F,“,l,. I’HIICI Yruccdurc
541, Detailed Cirwil Twuhlcshooling
545. Battery Replacement,
5”4
5.4
5-5
5.5
s-5
S-5
S-6
S-6
5-l
5-7
S-l
5-l
5.8
5.8
5-R
s-u
5-8
5.8
s-u
s-o
S-8
s-9
5-v
5-i)
3.32. Cycle-fife of Nickel.Cadmium Hatt,crics 3-5
3J8. Mercury Uattcry Operation. 3-5
Sccliun
I”. CIKCUIT DESCRIPTION
section
“I. REPLACEABLE PARTS
h-l, Intruduction.
6.4. Ordering Information
6-h. Nun-Listed Parts
Page
4.1
4-1. Inhodoction. 4-l
Bridge and Amplifier. 4-I
Peak Cumparatorand AGC. 4-I
4-2
4,2
4-3
Section
4-4, Block Diwarn Descrintion 4-l
I
4-I 3. 600 Ohm At~tcm~~tur.
4.16. Dctailcd Cixuit Description
4-24. I’w,cr Supply.
VII, CIRCUIT DIAGRAMS.
7-2. Introduction
7-3. Schematic Diagrams.
7.5. Cornponcnt, Location Diagrams
Seelion
VIII. BACKDATING.
,, . . .,
Page
I-1
7-l
l-1
l-1
Page
8-l
D-l. I”~,w.l”Cl,O”. X-l
8.4. Chance No, I for 204C Serial No. 808-O 1245
MAINTENANCt. .. ..........
5-1, Introductiozl. ...... ......
5.4. Perfurmance Checks. .......
5.6. Uiel Accuracy Check. ......... ..
5.7. Flatness Check, ............
S.8. Distortiw Cheek ...........
il
5-l
5.1
5-l
5-I
S-3
and-low: 2O4C-I-120 Serial No. 808.00845
and IDWCl U-1
8-5. Change No. 2 for 204C Serial No. 9 I K-02 I20
and lower; 204C-1120 Serial No. Y 1%OlY70
and lower: 2041) Serial No. 910.OOIYS
and low, 8.1

I
Model 204ClD Table of Contents
Scctiun VIll (:Cont’d) Page
N-6. Change No. 3 for 204C Serial No. 962-04140
and lower: 204GH20 Serial No. 951-03765
and lower; 204D Serial NO. 910-00225
and lUWFl 8.1
8-7. Change No. 4 ror 204C Serial No. 951.03990
and lower; 204CH20 Serial No. 962-04290
and lower: 204W Serial NO. 910.00225
and hwcr a.2
SE. Charm No. 5 for 204C Serial No. 968.04840
and-lower; 204C-HZ0 Serial No. 989.05115
amI lower: 204D Serial No. 987-00570
Section Vlll (Cont’d) Page
8.10. Change No. 7 fur 204C Serial No.
OY89r-205715 and Iowe~: 204D Serial NO.
0987AOO745 and lower 8.2
8.11. Change No. 8 for 204C Serial No.
0989A15155 and luwcr: 204GH20 Serial
No. 1105A03675 and lower 8.2
Model 204C/204D
Model 204Cj204D
Section VIII 8-l
Section Vlll 8-2
and lower 8-2 Model 204C/204D Scctiun VIII 8,3 I
8.9. Change No. 6 for 204C Serial No. 988.04840
and Iowcr; 204C-HZ0 Serial No. 989.05115
and luwcr; 204U Serial No. 987”00570 APPENDlCES
and lower a-2 A. Code List of Manufxturcrs
B. Sales and Service Officer I
LIST OF TABLES
Table
l-l, Specifications. ....................... l-l 54. Distortion Ch
1.2. General information ................... l-2 5.5. Factory Selected Componcnls (*). .......... 5-9
S-l, IRequired Test Equipment, ............... 5-O 6-l. Model 204C Replaceablc Parts
5.2. Dial Accuracy Chwk 5-t (Including HZO) .................... 6-2 ...................
5.3. Flatness Check ....................... 5”2 6.2. Model 204D Heplnceablc Parts. ............ 6.9 I
LIST OF ILLUSTRATIONS
Figure Page
3-1. Dcvcriptiun ol‘Controls,
,rlic.l,nrr and Cnnncctors 3.2
4-1. Model 204C Block Diagram 4-l
4.2. RC Network Chwacterisrics. 4-2
5.1. Thermal Cor~verter Cheek 5-2
5-2. Flntncss Check 5.2
5-3. I MHz Distortion Check. 5-3
Figure Pa@
5.4, 204D Attenuator Accuracy Check 5”4
5-5S-5. Balance Check
S-6. Sync Input Check S-6
5.7. Hum wd Noise Check s-7
6.1, Model 204C Exploded View 6.4
6-4. Model 204D Exploded View .6.12
iv

Model 204C/D
SECTION I
GENERAL INFORMATION
1-l. INTROlJlJCTION.
1-2. This section contains general information about the
-hp. Model 204C, the -hp. Model HZO-204C, and -hp. Model
204D Oscillators. Throughout this manual the instrument
will be referred to as the Model 204C/D when referring to
aI1 instruments, and the Model 204C, the Model H20.204C,
or the Model 204D when referring to one of the instru-
ments individually.
1.3. SPEClFlCATlONSANDGENERALINFORMATION.
1-4. Table 1-l lists the specifications for the Model
204C/D. Table 1-2 lists other useful information about the
instruments which is not specified.
l-5. DESCRIPTION.
1-6. The Model 204C/D is a wide range oscillator with a
sine wave output at frequencies from 5 Hz to 1.2 MHz The
output impedance is 600 ohms; and the maximum voltage
output is 5 V rms into open circuit, or 2.5 V rms into a 600
ohm load
I-7. The Model 2C4D is basically the same instrument as
the Model 204C, except the Model 204D has a step
attenuator added.
l-8. The Model 204C has a variable output with greater
than 40 dB attenuation, providing a minimum open circuit
output of less than SO mV rms. The Specification
H20-204C has greater than 20 dB attenuation. In addition,
the H20-204C is obtainable with the Opt. 02 Power supply
board only.
1.9. The Model 204D has greater than 10 dB variable
attenuation and 80 dB step attenuation in 10 dB steps,
providing a minimum open circuit output of less than 150
#V rms.
l-10. The output of the Model 204C/D may be isolated
from the cabinet and power line ground. This floating
output is balanced to better than 40 dB for frequencies up
to 20 kHz
1-11. The Model 204CjD may be synchronized with other
instruments. The SYNC connector on the front panel
provides a sync output signal greater than 100 mV rms over
the entire frequency range, OI accepts at external sync
signal from another sowx. This permits the Model 204C/D
to be synchronized with another signal sauce of the same
frequency 01 harmonic thereof.With a 5 V rms (z 7 V peak)
sync input signal, the external source may vary as much as
t/-5% in frequency and the Model 204C/D will remain
synchronized.
p/o TaMe 1-I. Specifications.
RANGES
Frequency: 5 Hz to 1.2 MHz in 6 overlapping ranges
PERFORMANCE
Dial Accuracy: t/-3% of frequency setting
Flatness (At maximum output into 600 ohms resistive
load I kHz reference):
5 100 300k 1.2M
W)
Hum and Noise: Less than 0.01% of output of 2.5 V rms
into a 100 kHz BW (10 Hz to 100 kHz) with the
204CiD tuned above 200 Hz.
Distortion at 2.5 V rms into 600 ohms, or 5.0 V mx
open wait:
OU’IT’UT CHARACTERISTICS
Output Control: 204C, greater than 40 dB range,
continuously adjustable. H20,204C, greater than 20
dB range continuously adjustable. 204D, greater than
10 dB continuously adjustable and 80 dB in IO dB
steps.