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1. AS ds Fe ASI s 9 grad a 5 etd 8 sr O 5918 4 sr O x00 O EER Pla 135440 8954 x0 C 1 OX x t gd v Sr QO dea atta 28 il 421 sets id o 015 9t ite AD wag ASt Egt a E s D Du A 430 0 GAS 16 40 ASI git p x giya 21TH ag andi ASI wl 64 B 21nS LET AL 31341 Nairo y 0 d w du Ces ire Me ef va 0 T 275 Y E S TAS d EE E t 1 Stra W 3 ira amp df t t wx UOIYH3N39 Uu 401Vaydu0 Wang n IHx 0S I EU 31341 379Nv1u1 Co 0 wn si Wa 028 538005 i1N3B8n3 E UICE 31 3 9D Thurlby Thandar Instruments Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England Telephone 44 01480 412451 Fax 44 01480 450409 e mail sales tti test com web site www tti test com
2. VR33 VRS VR28 24 Circuit Diagram 25 at gua d ot sra O sota ag B st sa ctw sta noc us x i AD x 340 NQ aS 8 We1BEIQ 1n241 05501 Socr frena TL Uude LM et sra 13930 Sra sins curi E BZ 8 gins IX371NI MY ee nee at Sra O agi 9 ra ag A as s aa tt Sra O as 5 Sra sins cmi SMS I m NES mock oi vera Ono L d 29 E Sa teaa com AS v BlAS pee 433 puni p Y ETAS i ASI IND tz Ni 2 ua x UM r4O 9 B Z1AS masa iN v s E re ut Xe Ww ima uiva 022104 V7 UA 92 ira O SEHA venus pi w 8 ib 58 tra Osewa ianuis 907 417 2 555 30 00 A Ni _ 031114 10m AS re A PIN s OU QUE san E MA BAYES 1 88 tra cama mia g 3 nes re Hi 5 12 tra veld ga ira O is Bt ird ag Bi ird nivo 41 ina vase gt tra Onos z St tra O wo vt ira eaog 82d Er ira Ono ans OOS at tra O us tt tra Oos O fe Cais AG 6 irg Oz pos 8 ird O zx 4 ira Ogoor 9 ira gae 5 ird Views v tra O us ffl d il ll E rd Ou DIES t era 2 ra O x H gll AD terairg O 1304 ASt d eU gnan 4 deae a ivo ru Ost tre 032207 5584 deu 1 AST D agt zow 5518 ASI
3. 27230 0520 27254 0010 35555 2730 Description TRAN NPN 2N2219A TRAN NPN BC549C TRAN NPN 2N3904T TRAN FET BF245AT TRAN MOSFET N CHAN ZVN3306A IC CA3080E IC LM324N1 IC LM358N IC MC3403P IC TSH10IN IC TLO71CP IC TLO72CP IC LF351N IC CLC430A IC MC1496P IC V REG 7805 IC V REG 7905 IC V REG LM317 IC V REG LM337 IC V REG 431 IC CA3046 IC 74LS74 IC 4011B IC 4053B IC 74HCTOON IC 74HC4052 IC NE521N PCB MAIN PCB ASSY CONTROL 44912 0460 Part No 22225 0220 22226 0101 23105 2470 23202 0270 23202 1100 Description SWITCH PUSH PUSH SPPH11470B KEYSWITCH ALPS SKHHBW RES SM0805 4K70F W1 RES 27ROF W25 MF 50PPM RES 100RF W25 MF 50PPM PCB ASSY CONTROL continued Position Q21 Q3 5 13 16 18 19 26 Q6 Q7 8 Q25 IC8 IC2 3 10 41 C36 IC23 IC18 24 1C15 16 IC7 20 IC4 22 IC19 IC21 27 28 025 26 IC39 IC13 17 IC12 IC37 IC1 9 IC6 IC14 IC5 Position SW15 19 SW20 25 R242 247 R201 R215 21 Part No 23202 1150 23202 2100 23202 2220 23202 2470 23202 3100 23202 3300 23202 4100 23202 4200 23202 5100 23377 1220 23377 3100 23347 0140 23347 0350 23347 0360 23347 0530 23427 9209 23427 9205 23450 0036 23461 0020 23557 0505 23557 0658 23633 0002 23984 0017 25021 0901 25030 0905 25601 9007 25061 0200 26100 0220 27153 1040 27236 0530 27238 0000 27239 1070 27239 1510 27250 2110 27254 1008 28500 9008 35555 2740 CASE PARTS 22 Descr
4. 180KF W25 MF 50PPM RES 270KF W25 MF 50PPM RES 1MOOF W25 MF 50PPM RES 4M70F W25 MF 50PPM RES 10MOF W25 MF 50PPM RES 10R2F W60 MF 50PPM RES 41R2F W60 MF 50PPM RES 51ROF W60 MF 50PPM RES 600RF W60 MF 50PPM RES 10K0B W25 15PPM RES 10R0J W33 MF FUSIBLE NFR25 RES PS H 100R CF 10MM RES PS H 470R CF 10MM RES PS H 1K0 CF 10MM RES PS H 2K2 CF 10MM RES PS H 10K CF 10MM RES PS H 22K CF 10MM RES PS H 47K CF 10MM RES PS H 100R CERMET 10mm skel RES 680RJ 258 TEMPERATURE DEP PCB ASSY MAIN 44912 0450 continued Position R145 223 R57 105 109 113 R97 165 184 235 R104 R111 R22 R16 69 154 234 R15 185 R3 228 R7 9 R143 R55 141 R6 R117 169 R27 28 64 94 166 188 230 R225 R56 R80 224 R95 189 R20 R5 174 R134 R132 133 R135 137 R73 R236 237 R9 VR8 VR14 20 23 24 VR12 38 VR21 VR3 6 7 9 13 18 22 37 VR2 4 5 11 19 36 VR15 16 17 VR10 TDR1 19 Part No 23424 0443 23424 0459 23427 0268 23427 0331 23427 0385 23427 0593 23427 9205 23427 9236 23428 0100 23428 1100 23557 0647 23557 0664 23620 0236 23620 0245 23620 0246 23620 0252 23620 0256 23620 0266 23620 9007 23662 0110 23662 0203 23662 0205 23662 0240 23662 0300 23662 0310 23662 0330 25021 0901 25031 0020 25115 0907 25130 0911 25130 9202 25130 9206 25211 9302 25336 5590 25344 0500 Description CAP 10NZ 1KV CER D10 P5 CAP 4N7 250V AC CER STR LNG Y CAP 22PJ 100V CER NPO P2 5 CAP 1NOK 63V CER HI K P5T CAP 39PJ 100V CER NPO P
5. SWEEP IN e 15V SUMMING SYM AMP 7 LIN iH V DIAL VE OV SWEEP LOG CONVERTER OUT AND SWEEP GENERATOR AUX TTL CMOS DUTPUT DV FREQUENCY FTT DOUBLER FREO f COMPARATOR OV m AMPLITUDE p MODULATOR AMPL I TUDE OV 15V 15V DC DFFSET vA 15V OV 15V o 15 SV OV 5V o 12V 15V RE POWER SUPPLY CDH TRIANGLE DIODE GATE AMP n l Sz a CAP MULTIPLIER mum 12V Y NBI COMPARATOR V SQUARE SHAPER SINE CONVERTER C M P C MAIN DUTPUT DAC JC FREG COUNTER AND A TO D Functional Block Diagram 10 Functional Description The relationships between the major circuit elements are shown in the block diagram The summing amplifier sums the voltages from the dial the frequency lock DAC sweep input and the internal sweep circuit and its output controls the magnitude of the complimentary current source and current sink This current varies from approximately 4 3uA to 4 3mA for a 1000 1 frequency change 005 to 5 0 The symmetry control adjusts the ratio between the current source and current sink The diode gate steers current into and out of the range multiplier capacitor and is controlled by the comparator output When the comparator output is high the charge on the capacitor will rise linearly producing the positive going triangle slope When the comparator outp
6. modulator is inserted between the preamplifier and the output amplifier IC21 is a balanced modulator IC24 is a differential amplifier which amplifies the difference between the open collector outputs of IC21 The circuit around IC37 forms a 400Hz oscillator the output is passed through a Sallen and Key low pass filter IC20B IC20A buffers the signal on the modulation depth control VR33 and also sets the dc bias for IC21 Sweep Ramp Generator The rate control VR31 determines the magnitude of the current source IC7A and Q12 This current is steered into and out of C25 by the operational transconductance amplifier OTA IC8 The voltage on C25 is buffered by IC7B to drive the stop control VR35 and the window comparator IC10A and IC10B The thresholds of the window comparator determine the limits of the ramp which are OV and 4V Q13 and Q14 are level shifters to drive flip flop The output of IC 12A is level shifted by R74 and R57 and clamped by D5 and D4 to be symmetrical about OV When the input to IC8 is high the OTA sources current into C25 when the input is low the OTA sinks current from C25 This loop is very similar to a function generator If either the set start or set stop buttons are depressed the loop is closed around the ramp generator forcing the ramp to be held precisely at its lower or upper limit IC10D buffers the signal on VR21 to drive the main board directly or via the log converter Sweep Log Converter IC3D sums
7. the A D inputs RAO pin 5 RA1 pin 6 and RA3 pin 9 RAO input measures the amplitude voltage VA RA1 input measures the Frequency Dial voltage VF which is used to display low frequency measurements RA3 input measures the offset voltage VOFT IC31 is a DAC that outputs a correction voltage to IC3 C when frequency lock is selected This correction voltage is adjusted by IC30 to maintain frequency lock IC35 and IC38 are multiplexers that are used by IC30 to input the instrument status IC30 updates the display with the correct settings 13 Calibration Equipment Required Oscilloscope Distortion Meter 4 5 digit Multimeter Reciprocal counting Frequency Meter 14 Only the case lower need be removed to gain access to all adjustments Allow 1 hour warm up with the case lower in place before commencing For best results use the following procedure 1 Power Supply 15V 20mV VR23 15V 20mV VR24 12V 0 5V 12V 0 5V 5V 0 25V 5V 0 3V 5VA 20mV VR38 6V 0 5V Offset Nulling Select 5k range frequency vernier to 3 0 sweep OFF IC TP Adjust DVM Reading 4 2 VR6 40 22 3 VR7 40 16 6 VR13 40 Nulling of the triangle amplifier is achieved by shorting its input TP5 and adjusting VR14 to give lt 2mV on TP4 Preamplifier and Output Amplifier DC Offsets Ensure that the DC offset control is at its centre detent Release all three function buttons Amplitude con
8. 0PPM RES 10K7F W25 MF 50PPM RES 11KOF W25 MF 50PPM RES 12KOF W25 MF 50PPM RES 12K7F W25 MF 50PPM PCB ASSY MAIN 44912 0450 continued 18 Position R106 R229 R37 R155 156 R24 25 75 76 R114 R42 45 R26 29 77 R32 121 R30 83 R33 49 84 88 101 158 R103 R34 R82 R78 81 R39 40 89 122 126 R120 175 R52 R115 161 R17 59 74 87 159 171 172 176 177 178 181 183 186 187 227 238 R136 R50 54 150 R63 152 R21 231 R226 R157 R147 R153 233 R18 232 R1 8 11 13 14 23 60 61 66 68 70 72 79 85 86 93 96 98 107 142 146 164 168 170 173 207 239 R19 R2 62 138 139 140 R12 151 167 RAT Part No 23202 3130 23202 3150 23202 3220 23202 3226 23202 3249 23202 3270 23202 3300 23202 3330 23202 3360 23202 3390 23202 3430 23202 3470 23202 3510 23202 3560 23202 4100 23202 4110 23202 4180 23202 4270 23202 5100 23202 5470 23202 6100 23206 0102 23206 0412 23206 0510 23206 1600 23215 3100 23222 0100 23377 1100 23377 1470 23377 2100 23377 2220 23377 3100 23377 3220 23377 3470 23379 1100 23387 1680 Description RES 13KOF W25 50PPM RES 15KOF W25 MF 50PPM RES 22KOF W25 MF 50PPM RES 22K6F W25 MF 50PPM RES 24K9F W25 MF 50PPM RES 27KOF W25 MF 50PPM RES 30KOF W25 MF 50PPM RES 33KOF W25 MF 50PPM RES 36KOF W25 MF 50PPM RES 39KOF W25 50PPM RES 43KOF W25 MF 50PPM RES 47KOF W25 MF 50PPM RES 51KOF W25 MF 50PPM RES 56KOF W25 MF 50PPM RES 100KF W25 MF 50PPM RES 110KF W25 MF 50PPM RES
9. 2 5 CAP 82PG 100V CER NPO P2 5 CAP 47PJ 100V CER NPO P2 5 CAP 18PJ 100V CER NPO P2 5 CAP 10PG 100V CER NPO P2 5 CAP 100PG 100V CER NPO P2 5 CAP 10U 35V ELEC RE2 P2 CAP 1000U 35V ELEC RE2 P5 CAP 1NOK 100V P E P5 CAP 4N7K 63V P E P5 CAP 100NK 63V P E P5 CAP 2N2K 63V P E P5 CAP 1UOK 63V P E P5 CAP 680NK 63V P E P5 CAP 10NK 100V P E P5 CAP 100NK 63V P C P5 CAP 150PJ 100V P C FKC2 P5 CAP 330PK 100V P C FKC2 P5 CAP 1N50J 100V P C FKC2 P5 CAP 3N3J 100V P C P5 CAP 22N0J 100V P C P5 CAP 220NJ 100V P C P5 DIO 1N4148 B R DIO BAT81 DIO 1N4002 B R DIO ZEN 3V0 W4 DIO ZEN 9V1 W5 DIO ZEN 6V8 W5 RECTIFIER BRIDGE W02G TRAN PNP BC559C TRAN PNP 2N2905A PCB ASSY MAIN 44912 0450 continued 20 Position C55 130 C124 125 C17 32 112 113 121 C135 C109 C16 18 C11 C15 C3 23 26 27 28 88 89 C2 111 136 C53 54 60 66 94 95 117 137 138 C56 57 131 132 C68 C38 C1 4 10 12 14 21 22 29 31 34 36 37 41 52 67 90 91 96 98 101105 108 119 120 123 139 140 C40 C25 C118 C39 C35 C5 C7 C6 C19 20 C8 C9 D1 7 12 19 27 28 35 D8 11 36 39 D29 30 43 44 D31 32 D33 D22 BR1 2 Q1 2 4 9 10 11 12 17 20 Q22 Part No 25377 0700 25377 5490 25381 0404 25601 0103 25601 0400 27106 0505 27106 0506 27106 0513 27106 0518 27106 0548 27106 0604 27106 0606 27106 0608 27106 0641 27151 0110 27160 0009 27160 0014 27160 0200 27160 0210 27160 0900 27164 0503 27223 0740 27226 0110 27226 0530 27229 0000
10. 80 33331 4970 33331 4960 33536 3820 33536 3810 31336 0250 37113 2010 37113 0400 37151 0390 37151 0380 37113 0170 48591 0560 Description WASHER M4 SPRING WASHER M3 SPRING SOLDER TAG SHAKEPROOF 4BA SOLDER TAG SHAKEPROOF 6BA WASHER M4 ZPST WASHER M3 ZPST SCREW NO 4 X 3 8 PLASTT PNHDPZ NUT M4 ZPSTREAR PANEL NUT M3 ZPST FOOT MOULDED GREY SCREW M3 X 6 PNHDPZ ZPST SCREW M4 X 12 TAMPERPROOF SPACER Rnd 7 32 IDx1 4 L Nyl WASHER FIBRE M3 RES 549RF W25 MF 50PPM MAINS LD 2M ST IEC UK PLUG 5A MAINS LD 2M ST IEC EURO PLUG BNC SKT BKHD 50R STANDARD WASHER SHK PROOF POT 10KA OW20BU F11 X 15 REAR PANEL PRINTED OVERLAY FRONT PANEL FRONT PANEL CASE LOWER RFI SCREENED CASE UPPER RFI SCREENED HANDLE BENCH INST CASE KEYCAP BUTTON MID GREY ABS KNOB 12 5MM D SHAFT MID GREY KNOB 21MM D SHAFT MID GREY BUTTON SWITCHBANKS MID GREY INSTRUCTION BOOK Position REAR PANEL EARTH MAIN PCB CASE UPPER CONTROL PCB FRONT PANEL FRONT PANEL EARTH REAR PANEL EARTH FRONT PANEL EARTH REAR PANEL EARTH FEET FRONT PANEL EARTH MAIN PCB CASE EARTH REAR PANEL EARTH CONTROL PCB FRONT PANEL REAR PANEL EARTH MAIN PCB CASE UPPER MAIN PCB CASE UPPER CONTROL PCB FRONT PANEL OUTPUTS FOR UK FOR EUROPE 23 Component Layouts M v3 5 56 51 TGSSO MAIN PCB MW LA 35555 2730 i vRea vRe3 L caz tci
11. Complies with EN61010 1 Complies with EN50081 1 and EN50082 1 Safety This instrument is Safety Class according to IEC classification and has been designed to meet the requirements of EN61010 1 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use It is an Installation Category II instrument intended for operation from a normal single phase supply This instrument has been tested in accordance with EN61010 1 and has been supplied in a safe condition This instruction manual contains some information and warnings which have to be followed by the user to ensure safe operation and to retain the instrument in a safe condition This instrument has been designed for indoor use in a Pollution Degree 1 environment no pollution or only dry non conductive pollution in the temperature range 5 C to 40 C 20 80 RH non condensing It may occasionally be subjected to temperatures between 5 and 10 C without degradation of its safety Use of this instrument in a manner not specified by these instructions may impair the safety protection provided Do not operate the instrument outside its rated supply voltages or environmental range In particular excessive moisture may impair safety WARNING THIS INSTRUMENT MUST BE EARTHED Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous Intentional interruption is prohibited The protective action mus
12. IC25 26 FOR IC25 26 FB1 5 T1 PCB MNT SW26 SW1 13 FOR FS1 FS1 FS2 5 PJ2 TP1 6 PJ6 9 WAY PJ7 5 WAY PJ1 PJ5 LK2 R4 R92 R53 R31 102 112 144 R163 R118 R10 35 90 148 149 R116 162 R43 44 R48 58 65 R110 R91 R128 131 R38 41 46 119 179 180 R108 R36 17 PCB ASSY MAIN 44912 0450 continued Part No 23202 1340 23202 1402 23202 1470 23202 1510 23202 1620 23202 1680 23202 1681 23202 1715 23202 1820 23202 1910 23202 2100 23202 2110 23202 2120 23202 2137 23202 2143 23202 2150 23202 2160 23202 2180 23202 2200 23202 2220 23202 2249 23202 2300 23202 2402 23202 2430 23202 2510 23202 2560 23202 2665 23202 2680 23202 2750 23202 3100 23202 3107 23202 3110 23202 3120 23202 3127 Description RES 340RF W25 MF 50PPM RES 402RF W25 MF 50PPM RES 470RF W25 MF 50PPM RES 510RF W25 MF 50PPM RES 620RF W25 MF 50PPM RES 680RF W25 MF 50PPM RES 681RF W25 MF 50PPM RES 715RF W25 MF 50PPM RES 820RF W25 MF 50PPM RES 910RF W25 MF 50PPM RES 1K00F W25 MF 50PPM RES 1K10F W25 MF 50PPM RES 1K20F W25 MF 50PPM RES 1K37F W25 MF 50PPM RES 1K43F W25 MF 50PPM RES 1K50F W25 MF 50PPM RES 1K60F W25 MF 50PPM RES 1K80F W25 MF 50PPM RES 2K00F W25 MF 50PPM RES 2K20F W25 MF 50PPM RES 2K49F W25 MF 50PPM RES 3K00F W25 MF 50PPM RES 4K02F W25 MF 50PPM RES 4K30F W25 MF 50PPM RES 5K10F W25 MF 50PPM RES 5K60F W25 MF 50PPM RES 6K65F W25 MF 50PPM RES 6K80F W25 MF 50PPM RES 7K50F W25 MF 50PPM RES 10KOF W25 MF 5
13. TG550 5 MHz Precision Function Generator Service Manual Book Part Number 48591 0610 Issue 1 Specification Safety EMC Installation General Functional Description Circuit Descriptions Calibration Parts List Component Layouts Circuit Diagram Table of Contents 11 12 14 17 24 25 Specification Specifications apply at 18 28 after one hour warm up at maximum output into 500 FREQUENCY Frequency Range Vernier Range Frequency Display Frequency Locking WAVEFORMS 0 005Hz to 5MHz in 7 overlapping decade ranges with adjustment by coarse and fine verniers 1000 1 on each range Auto ranging reciprocal measurement giving 4 digit resolution down to 10Hz to 1Hz on the 5Hz range resolution is fixed at 0 01Hz below 10Hz 0 001Hz below 1Hz on the 5Hz range Accuracy is 1 digit to 2 1Hz to 0 21Hz Symmetry off or to 0 42Hz Symmetry on on the 5Hz range below this the accuracy is 196 of range full scale unspecified with Symmetry on With vernier setting between 1096 and 10096 of range maximum frequency can be locked to the crystal reference to maintain it at the displayed value 0 01 Waveform specifications apply for the top decade of each frequency range SINE Distortion Amplitude Flatness TRIANGLE Linearity SQUAREWAVE Rise and Fall Times Mark Space Ratio DC Range SYMMETRY Symmetry Range Less than 0 596 on 500Hz 5kHz and 50kHz
14. ak to peak to drive the main output socket The microcontroller measures and displays frequency directly down to 0 2Hz below this the microcontroller s A to D converter measures the voltage at the summing amplifier and displays the corresponding frequency Amplitude and offset are measured by the A to D converter too The sweep generator provides a triangle wave with variable amplitude and speed that is summed with the dial at the summing amplifier External Count In is amplified by a comparator and measured by the microcontroller The power supply converts the incoming AC line voltage to the DC rails required by the instrument 11 Circuit Descriptions Power Supply DC Regulation Diode bridge BR2 rectifies the full output of the transformer C56 and C57 are the reservoir capacitors which supply the 15V regulators Fine adjustment is provide by VR23 and VR24 The x 12V rails are derived from the 15V rails with D31 and D32 The 6V rail is derived from the 15V rail with D33 IC39 is a 2 5V reference IC41B generates 5VA fine adjusted by VR38 IC41C and D provide 12VA Diode bridge BR1 rectifies the lower output of the transformer C131 and C132 are the reservoir capacitors which supply the 5V regulators Waveform Generation Summing Amplifier and Current Sources The dial and sweep voltages are summed by IC36B the output range of the amplifier is approximately 4mV to 4V for a 1000 1 frequency change Q1 gives inc
15. al measurement giving 4 digit resolution down to 10Hz to 1Hz on the 5Hz range resolution is fixed at 0 01Hz below 10Hz 0 001Hz below 1Hz on the 5Hz range Accuracy is 1 digit to 2 1Hz to 0 21Hz Symmetry off or to 0 42Hz Symmetry on on the 5Hz range below this the accuracy is 196 of range full scale unspecified with Symmetry on Display shows peak to peak amplitude or rms value Display corrected for attenuator setting 3 digit resolution accuracy typically 5 of range full scale 3 digit resolution accuracy typically 2 setting 1 digit Display corrected for attenuator setting External Frequency Measurement Frequency Range Input Sensitivity Measurement Time Resolution Accuracy Timebase Accuracy GENERAL POWER REQUIREMENTS AC Input Voltage Power Consumption Operating Range Storage Range Environmental Size Weight Safety EMC 5Hz to 20MHz fully autoranging 50mVrms sinewave Selectable 0 55 or 5s 6 digits in 0 55 7 digits in 5s 1 digit timebase accuracy 10ppm initial error 5 ppm year ageing rate typically less than 0 5 ppm C 230V or 115V nominal 50 60HZz by internal adjustment operating range 14 of nominal Installation Category Il 25VA max 5 C to 40 C 20 to 80 RH 10 C to 65 C Indoor use at altitudes up to 2000m Pollution Degree 1 260 W x 88 H x 235 D mm 10 2 x 3 4 x 9 2 excluding handle and feet 1 9kg 4 21b
16. e gate IC6 drives the Aux Output with a TTL CMOS compatible signal Waveform Generation Waveform Shaping The sine shaper comprises a monolithic transistor array IC 17 which is driven by the triangle amplifier The circuit has two non linear stages A pair of emitter followers A and D round the peaks of the triangle the output of this stage is impressed across R103 and R108 in series and applied to the second stage This comprises a differential pair B and C driven almost into cut off and converts the clipped triangle into a sinewave VR10 adjusts the gain of this pair to bring them close to cut off minimising sinewave distortion VR11 adjusts the dc operating point of the sinewave converter to give symmetrical operation on both positive and negative halves of the waveform The squarewave shaper is a diode bridge D36 to D39 driven by a level shifter Q26 which steers current into and out of R91 and C32 This gives a clean waveform which is symmetrical about ground When squarewave is not selected SW10A gates the signal off at IC6B Preamplifier The waveform selected by IC14 passes to the preamplifier 1C18 The 1 8V pk to pk output is connected to the Amplitude control via the AM switch 12 Output Amplifier Q21 and Q22 are complementary emitter followers and buffer the output of IC19 The DC Offset control is buffered by IC23A and IC23C and applied via R120 and R175 Amplitude Modulator When the AM button is depressed the amplitude
17. iption RES 150RF W25 MF 50PPM RES 1K00F W25 MF 50PPM RES 2K20F W25 MF 50PPM RES 4K7OF W25 MF 50PPM RES 10KOF W25 MF 50PPM RES 30KOF W25 MF 50PPM RES 100KF W25 MF 50PPM RES 200KF W25 MF 50PPM RES 1MOOF W25 MF 50PPM RES PS H 220R CF 10MM RES PS H 10K CF 10MM POT 10K LIN VO12L PV25F B10K POT 500K LOG FLAT SHAFT 25MM POT 10K LIN DETENT FLAT SHAFT POT 1K 1K GANGED V PCB MOUNT CAP 33PJ 100V CER NPO P2 5 CAP 47PJ 100V CER NPO P2 5 CAP 47PK 500V 5MM DIA P5 CAP SM0805 100NZ 50V CER Y5V CAP 10U 16V ELEC RC2 P1 5 CAP 100U 25V ELEC RE2 P2 5 CAP 100NJ 250V P E UNCOAT P7 5 TRIMCAP 4 20P 5MM GREEN DIO 1N4148 B R DIO BA482 B R TRAN FET NJ J309 LED T1 ROUND 3MM RED LCD IC SM TLC5615CD 10 BIT DAC IC SM 74HC4053 IC SM 74HCTOO IC SM 74HC107 IC SM 74HC 151 IC SM PIC16C924 08L PLCC IC SM 75107 XTAL 8MHZ MICROPROCESSOR PCB CONTROL Position R200 R211 217 218 222 R203 R216 R204 205 206 240 241 R212 221 R214 219 R220 R213 VR28 VR34 VR27 32 33 35 VR31 VR26 VR30 C70 C71 C74 C72 78 86 115 142 144 146 C76 141 143 C75 C73 VC2 D42 47 D40 41 Q24 LED1 2 LCD1 IC31 IC34 IC33 IC29 35 38 IC30 IC32 XTL1 Part No 20038 9502 20038 9501 20037 0401 20037 0400 20030 0266 20030 0263 20065 0030 20210 0102 20210 0101 20662 0540 20234 0027 20236 0010 20661 0258 20612 0011 23202 1549 22491 0120 22491 0270 22588 0004 23348 0701 23347 0175 33331 49
18. on to maximum adjust VR17 for 10096 modulation Release all 3 function buttons increase the oscilloscope gain and adjust VR19 for minimum output of the 400Hz modulation source Adjust VR20 for OV 50mV output Turn AM off Meter Calibration Calibration of the frequency meter was covered in 6 above Display select to amplitude 5k range squarewave adjust the amplitude control to give 16V pk pk 8V pk pk into 50 2 then adjust VR28 on the control board for 1600 on the display Display select to offset release all 3 function buttons amplitude to minimum offset control at centre detent connect a multimeter to the main output adjust VR22 so that both meters read the same Offset control fully clockwise adjust VR21 so both meters read the same 1 Sweep Sweep to ON LIN stop control to maximum 5M range vernier to minimum 005 hold in set start and adjust VR2 for 4 3kHz to 4 8kHz Select LOG hold in set start and adjust VRA for 4 3kHz to 4 8kHz Select 500k range hold in set stop and adjust VR3 for 500kHz VR34A on the display board adjusts display contrast Power Consumption 230V 100mA 115V 200mA VR34 vce VR28 Control Board Calibration Points 15 LOXO VR20 pc Fa eq w VREE vRe1 VR17 VRE3 VRe4 5 VR9 VR10 VR7 Gr oi VR14 O 8 VRS VR36 VR1 VR13 VR4 VR37
19. ould only be carried out by skilled engineers Please note the following points before commencing work The tracks on the printed circuit board are very find and may lift if subjected to excessive heat Use only a miniature temperature controlled soldering iron and remove all solder on both sides of the joint with solder wick or suction before attempting to remove a components Many of the integrated circuits are CMOS devices and are should be taken when handling to avoid damage by static discharge Dismantling the instrument 1 2 3 Invert the instrument and remove the 4 screws next to the rubber feet Lift off the case lower ensuring the front and rear panels stay with the case upper Remove the 6 screws securing the main pcb to the case upper and lift the pcb free complete with front and rear panels To remove the control pcb from the front panel first pull off the small knobs and unplug the two flat cable assemblies Then desolder all other wire connections between main and control pcbs at the control board end lift the assembly clear and undo the 8 screws which hold the control board to the front panel the control board can then be removed To gain access to the microcontroller the LCD must be removed The rear panel can be removed by undoing the tamper proof safety earth connection Reassemble in the reverse order taking care to remake connections exactly as before particularly the safety earth wiring DAC
20. providing the same signal as the 50 Main Out but from 6000 The 509 and 6000 sockets are not independent Aux Out Output Characteristics Frequency symmetry and phase the same as main outputs Output Level 0 to 5V TTL CMOS logic levels capable of driving 2 standard TTL loads Sweep Out When internal sweep is selected the sweep signal is available as a 0 to 3V ramp from 6000 INPUTS Sweep In The SWEEP IN OUT socket is set to Sweep In when EXT SWEEP is selected Input Impedance 10kQ Input Sensitivity 0 to 3V for 1000 1 sweep A Maximum Allowable Input Voltage t 10V Sweep Linearity Better than 1 Maximum Slew Rate of Sweep Voltage 0 1V us AM In The AM COUNT IN socket is set to AM input when EXT AM is selected Input Impedance 40kQ Input Sensitivity Approximately 2V peak peak for 50 modulation A Maximum Allowable 10V Input Voltage Count In The AM COUNT IN socket is set to external frequency measurement when EXT COUNT is selected Input Impedance Input Sensitivity A Maximum Allowable Input Voltage DISPLAY FUNCTIONS 1MO 25pF 50mVrms sinewave 50Vdc 50Vrms to 400Hz with respect to ground reducing to 1Vrms above 1MHz The LCD shows generator frequency simultaneously with output amplitude offset together with various status annunciators Alternatively it is the external frequency measurement display Internal Measurement Accuracy Frequency Amplitude DC Offset Auto ranging reciproc
21. r and lift off the case lower 3 Remove the 6 screws securing the main pcb to the case upper and lift the pcb free complete with front and rear panels 4 Change the appropriate zero ohm links beside the transformer on the pcb Link LK2 only for 230V operation Link LK1 and LK3 only for 115V operation 5 Refit the pcb to the case upper ensuring all connections especially safety earth are remade as before and refit the case lower 6 To comply with safety standard requirements the operating voltage marked on the rear panel must be changed to clearly show the new voltage setting 7 Change the fuse to suit the new operating voltage see below Fuse The correct time lag fuse must be fitted for the selected operating voltage For 230V operation use 125mA T 250V HBC For 115V operation use 250mA T 250V HBC Make sure that only fuses with the required rated current and of the specified type are used for replacement The use of makeshift fuses and the short circuiting of fuse holders are prohibited Mains Lead When a three core mains lead with bare ends is provided it should be connected as follows Brown Mains live Blue Mains Neutral Green Yellow Earth WARNING THIS INSTRUMENT MUST BE EARTHED Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous Intentional interruption is prohibited General Service Handling Precautions Service work or calibration sh
22. ranges less than 1 on 5Hz 50Hz and 500kHz ranges all harmonics gt 25dB below fundamental on 5MHz range 0 2dB to 200kHz 2dB to SMHz Better than 99 to 200kHz lt 45ns 1 1 1 to 100kHz 10V unterminated Variable typically between 1 9 and 9 1 on top decade of each range frequency divided by 10 when Symmetry is selected MODULATION MODES Modulation can be used with all waveforms and at any frequency Sweep Sweep Mode Sweep Width Sweep Rate External Sweep Internal linear or logarithmic sweep Start and Stop frequencies displayed at a press of a button External linear Up to 1000 1 within each range Internal sweep rate adjustable from typically 20ms to 20s By signal applied by SWEEP IN OUT socket Amplitude Modulation Modulation Depth Variable 0 to 100 typical Modulation Frequency 400Hz internal DC to 100kHz external External Modulation By signal applied to COUNT AM IN socket OUTPUTS 509 Main Out Output Impedance 500 Amplitude 2mV to 20V peak peak open circuit 1mV to 10V peak peak into 50 in four switch selectable ranges with 20dB vernier control within each range Attenuator 0 20 40 or 60dB DC Offset Range 10V DC offset plus signal peak limited to 10V 5V into 50Q CLIP shows in display when offset signal peak exceeds 10V DC offset plus waveform attenuated proportionally by the attenuator 600 Main Out Alternative output socket
23. reased current capability to drive R24 and R76 When the symmetry button is depressed R24 and R76 are increased by a factor of 10 with the symmetry control in mid position decreasing the output frequency by a factor of 10 This allows a symmetry range of 10 1 IC2C refers the output of IC36B to the 12V rail IC4 and Q4 mirror this into the diode gate IC2A inverts the output of IC36B IC2B refers it to the 12V rail IC22 and Q18 mirror this into the diode gate Waveform Generation Range Selection and Triangle Amplifier Ranges 5kHz to 5MHz use decade steps of range capacitor The lower three ranges use a capacitance multiplier The capacitance multiplier steals current from the capacitor via R101 The triangle amplifier uses Q7 as a source follower and Q8 as a current source Q7 and Q8 are Idss matched Q9 and Q10 are emitter followers to give two low impedance outputs The stage has unity gain and the offset is trimmed by VR14 Waveform Generation Comparator and Aux Output IC5 operates as a window detector and determines the peak to peak amplitude of the triangle wave on the range capacitor which is approximately 1V Capacitors C15 to C20 compensate for comparator delay ensuring that the triangle wave amplitude remains constant with increase in frequency The two internal NAND gates in IC5 are wired as a flip flop to ensure positive switching of the comparator Q6 level shifts the output of IC5 to be about ground to drive the diod
24. s demonstrated by meeting the test limits of the following standards Emissions EN50081 1 1992 Generic emission standard for residential commercial and light industry Test methods and limits used were a EN55022 Conducted Class B b EN55022 Radiated Class B Immunity EN50082 1 1992 Generic immunity standard for residential commercial and light industry Test methods and limits used were a EN60801 2 1993 Electrostatic Discharge 8 kV air discharge b IEC801 3 1984 RF Field 3 V m IEC801 4 1988 Fast Transient 1 kV peak AC line 0 5kV peak signal lines Cautions To ensure continued compliance with the EMC directive the following precautions should be observed a connect the generator to other equipment using only high quality double screened cables b after opening the case for any reason ensure that all signal and ground connections are remade correctly before replacing the cover Always ensure all case screws are correctly refitted and tightened C In the event of part replacement becoming necessary only use components of an identical type see Parts List Installation Mains Operating Voltage The operating voltage of the instrument is shown on the rear panel Should it be necessary to change the operating voltage from 230V to 115V or vice versa proceed as follows 1 Disconnect the instrument from all voltage sources 2 Remove the 4 screws which hold the upper and lower case halves togethe
25. t not be negated by the use of an extension cord without a protective conductor When the instrument is connected to its supply terminals may be live and opening the covers or removal of parts except those to which access can be gained by hand is likely to expose live parts The apparatus shall be disconnected from all voltage sources before it is opened for any adjustment replacement maintenance or repair Any adjustment maintenance and repair of the opened instrument under voltage shall be avoided as far as possible and if inevitable shall be carried out only by a skilled person who is aware of the hazard involved If the instrument is clearly defective has been subject to mechanical damage excessive moisture or chemical corrosion the safety protection may be impaired and the apparatus should be withdrawn from use and returned for checking and repair Make sure that only fuses with the required rated current and of the specified type are used for replacement The use of makeshift fuses and the short circuiting of fuse holders is prohibited Do not wet the instrument when cleaning it The following symbols are used on the instrument and in this manual Caution refer to the accompanying documentation incorrect operation may damage the instrument Le terminal connected to chassis ground alternating current EMC This generator has been designed to meet the requirements of the EMC Directive 89 336 EEC Compliance wa
26. the output of the ramp generator with an offset current to drive the logging transistors IC13A and IC13B Temperature compensation of the log converter is by TDR1 which has a temperature coefficient of 0 396 C The log converter itself simply uses the exponential relationship between Vbe and collector current IC13 is a matched transistor array The right hand transistor is the logging transistor and its emitter is driven by the input voltage via the left hand transistor which compensates for the logging transistor Vbe The left hand transistor s collector current is defined by R16 and is held constant by IC3A its Vbe is therefore constant and so the input voltage at the junction of R19 and TDR1 is impressed across the Vbe of the logging transistor The logarithmic change in collector current of the logging transistor is converted into a voltage by IC3B The log converter is actually an antilog converter Digital Display IC30 is a microcontroller that provides frequency and voltage measurement and displays the results on the LCD In frequency measurement mode 1C29 A outputs the GATE signal which is controlled via the J START and K STOP inputs The GATE is synchronised to the positive edges of the input signal Whilst GATE is high IC30 counts the internal reference clock and IC29 B outputs the input signal divided by two which is also counted by IC30 When GATE goes low the frequency is calculated and displayed Voltage measurements are made via
27. trol to minimum adjust VR16 for 5mV at the main output Amplitude control to maximum adjust VR15 for 5mV at the main output Waveform Symmetry 5k range vernier at approximately 4 squarewave adjust VR8 for equal mark space ratio using the oscilloscope x10 X multiplier to increase resolution and the trigger slope switch 5M range vernier to approximately 005 to give 5kHz to 6kHz adjust VR5 for equal mark space ratio Frequency Calibration Connect the Frequency Counter to AUX output Select external count and apply a frequency standard to AM COUNT IN select 5 sec gate time if required and adjust VC2 through the front panel for the correct reading 2 ppm Select internal count and remove the frequency standard Dial fully clockwise 5kHz range note the reading on the internal frequency counter 500Hz range adjust VR12 for one tenth of the above reading 5 digits 5kHz range adjust verniers for 5Hz 50Hz range adjust VR36 for 00 05 Fit shorting link to TP1 and adjust the verniers for 18 0Hz on the external counter Adjust VR37 for 1 80 on the display Remove TP1 short 10 11 Sinewave Distortion Select sinewave 5k range 3kHz Adjust VR10 and VR11 for minimum distortion Adjust VR9 for the output to be symmetrical about OV AM 500k range approximately 300kHz sinewave modulation to minimum amplitude to maximum 20V pk pk Select AM check output drops to half 10V pk pk adjusted by VR18 Modulati
28. ut is low the charge on the capacitor will fall linearly producing the negative going triangle slope The triangle amplifier has unity gain and buffers the triangle wave on the multiplier capacitor to drive the comparator and output circuits The comparator operates as a window detector with fixed limit points set to the triangle peaks One of its two outputs drives the TTL CMOS output The other output is level shifted to drive the diode gate and squarewave shaper When the comparator output to the diode gate is high the triangle wave is positive going until this reaches approximately 1V when the comparator output switches low When the comparator output is low the triangle wave is negative going until it reaches approximately 1V when the comparator goes high and the cycle is repeated This basic function generator loop is shown by the double arrows in the block diagram Triangle and squarewave are generated simultaneously as shown To achieve the 500Hz 50Hz and 5Hz ranges the 5k range capacitor is multiplied by 10 100 or 1000 by the capacitor multiplier circuit The sinewave converter uses the non linear characteristics of a transistor pair to convert the triangle wave into a sinewave The selected function is amplified by the pre amp and applied to the amplitude control directly or via the amplitude modulator The signal is summed with the voltage from the DC offset control at the output amplifier which amplifies the signal up to 20V pe
29. vRie VRe a VR38 C 16 Main Board Calibration Points Part No 20205 0610 20613 0007 20661 0801 20670 0040 20670 0135 20670 0320 22040 0901 22115 0390 22219 0120 22225 0760 22312 0260 22315 0239 22315 0450 22520 0160 22573 0041 22573 9110 22575 0064 22575 0103 23185 0000 23185 6120 23202 0100 23202 0270 23202 0470 23202 0750 23202 0910 23202 1100 23202 1120 23202 1124 23202 1150 23202 1180 23202 1191 23202 1200 23202 1220 23202 1226 23202 1330 PCB ASSY MAIN 44912 0450 Description STUD M3 X 10 KFH M3 10ET WASHER SIL PAD TO220 PLAIN SPACER TRANSISTOR MTG TO5 HEATSINK TO5 48DEG C W CLIP GP02 FOR PCB MTG H SINKS HEATSINK PCB MTG 50MM PLAIN BEAD FERRITE FX1115 TRANSFORMER SWITCH ROCKER SPST R A SWITCHBANK X 13 FUSEHOLDER PCB MOUNT FUSE 125MA TL HRC FUSE 500mAT SUBMIN PCB MNT AC RECEP 10AMP R ANG HEADER 2 WAY STRAIGHT HEADER 36W STR SIL TIN HEADER 26 WAY 2X13 STR SKEL HEADER 16 WAY 2X8 STR SKELTN RES ZERO OHM RES 12M0J W25 CF RES 10ROF W25 MF 50PPM RES 27ROF W25 MF 50PPM RES 47ROF W25 MF 50PPM RES 75ROF W25 MF 50PPM RES 91ROF W25 MF 50PPM RES 100RF W25 MF 50PPM RES 120RF W25 MF 50PPM RES 124RF W25 MF 50PPM RES 150RF W25 MF 50PPM RES 180RF W25 MF 50PPM RES 191RF W25 MF 50PPM RES 200RF W25 MF 50PPM RES 220RF W25 MF 50PPM RES 226RF W25 MF 50PPM RES 330RF W25 MF 50PPM Parts List Position FOR PJ2 FOR IC25 26 FOR Q21 22 FOR Q21 22 FOR

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