HP-691A-692A-693A-694A-Manual 电路图.pdf

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1、I . : HP Archive . . This vintage Hewlett Packard document was preserved and distributed by www. Please visit us on the web ! . . On-line curator: Tony Gerbic RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 OPERATING AND SERVICE MANUAL MODELS 691A 6 9 2 A 6 9 3 A 6 9 4 A SWEEP OSCILLATORS SERIALS PR

2、EFIXED: 524-, AND 507- ALSO SERIALS PREFIXED 4 2 4 - , 4 2 9 - , 4 3 5 - , 500-, AND 501- SEE APPENDIX I W.HPARCHIVE.COM For Free Oistribution Only C o p y r i g h t HEWLETT-PACKARD C O M P A N Y 1965 1501 PAGE MILL R O A D , P A L 0 ALTO, C A L I F O R N I A , U.S.A 02280-1 Printed: OCT 1965 WWW.HP

3、ARCHIVE.COM RadioFans.CN 收音机爱 好者资料库 Models 691A/692A/693A/694A TABLE OF CONTENTS Table of Contents Section I GENERAL INFORMATION . 1 . 1 . Description . 1 . 1 0 . Instrument Options . 1 . 1 1 . Option 01 . 1 . 1 4 . Option 02 . 1 . 1 6 . Instrument Identification . 1 . 1 8 . BWO Tube Warranty . II I

4、NSTALLATION . 2 . 1 . Incoming Inspection . 2 . 3 . Preparation for Use . 2 . 4 . Power Requirements . 2 . 6 . 115/230 Volt Operation . 2 . 9 . Power Cable . 2 . 12 . Cooling . 2 . 1 4 . Air Filter . 2 . 1 6 . Magnetic Interference . 2 . 1 8 . Bench Use . 2 -2 1 . Rack Mounting . 2 . 2 4 . Repackagi

5、ng for Shipment . 1 1 1 OPERATION . 3 . 1 . 3 . 1 4 . 3 . 1 5 . 3 . 1 7 . 3 . 1 9 . 3 . 2 2 . 3 . 2 4 . 3 . 2 6 . 3 . 2 7 . 3 . 2 8 . 3 . 3 1 . 3 . 3 3 . 3 . 3 5 . 3 . 3 7 . 3 . 3 9 . 3 . 4 4 . 3 . 4 6 . 3 . 5 0 . 3 . 5 5 . 3 . 5 8 . 3 . 6 2 . 3 . 6 5 . 3 . 6 7 . 3 . 6 9 . 3 . 7 1 . 3 . 7 3 . 3 . 7

6、7 . 3 . 7 9 . 3 . 8 0 . 3 . 8 2 . 3 . 8 5 . 3 . 8 7 . 3 . 9 4 . 3 . 1 0 0 . 3 . 1 0 2 . 3 . 1 1 1 . 3 . 1 1 4 . 02280 . 1 Introduction . General Operating Information . Output Power Range . RF Input Limitation . BWO Life . Magnetic Interference . Controls. Connectors over entire frequency range 693A

7、: k20 Mc; 694A: 530 MC Marker.Sweep Sweeps from “Marker 1” to “Marker 2” fre- Range: Both settings continuously adjustable End-Point Accuracy: 691A,692A: i10 Mc; 693A: quency setting over entire frequency range i t 2 0 Mc; 694A: k30 MC AF Sweep Sweeps from lower to higher frequency, centered on CW s

8、etting Width: Continuously adjustable from zero to 10% of the frequency range Width Accuracy: 691A: 520% of A F being swept i2% of maximum AF; 692A, 693A, 694A: 510% of A F being swept il% of maximum A F 691A, 692A: *lo Mc; 693A: 520 Mc, 694A: i30 Mc Center- Frequency Accuracy: FREQUENCY MARKERS Two

9、 frequency markers, independently adjustable over entire frequency range, amplitude modulate RF output. Marker amplitude adjustable fromfront panel. Markers also available for external use. Accuracy: 691A, 692A: *lo Mc; 693A: *20 Mc; Resolution: Better than 0.05% at any frequency Marker Output: Tria

10、ngular pulse, typically -5V 694A: *30 Mc peak into 1000-ohm load C W OPERATION Single-frequency RF output selected by START STOP or MARKER 1 control, depending upon sweeD function selected. Accuracy: 691A, 692A: i10 Mc; 693A: *20 Mc; 694A: i30 Mc Preset Frequencies: Start-stop sweep endpoints and ma

11、rker frequencies can be used as four preset CW frequencies. RF OUTPUT CHARACTERISTICS With Temperature: + 0. O1o/c/o C With 10% Line Voltage Change: 691A, 692A: i 1 Mc; 693A, 694A: i 2 MC With 10-db Power Level Change: 691A, 692A: k500 kc; 693A, 694A: *1 MC Residual FM: 691A, 692A: 30 kc peak; 693A,

12、 694A: - INPUT Models 691A/692A/693A/694A D IR ECTlON A L DETECTOR VOLTAGE -TUNED OSCl LLkTOR / I START/CW 1 o-: 1 I I STOPIAF I o-: r I I I j I I I I I I I I I I I I I I I II INT ALC in others, the collector element is operated at a more positive potential than the helix, 4-14. Output power is a fu

13、nction of beam current. Beam current is primarily controlled by grid bias or by the current supplied to the cathode. A secondary control of beam current is anode voltage, but anode voltage also affects output frequency. Power output increases noticeably as the frequency is increased, peaks near the

14、center of the band and decreases slightly at the high end of the band. 4-15. Amplitude modulation is accomplished by a cur- rent generator in series with the BWO cathode. Cath- ode (beam) current can thus be controlled without changing the accelerating anode-cathode voltage, thus avoiding frequency

15、pulling. 4-1 WWW.HPARCHIVE.COM Section IV Figure 4-2 Models 69 1A/692A/6 93A/6 94A J12 I INPUT J12 OUTPUT FREQUENCY CONTBQL SECTION VOLTAGE -TUNED L - - _ _ _ 2 0 - s QL - 1 HELIX I COLLECTOR UNING VOLTAGE I l,AlV2,AIV3, AIV4 GENERATOR I - IVS,AIPl,AIP2 AIV6,AIVI,A4VIE I IHELIX - - I I I - FILTER i

16、OPTION 01 DIRECTIONAL DETECTOR A13 T m l II I I LOW PASS FLI GENERATOR VOLTAGE I A4VIA VI,V2,V3 WAVE OSCILLATOR v 4 NODE I GRID CATHODE I I TURN -ON DE LAY ASP23 BWO ANODE MODULATOR A2V48, AZV7E AMPLITUDE MODULATION SECTION ,- I -I I AMPLITUDE MODULAJION SECTION I- I I b OFF OFF d ALC AUTOMATIC LEVE

17、L ALC I CR6 ,A509 ASPIO ,A5011 - CONTROL AMPLIFIER ONd I A5VI,A5P16, A5017, A5P18, A5019 ,A5021, ON I E X T o c TPUT r+65V 12V REG :!UT I r- - - L _-_-_ J IPWR METER: ALc - +53V ALC INPUT +20V REG PEWLR SUPPLY SECTION - - - - HEATER TRANSISTOR EWO TUBE PROTECTIVE REG 7 POWER SUPPLY POWER SUPPLY - +2

18、75v REG 7 +156V REG -8lV REG -83V REG -3OOV REG LOW VOLTAGE POWER SUPPLIES A791 01, P2 03 - 0 6 I AZVI - A N I CKTS I K2, K4 4-2 WWW.HPARCHIVE.COM Figure 4-2. Block Diagram Showing Section Constituents 02280-1 Models 69 1A/6 92A/6 93A/6 94A Section IV Paragraphs 4-16 to 4-22 4-16. THE FREQUENCY CONT

19、ROL SECTION. 4-17. The Frequency Control Section determines the Sweep Oscillator output frequency. It generates a ramp that sweeps the RF output, or a d c volt- age that produces single frequency output, or a combination ramp and dc voltage for narrowband sweeps, or a combination of a dc voltage and

20、 an external signal to give external frequency modu- lation. The section also furnishes automatically repetitive or triggered sweeps, and permits manual sweeping by a front-panel control as well as in- dividual tuning of the frequency markers. The Frequency Control Section includes all of etched cir

21、cuit board A1 and parts of etched circuit boards A4 and A8. 4-18. The Frequency Control Section consists of a Tuning Voltage Generator and a Helix Voltage Generator. The Tuning Voltage Generator (Fig- ure 4-4) consists of a Ramp Generator that generates a linear, negative-going sawtooth, a Unity Gai

22、n Inverter that produces a mirror-image positive-going ramp, and a Ramp Combining Circuit that combines the two ramps and produces a continuously-adjustable ramp that is supplied to the Helix Voltage Gene- rator for application to the BWO helix. This ad- justable ramp controls the RF output connecto

23、r for testing purposes. The approximate ramp volt- age vs RF output frequency is shown by the graph in Figure 4-10. 4-19. The Frequency Control Section also supplies a positive-going sweep voltage for operating the X- system of graphic recorders and oscilloscopes, a penlift contact for lifting the p

24、en of a recorder be- tween sweeps, and an internal RF output blanking pluse that cuts off output power between sweeps. 4-21. THE RAMP GENERATOR. 4-22. GENERAL. The complete Ramp Generator (Figure 4-4) consists of Ramp Generator tube AlV1, Cathode Follower AlV2A with ramp limiting diodes AlCR8, AlCR9

25、, and AlCRlO on etched circuit Al. The ramp generator tube produces a linear, negative- going sawtooth of fixed amplitude and adjustable per- iod which is applied through switching circuits to the cathode follower and limiting diodes. These diodes establish the dc voltage limits at the start and sto

26、p ends of the ramp. The low-voltage end is clamped to near 0 volts by diodes AlCR9, AlCR10, and is ELECTRON BEAM 7 E L E C T R O N GUN- / HELIX yELI GRN CATHODE (OV) GRID (OV) AN ILU I REC -e- MAGNETIC FIELD -e - -*- I RF OUTPUT TO BALUN OR BLOCKING CAPACITOR )E HE (t300 TI I I I i ORN I COLLECTOR (

27、+50 TO +200V ABOVE HELIX, IF NOT CONNECTED TO HELIX) X t 2000V) * PTlC IAL INTER (+40 TO +220V) IAL CONNECTION 695A-0-1 Figure 4-3. The Backward-Wave Oscillator Tube 02280-1 4-3 WWW.HPARCHIVE.COM Section IV Figure 4-4 N 4 -4 n IL I- Models 691A/692A/693A/694A W z m P - U Y 4 4 9 n n z W 4 02280-1 WW

28、W.HPARCHIVE.COM Models 691A/692A/693A/694A Section IV Paragraphs 4-23 to 4-29 the RF sweep does not start until the ramp voltage crosses the + clamp voltage. adjusted by AlR35. The high-voltage end is c-dmped by AlCR8 to the regulated +156-volt (*4 volts) supply. The clamped ramp is then applied to

29、the START/CW side of the Ramp Combining Circuit and to the Unity Gain Inverter. 4-23. The Ramp Generator also supplies two output pulses during its flyback period: 1) a short negative pulse to the Blanking Switch to turn off the RF output during the flyback and, 2) a longer negative pulse to the Pen

30、lift Circuit that in turn provides a contact opening for lifting the pen of an external graphic re- corder between sweeps. 4-24. The ramp generator tube operates in a free- run mode for automatically repetitive sweeps, in a trigger mode to start a ramp from a trigger received, o r it can be switched

31、 off to permit manual frequency control. 4-25. RAMP GENERATOR OPERATION. Ramp Gen- erator tube A1V1, a phantastron, has a two-stage cycle: 1) plate current cutoff, and 2) plate conducting current and producing a negative-going voltage slope. 4-26. The switching grid (pin 7) switches the tube from on

32、e stage to the other. Bias more negative than about -5 volts cuts off plate current and causes the screen grid (half of which is located ahead of the switching grid) to conduct heavily. Bias more positive than about -5 volts allows l), plate current to flow and start a negative-going ramp and 2), sc

33、reen current to decrease causing screen voltage to rise and light the SWEEP ON indicator. Note that although the SWEEP ON indicator lights at the start of a ramp, 4-27. During AUTO operation, the switching grid receives plate current cutoff bias of about -13 volts from voltage divider AlR10, AlR11;

34、during trigger operation, -40 volt bias is supplied from divider AlR16, AlR17. The bias required to turn plate cur- rent on is received from one of three places: l) for manual trigger operation, pressing the TRIGGER MANUAL button applies a positive-going pulse from A1C7 directly to the switching gri

35、d; 2) for external triggering, an external negative pulse applied through C (Figure 4-5) to the control grid, causes aposi- tive -going pulse on the screen grid which is coupled through AIR16 to the switching grid; and 3) for AUTO operation, the positive-going plate flyback is delayed by AlR8, AlC4,

36、 and applied through AlCR4 to the switching grid. The delay allows the Helix Voltage Generator to recover between sweeps. After plate current has been turned on by any of the foregoing methods, increased screen voltage forward-biases AlCR7 and AlCR6. AlCR6 maintains a positive volt- age at switching

37、 grid pin 7 to keep AlVl plate current flowing and complete the ramp. 4-28. After triggering, a “feedback integrator” cir- cuit produces a linear, negative-going, voltage ramp at AlVl plate. In the circuit, shown simplified in Figure 4-6, C is an integrating capacitor initially charged to the grid-p

38、late voltage of AlVl (about +235 volts). 4-29. At the instant of triggering, plate current is turned on abruptly by switching grid pin 7. The Figure 4-5. Simplified Schematic Diagram of Ramp Generator in Trigger Mode 02280-1 4-5 Section IV Figure 4-6 -1 DSI 4: AIR12 : 47K Models 691 A/692A/693 A/694

39、A j!AlR2l I CYCLE SCREEN VOLTAGE DECREASES * I DURING RAMP. AT t73 VOLTS I I SWITCHING GRID TURNS OFF AND SCREEN GRID (PIN 6 ) SWITCHING GRID (PIN 7) PLATE (PINS) CONTROL GRID (PIN I) 0 AICR4 SCREEN TAKES ALL TUBE CURRENT. T I_ + 30 V- SWITCHING GRID TURNS OFF PLATE CUR RENT. SWITCHING GRID TURNS ON

40、 PLATE CURRENT. PLATE CURRENT STARTS; PLATE VOLTAGE DROPS. PLATE VOLTAGE FOLLOWS GRID VOLTAGE X TUBE GAIN. I t235V- +220v- PLATE CURRENT STOPS. PLATE VOLTAGE FLIES BACK. GRID RESPONDS TO DROP IN PLATE VOLTAGE. GRID CONTROLS PLATE CURRENT. II I II 1 85V Figure 4-6. Simplified Schematic Diagram of Ram

41、p Generator in Auto Mode 4-6 02280-1 WWW.HPARCHIVE.COM Models 691A/692A/693A/694A resultant sharp drop in plate voltage is coupled by grid-plate capacitor C to AlVl control grid and steps grid voltage enough negative to cause the control grid to assume control of tube current. Capacitor C then begin

42、s discharging through the tube and resistors AlR4, R4 at a rate determined by the gain of the tube and the RC time constant. 4-30. As plate voltage falls, screen current increases and screen voltage decreases. At a screen voltage of about +73V the reduced voltage at AlR16, AlR17 junction opens diode

43、s AlCR6 and AlCR7. A negative voltage from the AlR10, AlR11 junction is then ap- plied to switching grid pin 7 and cuts off plate current. Plate voltage, control grid voltage and tube current rise sharply. The increased tube current goes to the screen grid reducing screen voltage to a saturation lev

44、el of +30 volts. Capacitor C recharges through A1R7 and the circuit is ready for another cycle. 4-31. SWEEP TIMING. To provide the four decade sweep time ranges, the SWEEP TIME (SEC) selector connects a different capacitor in the circuit for each range. To provide continuous adjustment of time be- t

45、ween ranges, the VERNIER potentiometer adjusts the voltage supplied to the grid circuit; the more positive the voltage, the faster the grid return, and the shorter the sweep time. To prevent a large transient from occurring as one of the four capacitors is switched into the circuit, those capacitors

46、 not in use are con- nected into a charging circuit that holds their charge equal to the plate-grid voltage before triggering. 4-32. EXTERNAL TRIGGER CIRCUIT. In the exter- nal trigger input circuit, Figure 4-5, diode CR1 passes only negative-going pulses from the EXT input connector, while clamp di

47、odes AlCRl and A1CR2 limit the amplitude of the input pulse to 20 volts. Coupling diode AlCR3 is forward-biased by AlVl plate voltage between ramps to pass negative-going trigger pulses. After triggering, the plate voltage drops and back-biases AlCR3, disconnecting the trigger circuit from the integrator circuit. At the end of the plate flyback, plate voltage again forward- biases AlCR3 and the trigger circuit is reactivated. 4-33. MANUAL TRIGGER CIRCUIT. Manual triggers are generated by S5 (Figure 4-5). Before triggering, the junction of AlR16 and AlR17 is abo