HewlettPackard_8640B维修电路原理图.pdf

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1、TM 9-4935-601-14-7 fuse ratings are listed on the fuse compartment. To prevent damage to the instrument, make the line voltage selection before connecting line power. Also ensure that the line power cord is connected to a line power socket that is provided with a protective earth contact. SAFETY To

2、avoid the-possibility of damage to test equipment, read completely through each test before starting it. Make any preliminary control settings necessary for correct test equipment operation. COUNTER INPUT Do not apply a dc voltage or +15 dBm to COUNTER INPUT. SEMI-RIGID COAX While working with and a

3、round the semi-rigid coaxial cables in the generator, do not bend the cables more than necessary. Do not torque the RF connectors to more than 5 inch-pounds. xv/(xvi blank) RadioFans.CN 收音机爱 好者资料库 TM 9-1430-601-14-7 the part number is listed on the title page of this manual and on the rear cover of

4、the supplement. 1-5. Also listed on the title page of this manual is a Microfiche part number. This number can be used to order 4 x 6 inch microfilm transparencies of the manual. Each microfiche contains up to 60 photo duplicates of the manuals pages. The microfiche package also includes the latest

5、Manual Changes supplement as well as all pertinent Service Notes. 1-6. Instrument specifications are listed in Table 1-1. These specifications are the performance standards or limits against which the instrument can be tested. Paragraph 1-17 lists some supplemental performance characteristics. Suppl

6、emental characteristics are not specifications but are typical characteristics included as additional information for the user. 1-7. INSTRUMENTS COVERED BY MANUAL 1-8. This instrument has a two-part serial number. The first four digits and the letter comprise the serial number prefix. The last five

7、digits form the sequential suffix that is unique to each instrument. The contents of this manual apply directly to instruments having the same serial number prefixes as listed under SERIAL NUMBERS on the title page. 1-9. An instrument manufactured after the printing of this manual may have a serial

8、prefix that is not listed on the title page. This unlisted serial prefix indicates that the instrument is different from those documented in this manual. The manual for this instrument is supplied with a yellow Manual Changes supplement that contains change information that documents the differences

9、. 1-10. In addition to change information, the supplement may contain information for correcting errors in the manual. To keep this manual as current and accurate as possible, Hewlett-Packard recommends that you periodically request the latest Manual Changes supplement. The supplement for this manua

10、l is keyed to this 1-1 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 addresses are provided at the back of this manual. 1-74. TEST EQUIPMENT REQUIRED 1-75. Tables 1-2 and 1-3 list the test equipment and accessories required to check, adjust and repair the Model 8640B. If substitute equipment

11、 is used, it must meet the listed critical specifications. NOTE The safety classification of this instrument is Safety Class I. It has been designed and tested according to IEC Publication 348 Safety Requirements for Electronic Measuring Apparatus. The instruction manual contains information, warnin

12、gs, and cautions which must be followed by the user to ensure safe operation and to retain the instrument in safe condition. 1-7 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 accuracy depends on internal or external reference used. 2 TotalCounterReference Count=Resolution+Error Accuracy(1 co

13、unt)(INT or EXT) Internal Reference Error 200 ppm total range. Locked mode: 20 ppm by varying internal time base vernier. Stability: NormalLocked3 Time (after 2-hour10 ppm/10min0.05 ppm/hr warm-up) 2 ppm total4 Temperature50 ppm/ C(room ambient 15 to 350C) Line Voltage5 (+5% to -10% line1 ppm0.1 ppm

14、 voltage change) Load (with any passive1 ppm load change) Level Change (10 dB on output1 ppmNone level vernier)measurable 1% of selected Mode Changepeak deviation or (CW to FM)200 Hz which- ever is greater 1 In the External Doubler Band. the 8640B counter displays the actual doubled output frequency

15、. and the FM meter indicates the proper peak deviation. 2 When phase locked, Counter Resolution error is eliminated. 3 These specifications are given for the 8640B internal reference. When using an external reference, drift in the locked mode will depend on the external reference characteristics. 4

16、Phase lock may break due to temperature change (i.e., during warm-up). Simply relock at desired frequency. 5 This specification is for short term, transient line changes. 1-8 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 -5 dBm into 50, source impedance is approximately 500. Leakage: (With a

17、ll unused outputs terminated properly.) Leakage limits are below those specified in MIL-I-6181D. Furthermore, less than 3 V is induced in a 2-turn, 1-inch diameter loop 1 inch away from any surface and measured into a 50 receiver. This permits receiver sensitivity measurements to at least 0.03 V in

18、a shielded system. Level Accuracy: Using Using Top 10 dB ofFull Vernier RangeVernier Range Output Level+19 to-7 to-47 to+19 to (dBm)-7-47-137-145 Total AccuracyAdd as Indicated on1.5 dB2.0 dB2.5 dB0.5 dB Level Meter Note: Level Accuracy error consists of allowances for: meter accuracy, detector line

19、arity, temperature, flatness, attenuator accuracy, and twice the measurement error. All but the attenuator accuracy and the measurement error can be calibrated out with a power meter at a fixed frequency and a fixed vernier setting. MODULATION CHARACTERISTICS General Types: Internal AM and FM. Exter

20、nal AM, FM, and PULSE. Simultaneous AM and FM or PULSE and FM. Internal Modulation Sources: (independently adjustable output is available at front panel). Standard: Frequency: Fixed 400 Hz and 1 kHz, +2%. Output Level: Indicated 10 mV to 1 Vrms into 600. Optional: (Internal Variable Audio Oscillator

21、 Option 001). Frequency: Variable 20 Hz to 600 kHz, 10% in 5, decade continuous bands plus fixed 400 Hz and 1 kHz 2%. Output Level: 20 mV to 3V into 60012. Total Harmonic Distortion: 0.25%400 Hz and 1 kHz fixed tones 0.5% 20 Hz to 2 kHz 1.0% 2 kHz to 600 kHz Amplitude Modulation (AM specifications a

22、pply to the top 10 dB of output vernier range unless otherwise specified.) Depth: 0 to 100% for output level range of +13 dBm and below and for top 10 dB of vernier range.1 AM Rates: INT and EXT ac; 20 Hz to AM 3 dB band- width below. EXT dc; dc to AM 3 dB bandwidth below. AM 3 dB Bandwidth: (See Fi

23、gure 1-4). Frequency0 to50 to Bands50% AM90% AM 0.5 - 2 MHz20 kHz12.5 kHz 2 - 8 MHz40 kHz25 kHz 8 - 512 MHz60 kHz50 kHz 1 AM is possible above +13 dBm as long as the combination of the AM depth plus carrier output level does not exceed +19 dBm. 1-10 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-1

24、4-7 20 Hz to 250 kHz. External dc; dc to 250 kHz. FM Distortion: (at 400 Hz and 1 kHz rates) See Figure 1-6. 1% for deviations up to 1/8 maximum allowable. 3% for maximum allowable deviation. External FM Sensitivity: 1 volt peak yields maximum deviation indicated on PEAK DEVIATION switch with FM ver

25、nier at full CW position. External FM Sensitivity Accuracy: 6% from 15 to 35 C for FM excluding maximum peak deviation position. Maximum peak deviation position, 9% typically. 1 With 86408 in, LOCKED MODE, external FM is possible only for rates greater than 50 Hz. 1-11 RadioFans.CN 收音机爱 好者资料库 Model

26、8640BTM 9-4935-601-14-7 175 VA maximum. 71/2 ft. (2,29 m) power cable furnished with mains plug to match destination requirements. Weight: Net, 45 lb (20,4 kg). Dimensions:1 1 Dimensions are for general information only. If dimensions are required for building special enclosures, contact your HP off

27、ice. 1-12 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 A = Adjustment; T = Troubleshooting 1-13 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 -5 dBm Leakage: 3 V induced in a 2-turn, 1-inch diameter loop 1 inch away from any surface and measured into a 50n receiver. FM: dc coupled;

28、at least 40 kHz deviation for 1V input Audio SpectrumRange: 20 - 200 kHzHP 141T/P AnalyzerAmplitude Calibration:8552B/8556A Display Accuracy: 0.25 dB/dB but not more than 1.5 dB over 70 dB dynamic range Flatness: 0.2 dB Vertical Reference Scale: 10 dB/ division log, 2 dB/division (or less) log, and

29、linear display cali- bration Average Noise Level: 60 dB down for nominal specified inputs *P = Performance; A = Adjustments; T = Troubleshooting 1-17 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 A = Adjustments; T = Troubleshooting 1-18 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7

30、A = Adjustments; T = Troubleshooting 1-19 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 rotate the handle to the left. Gently pull the printed circuit voltage selector card from its slot and orient it so that the desired operating voltage appears on the top-left side (see Figure 2-1). Firmly

31、 push the voltage selector card back into its slot. Rotate the FUSE PULL handle to the right, install a fuse of the correct rating, and slide the fuse compartment cover to the right. A complete set of fuses is supplied with the instrument see ACCESSORIES SUPPLIED in Section I. NOTE The correct fuse

32、rating for the line voltage selected in listed on the line power module. More information about fuses is given in the table of replaceable parts in Section VI (reference designation is Fl). 2-1 1. Power Cable 2-12. In accordance with international safety standards, this instrument is equipped with a

33、 three-wire power cable. When connected to an appropriate power line outlet, this cable grounds the instrument cabinet. The type of power cable plug shipped with each instrument depends on the country of destination. Refer to Figure 2-2 for the part numbers of the power cable plugs available. Figure

34、 2-2. Power Cables Available. 2-2 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 c4nnected to a protective conductor of the power cord. This is accomplished by ensuring that the instruments internal earth terminal is correctly connected to the instruments chassis and that the power cord is wi

35、red correctly (see Service Sheet 22). 2-13. Mating Connectors 2-14. Mating connectors used with the Model 8640B should be either 50 ohm-type BNC male or Type N male connectors that are compatible with US MIL-C-39012. 2-15. Operating Environment 2-16. The operating environment should be within the fo

36、llowing limitations: Temperature .0 C to +55 C Humidity.95% relative Altitude.15,000 feet 2-17. A forced-air cooling system is used to maintain the operating temperature required within the instrument. The air intake and filter are located on the rear panel, and warm air is exhausted through perfora

37、tions in the right-hand side panel. When operating the instrument, choose a location that provides at least three inches of clearance at the rear and two inches clearance at the right side. The clearances provided by the plastic feet in bench stacking and the filler strips in rack mounting are adequ

38、ate for the top and bottom cabinet surfaces. 2-18. Bench Operation 2-19. The instrument cabinet has plastic feet and a foldaway tilt stand for convenience in bench operation. The tilt stand raises the front of the instrument for easier viewing of the control panel, and the plastic feet are shaped to

39、 make full-width modular instruments self- aligning when stacked. 2-20. Rack Mounting 2-21. A Rack Mounting Kit is available to install the instrument in a 19-inch rack. Rack Mounting Kits may be obtained through your nearest Hewlett-Packard Office by ordering HP Part Number 5060-8740. This kit cont

40、ains all necessary hardware and installation instructions for mounting the instrument on a rack with 19-inch spacing (see Figure 2-3). 2-22. STORAGE AND SHIPMENT 2-23. Environment 2-24. The instrument should be stored in a clean, dry environment. The following environmental limitations apply to both

41、 storage and shipment: Temperature .-40 C to +75 C Humidity.95% relative Altitude. +15 dBm to COUNTER INPUT. Figure 3-2. Front Panel Controls, Indicators, and Connectors (2 of 4) 3-3 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 level controlled by AUDIO OUTPUT LEVEL. NOTE With the Option 00

42、1 Variable Modulation Oscillator, AM OUTPUT and FM OUTPUT are in parallel. Parallel load should be -600 ohms. Figure 3-2. Front Panel Controls, Indicators, and Connectors (3 of 4) 3-4 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 load impedance is 1 k. Output for internal, 5 MHz time base re

43、ference, level is 3 Vrms into an open circuit; source impedance is 500 ohms. 3TIME BASE Reference INT/EXT: switch selects function of IN/OUT jack. INT position applies internal reference to jack. EXT position feeds external reference from jack to time base. NOTE Since the phase lock reference is the

44、 5 MHz time base, the Model 8640B can be phase locked to an external reference (such as another Model 8640B) by using the TIME BASE Reference jack and switch. 4Line Power Module: permits operation from 100, 120, 220 or 240 Vac. The number visible in window indicates nominal line voltage to which ins

45、trument must be connected (see Figure 2-1). Center conductor is safety earth ground. WARNING Any interruption of the protective (grounding) conductor inside or outside the instrument or disconnection of the protective earth terminal is likely to make the instrument dangerous. Intentional interruptio

46、n is prohibited. (See Section II). 5Serial Number Plate: first four digits of serial number comprise the prefix; last five digits form sequential suffix that is unique to each instrument. The plate also indicates any options supplied with instruments. Figure 3-3. Rear Panel Controls and Connectors 3

47、-6 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 FREQUENCY should read about .750000 MHz (the reading should shift one place to the left). Set COUNTER MODE EXPAND to X100; FREQUENCY should read about 500000 MHz (the reading should shift one additional place to the left with the decimal point

48、 and the seven no longer displayed; the OVERFLOW annunciator lamp should light). e. Set COUNTER MODE EXPAND 5 to OFF (buttons out). With RANGE 13 set as follows, FREQUENCY 6 should read approximately as shown: Figure 3-4. Operators Checks (2 of 5) 3-8 RadioFans.CN 收音机爱 好者资料库 Model 8640BTM 9-4935-601-14-7 the flickering should stop. Slowly adjust FINE TUNE; the FREQUENCY reading should not change. Adjust FREQUENCY TUNE 12 ; the FREQUENCY display should flash at about a 2 Hz rate and the reading should change (the reading should follow FREQUENCY TUNE). RF Out