HP-540A-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 INSTRUCTION AND O P E R A T I N G MANUAL F O R MODEL 540A TRANSFER OSCILLATOR Serial 492 and Above Copyright 1955 by

2、Hcwlett-Packard Company The information contained in this booklet i s intended for the operation and main- tenance of Hewlett-Packard equipment and i s not to be used otherwiseor reproduced without the writtenconsentof theHewlett- Packard Company. HEWLETT-PACKARD COMPANY 275 PAGE MILL ROAD, PAL0 ALT

3、O, CALIFORNIA, U. S. A. 540A003-2 RadioFans.CN 收音机爱 好者资料库 SPECIFICATIONS FOR I MODEL 540A TRANSFER OSCILLATOR GENERAL FREQUENCY RANGE: TYPE INPUT SIGNAL: INPUT SIGNAL LEVEL: ACCURACY: AUXILIARY EQUIPMENT: OSCILLATOR FUNDAMENTAL FREQ. RANGE: HARMONIC FREQ. RANGE: STABILITY: DIAL: VERNIER DIAL: OUTPUT

4、: ATTENUATOR RANGE: INPUT IMPEDANCE: AMPLIFIER 10 MC to 5,000 MC. (10 MC to 12,000 MC or high- e r with external detector. ) CW, AM, FM, or pulse. 50 mv to 5 v peak cw. 50v peak pulse, max. eq. CW power 1/2 w at 50 ohms. Depends on stability of unknown signal and pulse length - see text. Model 524B

5、Electronic Counter. Model 525B Frequency Converter Unit. Model 150A Oscilloscope (for pulse measure- ments). 100 MC to 220 MC. Above 12,000 MC. Less tkan 0.002?0 change per minute after 30 minute warmup. Six inch diameter, calibrated in 1 MC increments. Accuracy: fl/27?0. Mechanical: Approx. 9:l Ele

6、ctrical: Approx 2 v into 50 - Adjusted for optimum crystal harmonic generation. Approx. +125 parts per million Minimum attenuation is not more than 20 db and maximum attenuation is not less than 80 db at frequencies from 1 kmc to 5 kmc, below 1 kmc minimum attenuation and attenuation range in- creas

7、e. At 100 rnc minimum attenuation is at least 35 db. 50 ohms, SWR: 1.5 max. at 1 KMC; 3 max. at 5 KMC. GAIN: BANDWIDTH: HIGH FREQUENCY CONTROL: LOW FREQUENCY CONTROL: MAX. UNDJSTORTED OUTPUT: Adjustable, 40 db m a x 100 cycles to 2 megacycles. 3 db point adjustable from below 1 KC to above 2 MC. 3 d

8、b point switched from 100 cycles to below 10 KC then continuously adjustable to above 400 KC. 1 volt rms useable signal across 1,000 a load. J . . RadioFans.CN 收音机爱 好者资料库 SPECIFICATIONS FOR MODEL 540A TRANSFER OSCILLATOR (Contd) OS CLLLOS COPE (S e If Contained) FREQ. RANGE: VERTICAL DEFLECTION SENS

9、ITIVITY: HORIZONTAL SWEEP: TUBE: MISCELLANEOUS CONNECTORS : SIZE: WEIGHT: POWER SUPPLY: ACCESSORIES FURNISHED: ACCESSORIES AVAILABLE: AUXILIARY EQUIPMENT: 100 cps to 200 KC. 5 MV rms per inch. External, lv per inch, frequency response 20 cps to 5 KC; Internal sine wave, at power supply frequency wit

10、h phase control. 2 inch diameter. Input, type N; all others type BNC. Cabinet Mount: 20-1/2 wide, 12-1/211 high, 15 - 1 /4 deep. Rack Mount: 19 wide, 10-1/2 high, 15- 1/4 deep. Cabinet Mount: 42 lbs. ; shipping weight 63 lbs. Rack Mount: 35 lbs. ; shipping weight 56 lbs. 115/230v rms *lo%, 50/1,000

11、cps, approximately 11owatts. eAC-16K Cable Assembly, 4 feet of RG-58/U 50 ohm coaxial cable terminated at each end with UG-88/U Type BNC male connectors. QAC-16C Cable Assembly, 6 feet of RG-9A/U 50 ohm coaxial cable terminated at one end with a UG-21B/U Type N Male connector and with a UG-23B/U Typ

12、e N female connector at the other. (For use at frequencies below 4,000 MC. ) AC-16D Cable Assembly, 44 inches of RG-58/U 50 ohm coaxial cable terminated at one end only with a UG-88/U Type BNC male connector. $2.65 AC-16F Cable Assembly 6 feet of RG-9A/U 50 ohm coaxial cable terminated at each end w

13、ith UG-21B/U Type N male connectors. use at frequencies below 4,000 MC. ) AC-l6Q Cable Assembly, 6 feet of specially treated RG-SA/U 50 ohm coaxial cable term- inated at each end with UG-ZlB/U Type N male connectors. Each cable is tested and selected for minimum SWR at frequencies above 4,000 MC . (

14、For Model 524B Electronic Counter, cabinet mount. 0 Model 524BR Electronic Counter, rack mount. Model 525B Frequency Converter Unit, 100-220 MC. i Model 440A Detector Mount. TABLE OF CONTENTS MODEL 540A TRANSFER OSCILLATOR Page Section I GENERAL DESCRIPTION 1-1 Description . . . . . . . . . . . . .

15、. . . . . 1-1 1-2 Principle of Operation . . . . . . . . . . . . . 1-1 1-3 Accuracy of Measurement . . . . . . . . . . . 1-2 1-4 Accessories Furnished . . . . . . . . . . . . 1-2 Section I1 OPERATING INSTRUCTIONS 2-1 2 -2 2 -3 2 -4 2 -5 2 -6 2 -7 2 -8 2 -9 2-10 Ins tallation . . . . . . . . . . . .

16、. . . . . . Power Line Voltage and Frequency . Frequency Measurement. General . . . . . . . Measuring CW Frequencies . . . . . . . . . . Measuring Frequency-Modulated R-F Signals . . . Measuring Pulsed R-F Signals . . . . . . . . . Inc r eas ing Sensitivity . . . . . . . . . . . . . . Operating the

17、540A Above 5 KMC- The Frequency Control Jack on the Rear Panel . . Measurement Precautions . . . . . . . . . . . Special Applications of the 540A Transfer Oscillator . . . . . . . . . . . . . . . . . . 2-1 2-1 2-1 2-6 2 -9 2-11 2-15 2-15 2-17 2-17 Section 1 1 1 THEORY OF OPERATION 3-1 BlockDiagram .

18、 . . . . . . . . . . . . . . . 3-1 3 -2 100 to 220 MC Oscillator . . . . . . . . . . . . 3-2 3-3 Input Attenuator . . . . . . . . . . . . . . . . 3-3 Mixer . 3-3 3 -4 3-5 Video Amplifier . . . . . . . . . . . . . . . . 3-3 3-6 Vertical Amplifier for the Oscilloscope . . . . . 3-4 3-7 Horizontal Ampl

19、ifier and Sweep Circuits . . . . . 3-4 3-8 Power Supply . . . . . . . . . . . . . . . . 3-5 Section IV SERVICE INSTRUCTIONS 4-1 Removing the Instrument Cabinet . . . . . . . . 4-1 4-2 Tube Replacement . . . . . . . . . . . . . . . 4-1 4-3 Checking and Adjusting the Power Supply . . . . . 4-2 Horizon

20、tal Positioning . . . . . . . . . . . . . 4-4 4-5 Calibrating the Main Tuning Dial . . . . . . . . 4-4 4-6 Replacing the Crystal Diode Mixer . . . . . . . 4-5 4-7 Trouble Shooting . . . . . . . . . . . . . . . 4-5 4-4 Adjusting the Oscilloscope Vertical and . Section V TABLE OF REPLACEABLE PARTS 5 -

21、2 SECTION I GENERAL DESCRIPTION 1-1 DESCRIPTION The Model 540A Transfer Oscillator is a precision frequency- measuring instrument which can be used with the 524B Elec- tronic Counter and 525B Frequency Converter to measure frequen- cies from 100 megacycles to over 5,000 megacycles with frequency- st

22、andard accuracy and with better than 0. 1-volt sensitivity. Types of r-f signals that can be measured include continuous-wave, fre- quenc y -modulate d, amplitude -modulated and pulse -modulate d signals, and signals containing troublesome amounts of noise. In addition, the residual frequency-modula

23、tion in c -w signals, the limits of incidental frequency-deviation in amplitude -modulated signals and the limits of frequency deviation in frequency-modulated signals can also be measured. As a result of the Transfer Oscillator method of making a frequency measurement and the use of an oscilloscope

24、 to observe the beat- frequency, each of the above types of signals is easily distinguished and in all cases the zero-beat is quickly determined. By using two 440A Tunable Detectors with the 540A, the range of fre- quency measurement is extended to above 12,400 megacycles with the same 0. 1-volt sen

25、sitivity. By amplifying the harmonic output from the 540A and using a suitable external crystal harmonic gen- erator, it is possible to extend the upper frequency measurement range indefinitely, retaining the frequency-standard accuracy and high sensitivity. The 540A can also be used without a frequ

26、ency counter to measure frequencies to about 2,000 megacycles to 1/2% accuracy and to higher frequencies when the frequency of the input signal is known approximately. 1-2 PRINCIPLE OF OPERATION To determine the frequency of an unknown signal, the 540A beats the unknown signal against a harmonic of

27、a very accurately known fundamental frequency. The harmonic number is determined and the fundamental frequency is multiplied by the harmonic number to give the exact frequency of the input signal. How this system measures frequency can be described by reference to Figure 2. The Transfer Oscillator g

28、enerates a stable signal, adjustable in frequency from 100 to 220 megacycles, which is continuously monitored to 1 part/million accuracy by the frequency counter. 1-1 Harmonics of the Transfer Oscillator are then compared in an in- ternal mixer with the frequency to be measured, using the oscillo- s

29、cope contained in the Transfer Oscillator to observe the difference frequency. By suitable adjusting the Transfer Oscillator frequency, a zero-beat can be obtained between a Transfer Oscillator harmonic and any unknown frequency applied to the input. When the zero-beat is obtained, the unknown frequ

30、ency is determined merely by multi- plying the reading on the frequency counter by the proper harmonic number. equation or the nomograph included in paragraph 2-3. I the proper number is unknown, it can be found by simple 1-3 ACCURACY OF MEASUREMENT 1-4 The very high degree of setability, stability

31、and the resolution of the 540A Transfer Oscillator are all such that the accuracy of the 524B Electronic Counter is fully utilized over the greatly extended fre- quency range. In practice very few r-f signals are stable enough to be measured with such accuracy; thus the instability of the sig- nal b

32、eing measured becomes the greatest accuracy-limiting factor. It is possible with the 540A Transfer Oscillator to read frequency as close as 2 parts/lO million. For measurement of very stable, noise-free c-w signals the accuracy of measurement approaches 1 part/million. When measuring pulsed r -f sig

33、nals accuracy de- pends to some extent upon the pulse length. obtainable on a stable, pulsed carrier of 1000 megacycles are approximately 3 parts/million for a 10 microsecond pulse and 10 parts/million for a 2. 5 microsecond pulse. Typical accuracies ACCESSORIES FURNISHED i The 540A Transfer Oscilla

34、tor includes as part of the equipment, two 6 coaxial-cable jumpers with BNC connectors for use between jacks on the front panel, and one 4 ft. coaxial cable with BNC con- nectors for connecting the Transfer Oscillator to external equip- ment. 1-2 540A TRANSFER OSCILLATOR -1 - - - - - - - - - - - - -

35、 - _ I r- I DIFFERENCE FREQ. AMPLIFIER OSCl LLOSCOPE I I I I OSCILLATOR I I - J 100-200 MC L - - - - - - I I I I I - 524 B FREQUENCY COUNTER AND 5258 100-220 MC CONVERTER J Fig. 2. Simplified Block Diagram of the -hp- 540A Transfer Oscillator 1 -3 1-4 J . SECTION I1 OPERATING INSTRUCTIONS 2-1 INSTAL

36、LATION No special operating precautions are necessary for installing the 540A except when it is to be operated near vibrating machinery. Even though the 540A is not prone to microphonics, its extreme resolution makes very small frequency changes readily observable, and the effects of vibration may b

37、ecome apparent. machines create a disturbance in frequency measurement, the 540A should be shock-mounted or placed on soft shock-absorbing mate- rial. If vibrating 2-2 POWER LINE VOLTAGE AND FREQUENCY The 540A can be operated from either 115-volt or 230-volty 50 to 1000-cycle power lines. As shipped

38、 from the factory the 540A is wired for operation on 115-volts. volts, the power -transformer primary windings must be connected in series instead of in parallel as shown in the schematic diagram, and the 1.25 amp slow blow fuse should be replaced with a 0.6 amp slow blow fuse., J f the 540A is to b

39、e operated at a line frequency higher than 120 cycles the PHASE control for the self-contained oscilloscope will not be effective. It is desirable in this case to adjust the value of one capacitor in the PHASE control circuit, as described in para- graph 3-7, so that the PHASE control will be effect

40、ive at the higher line frequency in use. The three-conductor power cord for the 540A is terminated by a polarized, three-contact plug recommended by the National Elec - trical Manufacturers Association for protection of operating personnel. The third contact is an offset, round prong added to a stan

41、dard two-blade a-c connector which grounds the instrument chassis when used with a matching receptacle. To use this connector in a standard, two-contact a-c receptacle, the appropriate adapter must be provided by the operator, or the round prong can be removed from the connector. If it is to be oper

42、ated on 230- 2-3 FREQUENCY MEASUREMENT, GENERAL This section gives step-by-step operating instructions for measur- ing the frequency of the three most common types of r-f signals: continuous -wave, frequency-modulated and pulsed signals. Each procedure is accompanied by illustrations of an instrumen

43、t set-up and oscillograms showing typical beat-frequency representations. 2-1 At the end of the section are instructions for increasing the fre- quency range and sensitivity of the 540A. When tuning the 540A to measure frequency, first determine the fundamental frequency required, turn the frequency

44、 dial close to this frequency. frequency response on the oscilloscope, then tune the FINE VER- NIER to obtain the zero-beat indication. The range of the FINE VERNIER is small so the COARSE VERNIER should be tuned as close as possible to the zero-beat with the FINE VERNIER set to : the center of its

45、range. Tune the COARSE VERNIER to obtain a beat- When measuring any unknown signal for the first time, one of two conditions arises: the frequency of the signal is completely unknown, or, its approximate frequency is known and can be divided by some harmonic number to arrive at the fundamental frequ

46、ency to which the 540A must be tuned. If the frequency of the signal is com- pletely unknown, a harmonic must be determined by locating two adjacent fundamental frequencies with the 540A which result in beat-frequency indications with the input signal. fundamental frequencies, the harmonics that cre

47、ate the beats, and the exact frequency of the unknown signal can be determined. The equations for calculating the unknown frequency, and the harmonics, are as follows: From these two i I * - Product of Two Adjacent Fundamental Freqs. Difference Between Same Two Fundamental Freqs. Frequency of - Inpu

48、t Signal Harmonic Number = Lower Fundamental Frequency of Higher Funda- mental Frequency Difference Between Same Two Fundamental Freqs. . . I . Harmonic Number - Higher Fundamental Frequency of Lower Funda- mental Frequency - Difference Between Same Two Fundamental Freqs. To obtain accurate answers

49、with these equations the fundamental frequencies must be read to 0. 0170, or better. multiplication can then be carried out with a slide rule when greater than slide-rule accuracy is not required in the answer. the accuracy of a calculated answer select the next higher or lower adjacent fundamental frequency that results in a beat-frequency, an