
Theory of Operation
3- 38
2715 Spectrum Analyzer Service Manual
Log Amplifier
The Log Amplifier system is a high performance, intermediate amplifier system
that provides display laws of linear detection and logarithmic detection of the
incoming signal. The log display has scale factors of 10 dB/div, 5 dB/div, and
1 dB/div. The linear mode has the ability to magnify the top portion of the
waveform to enhance the measurement capability. The module also contains an
FM detector, which, when used with the built in audio amplifier, can be used to
monitor the modulated input signal for enhanced signal identification. The audio
amplifier can also be used to monitor the output of the displayed waveform
regardless of the video source. There is an alternate audio input for the push
button clicks generated by the system controller. This audio signal is also used
for the vertical amplitude reference, to check the sweep speed, and for internal
triggers. An amplitude limited output is available for the period counter for
determining the actual frequency of the signal present in the IF system. External
video inputs are provided for the use of external detectors and the rear panel. A
provision is made for clamping the display when the 1st LO is tuned out-of-
band. Frequency dependent amplitude (flatness) correction is also performed on
this board.
The Log Amplifier system is configured by using a 4.5 by 8.75 circuit board
mounted in the card cage. The Microprocessor interface is through three 8 bit
shift registers.
The signal level at the Log Amplifier board (J190) for full screen deflection is
--10 dBm. The first stage of the Log Amplifier is an amplifier that provides gain
between 18 dB and 24 dB, depending on the frequency of the 1st LO. The
amplifier is adjusted such that the gain is 18 dB at low frequencies and is up to
24 dB at the high end of the frequency range, because the frequency dependent
amplitude error is always greater at the higher frequencies. The feedback is
adjusted by changing the amount of current flowing through PIN diodes CR290
or CR291. The correction voltage, SWPSLOPE, reflects the frequency of the 1st
LO. Provision for a second correction voltage from a future Digital Signal
Processing module is included. This second correction voltage, which provides
an interpolated voltage, will be derived from a flatness table. At present, only
SWPSLOPE is used.
The output of the first stage, a gain slope amplifier, is then fed to a two pole
noise filter to limit the noise to 5 MHz and to provide two more poles of 5 MHz
bandwidth resolution filtering. The output of this filter is then sent to the log
stages through a set of jumpers so the signal can be broken for calibration
purposes and buffer amplifier Q170 (in a common base configuration) to form an
auxiliary IF output.
Hardware
Flatness Error Correction
Noise Filter
Содержание 2715
Страница 4: ......
Страница 16: ...Service Safety Summary xii 2715 Spectrum Analyzer Service Manual ...
Страница 152: ...Theory of Operation 3 94 2715 Spectrum Analyzer Service Manual ...
Страница 254: ...Adjustment Procedures 5 66 2715 Spectrum Analyzer Service Manual ...
Страница 292: ...Options 7 4 2715 Spectrum Analyzer Service Manual ...
Страница 436: ...Replaceable Electrical Parts 8 144 2715 Spectrum Analyzer Service Manual ...
Страница 438: ...Diagrams 9 2 2715 Spectrum Analyzer Service Manual ...
Страница 445: ...Replaceable Mechanical Parts 2715 Spectrum Analyzer Service Manual 10 7 1 2 3 4 5 6 7 8 9 10 11 12 Figure 10 1 Cabinet ...
Страница 463: ...Replaceable Mechanical Parts 2715 Spectrum Analyzer Service Manual 10 25 1 2 3 4 5 6 7 8 9 Figure 10 6 Accessories ...
Страница 464: ...Replaceable Mechanical Parts 10 26 2715 Spectrum Analyzer Service Manual ...
Страница 468: ......
Страница 474: ...Service Safety Summary vi 2715 Spectrum Analyzer Service Manual ...
Страница 481: ...9 5 2715 Spectrum Analyzer Service Manual 2715 1 RF ATTENUATOR A18 ...
Страница 483: ...9 7 2715 Spectrum Analyzer Service Manual 1 1ST CONVERTER A16A1 2715 ...
Страница 485: ...2715 Spectrum Analyzer Service Manual 9 9 1 RF INPUT A16A2 2715 ...
Страница 487: ...9 11 2715 Spectrum Analyzer Service Manual 1 YIG BUFFER AMPLIFIER A17 2715 ...
Страница 489: ...9 13 2715 Spectrum Analyzer Service Manual 2715 1 1ST LO INTERFACE A19A1 ...
Страница 490: ...2715 Spectrum Analyzer Service Manual 9 14 ...
Страница 491: ...9 15 2715 Spectrum Analyzer Service Manual 2715 2 1ST LO A19 ...
Страница 493: ...9 17 2715 Spectrum Analyzer Service Manual Figure 1 9 A12A1 Phaselock CFC back ...
Страница 495: ...9 19 2715 Spectrum Analyzer Service Manual PHASELOCK CFC BOARD SIGNAL INTERCONNECT A12A1 2715 0 ...
Страница 496: ...2715 Spectrum Analyzer Service Manual 9 20 ...
Страница 497: ...9 21 2715 Spectrum Analyzer Service Manual 2715 PHASELOCK CFC A12A1 1 ...
Страница 498: ...2715 Spectrum Analyzer Service Manual 9 22 ...
Страница 499: ...9 23 2715 Spectrum Analyzer Service Manual 2715 2 PHASELOCK CFC A12A1 ...
Страница 500: ...2715 Spectrum Analyzer Service Manual 9 24 ...
Страница 501: ...9 25 2715 Spectrum Analyzer Service Manual PHASELOCK CFC A12A1 2715 3 ...
Страница 502: ...2715 Spectrum Analyzer Service Manual 9 26 ...
Страница 504: ...2715 Spectrum Analyzer Service Manual 9 28 ...
Страница 506: ...2715 Spectrum Analyzer Service Manual 9 30 ...
Страница 507: ...9 31 2715 Spectrum Analyzer Service Manual 2715 6 PHASELOCK CFC POWER SUPPLY A12A1 ...
Страница 509: ...9 33 2715 Spectrum Analyzer Service Manual 2715 1 HF VCO A12A2 ...
Страница 511: ...9 35 2715 Spectrum Analyzer Service Manual LF VCO A12A3 1 2715 ...
Страница 514: ...2715 Spectrum Analyzer Service Manual 9 38 ...
Страница 515: ...9 39 2715 Spectrum Analyzer Service Manual SIGNAL INTERCONNECT RF MOTHER BOARD A14 0 2715 ...
Страница 516: ...2715 Spectrum Analyzer Service Manual 9 40 ...
Страница 517: ...9 41 2715 Spectrum Analyzer Service Manual RF MOTHER A14 1 2715 ...
Страница 518: ...2715 Spectrum Analyzer Service Manual 9 42 ...
Страница 519: ...9 43 2715 Spectrum Analyzer Service Manual 2 RF MOTHER A14 2715 ...
Страница 520: ...2715 Spectrum Analyzer Service Manual 9 44 ...
Страница 521: ...9 45 2715 Spectrum Analyzer Service Manual 3 RF MOTHER A14 2715 ...
Страница 522: ...2715 Spectrum Analyzer Service Manual 9 46 ...
Страница 523: ...9 47 2715 Spectrum Analyzer Service Manual 2715 4 RF MOTHER A14 68 1 R213 ...
Страница 526: ...2715 Spectrum Analyzer Service Manual 9 50 ...
Страница 527: ...2715 Spectrum Analyzer Service Manual 9 51 2715 0 SIGNAL INTERCONNECT A28 VIDEO DEMOD BOARD ...
Страница 528: ...9 52 2715 Spectrum Analyzer Service Manual ...
Страница 529: ...2715 Spectrum Analyzer Service Manual 9 53 2715 1 A28 DEMOD 1 VIDEO DEMOD BOARD NOT USED ...
Страница 530: ...9 54 2715 Spectrum Analyzer Service Manual ...
Страница 534: ...2715 Spectrum Analyzer Service Manual 9 58 ...
Страница 535: ...2715 Spectrum Analyzer Service Manual 9 59 SIGNAL INTERCONNECT A11 DIGITAL OPTIONS BOARD 0 2715 ...
Страница 536: ...9 60 2715 Spectrum Analyzer Service Manual ...
Страница 537: ...2715 Spectrum Analyzer Service Manual 9 61 1 MICROPROCESSOR BUS INTERFACE DIGITAL OPTIONS BOARD A11 2715 ...
Страница 538: ...9 62 2715 Spectrum Analyzer Service Manual ...
Страница 539: ...2715 Spectrum Analyzer Service Manual 9 63 2715 2 PHASE LOCKED LOOP EPROM AND NVRAM A11 DIGITAL OPTIONS BOARD ...
Страница 540: ...9 64 2715 Spectrum Analyzer Service Manual ...
Страница 541: ...2715 Spectrum Analyzer Service Manual 9 65 REAL TIME CLOCK AND RS232 INTERFACE DIGITAL OPTIONS BOARD A11 3 2715 ...
Страница 542: ...9 66 2715 Spectrum Analyzer Service Manual ...
Страница 543: ...2715 Spectrum Analyzer Service Manual 9 67 4 VIDEO GATING LOGIC AND GPIB INTERFACE DIGITAL OPTIONS BOARD A11 2715 ...
Страница 544: ...9 68 2715 Spectrum Analyzer Service Manual ...
Страница 545: ...2715 Spectrum Analyzer Service Manual 9 69 2715 IF GATE A11 DIGITAL OPTIONS BOARD 5 ...
Страница 548: ...2715 Spectrum Analyzer Service Manual 9 72 ...
Страница 549: ...9 73 2715 Spectrum Analyzer Service Manual 0 SIGNAL INTERCONNECT VARIABLE RES0LUTION BOARD A13 2715 ...
Страница 550: ...2715 Spectrum Analyzer Service Manual 9 74 ...
Страница 551: ...9 75 2715 Spectrum Analyzer Service Manual 1 VARIABLE RESOLUTION A13 2715 ...
Страница 552: ...2715 Spectrum Analyzer Service Manual 9 76 ...
Страница 553: ...9 77 2715 Spectrum Analyzer Service Manual 2 A13 VARIABLE RESOLUTION 2715 ...
Страница 554: ...2715 Spectrum Analyzer Service Manual 9 78 ...
Страница 555: ...9 79 2715 Spectrum Analyzer Service Manual 3 VARIABLE RESOLUTION A13 2715 ...
Страница 556: ...2715 Spectrum Analyzer Service Manual 9 80 ...
Страница 557: ...9 81 2715 Spectrum Analyzer Service Manual 4 VARIABLE RESOLUTION A13 2715 ...
Страница 560: ...2715 Spectrum Analyzer Service Manual 9 84 ...
Страница 561: ...9 85 2715 Spectrum Analyzer Service Manual 2715 0 SIGNAL INTERCONNECT A23 RF OPTION BOARD ...
Страница 562: ...2715 Spectrum Analyzer Service Manual 9 86 ...
Страница 563: ...9 87 2715 Spectrum Analyzer Service Manual 1 RF OPTION A23 2715 ...
Страница 564: ...2715 Spectrum Analyzer Service Manual 9 88 ...
Страница 565: ...9 89 2715 Spectrum Analyzer Service Manual 2715 2 RF OPTION A23 ...
Страница 566: ...2715 Spectrum Analyzer Service Manual 9 90 ...
Страница 567: ...9 91 2715 Spectrum Analyzer Service Manual 2715 3 RF OPTION A23 ...
Страница 569: ...9 93 2715 Spectrum Analyzer Service Manual Figure 1 24 A7 Log Amp back ...
Страница 571: ...9 95 2715 Spectrum Analyzer Service Manual 2715 LOG AMP BOARD A7 SIGNAL INTERCONNECT 0 ...
Страница 572: ...2715 Spectrum Analyzer Service Manual 9 96 ...
Страница 573: ...9 97 2715 Spectrum Analyzer Service Manual 2715 LOG AMP BOARD A7 NOT USED 1 ...
Страница 574: ...2715 Spectrum Analyzer Service Manual 9 98 ...
Страница 575: ...9 99 2715 Spectrum Analyzer Service Manual 2715 LOG AMP BOARD A7 2 ...
Страница 576: ...2715 Spectrum Analyzer Service Manual 9 100 ...
Страница 577: ...9 101 2715 Spectrum Analyzer Service Manual LOG AMP BOARD A7 2715 3 ...
Страница 578: ...2715 Spectrum Analyzer Service Manual 9 102 ...
Страница 579: ...9 103 2715 Spectrum Analyzer Service Manual 2715 LOG AMP BOARD A7 4 ...
Страница 580: ...2715 Spectrum Analyzer Service Manual 9 104 ...
Страница 581: ...9 105 2715 Spectrum Analyzer Service Manual 2715 LOG AMP BOARD A7 5 ...
Страница 582: ...2715 Spectrum Analyzer Service Manual 9 106 ...
Страница 583: ...9 107 2715 Spectrum Analyzer Service Manual 2715 A7 LOG AMP BOARD 6 ...
Страница 585: ...9 109 2715 Spectrum Analyzer Service Manual 0 A21 SIGNAL INTERCONNECT REFERENCE OSCILLATOR BOARD 2715 ...
Страница 586: ...2715 Spectrum Analyzer Service Manual 9 110 ...
Страница 587: ...9 111 2715 Spectrum Analyzer Service Manual 2715 1 REFERENCE OSCILLATOR A21 ...
Страница 588: ...2715 Spectrum Analyzer Service Manual 9 112 ...
Страница 589: ...9 113 2715 Spectrum Analyzer Service Manual 2715 2 REFERENCE OSCILLATOR A21 ...
Страница 591: ...9 115 2715 Spectrum Analyzer Service Manual Figure 1 28 A10 Microprocessor back ...
Страница 593: ...9 117 2715 Spectrum Analyzer Service Manual 0 SIGNAL INTERCONNECT A10 MICROPROCESSOR BOARD 2715 ...
Страница 594: ...2715 Spectrum Analyzer Service Manual 9 118 ...
Страница 595: ...9 119 2715 Spectrum Analyzer Service Manual CLOCK CPU AND INTERRUPT CONTROLLER MICROPROCESSOR BOARD A10 1 2715 ...
Страница 596: ...2715 Spectrum Analyzer Service Manual 9 120 ...
Страница 597: ...9 121 2715 Spectrum Analyzer Service Manual RAM A10 MICROPROCESSOR BOARD 2 2715 ...
Страница 598: ...2715 Spectrum Analyzer Service Manual 9 122 ...
Страница 599: ...9 123 2715 Spectrum Analyzer Service Manual ROM A10 MICROPROCESSOR BOARD 3 2715 ...
Страница 600: ...2715 Spectrum Analyzer Service Manual 9 124 ...
Страница 601: ...9 125 2715 Spectrum Analyzer Service Manual 2715 CONTROL A10 MICROPROCESSOR BOARD 4 ...
Страница 602: ...2715 Spectrum Analyzer Service Manual 9 126 ...
Страница 603: ...9 127 2715 Spectrum Analyzer Service Manual 5 FREQUENCY COUNTERS MICROPROCESSOR BOARD A10 2715 ...
Страница 604: ...2715 Spectrum Analyzer Service Manual 9 128 ...
Страница 605: ...9 129 2715 Spectrum Analyzer Service Manual FREQUENCY COUNTERS AND I O SUBSYSTEM A10 MICROPROCESSOR BOARD 6 2715 ...
Страница 606: ...2715 Spectrum Analyzer Service Manual 9 130 ...
Страница 607: ...9 131 2715 Spectrum Analyzer Service Manual COUNTER INPUT SELECT MICROPROCESSOR BOARD A10 7 2715 ...
Страница 608: ...2715 Spectrum Analyzer Service Manual 9 132 ...
Страница 609: ...9 133 2715 Spectrum Analyzer Service Manual CONNECTORS AND DECOUPLING A10 MICROPROCESSOR BOARD 8 2715 ...
Страница 613: ...9 137 2715 Spectrum Analyzer Service Manual 1 2715 SIGNAL INTERCONNECT A9 DISPLAY STORAGE BOARD ...
Страница 614: ...2715 Spectrum Analyzer Service Manual 9 138 ...
Страница 615: ...9 139 2715 Spectrum Analyzer Service Manual NOT USED NOT USED NOT USED 2 CONNECTORS A9 2715 DISPLAY STORAGE BOARD ...
Страница 616: ...2715 Spectrum Analyzer Service Manual 9 140 ...
Страница 617: ...9 141 2715 Spectrum Analyzer Service Manual ADDRESS DECODING AND DATA BUFFERING A9 2715 DISPLAY STORAGE BOARD 3 ...
Страница 618: ...2715 Spectrum Analyzer Service Manual 9 142 ...
Страница 619: ...9 143 2715 Spectrum Analyzer Service Manual CONTROL REGISTERS A9 4 2715 DISPLAY STORAGE BOARD ...
Страница 620: ...2715 Spectrum Analyzer Service Manual 9 144 ...
Страница 621: ...9 145 2715 Spectrum Analyzer Service Manual 2715 5 A9 HORIZONTAL TRACKING A D CONTROL DISPLAY STORAGE BOARD ...
Страница 622: ...2715 Spectrum Analyzer Service Manual 9 146 ...
Страница 623: ...9 147 2715 Spectrum Analyzer Service Manual 2715 6 A9 VERTICAL DATA PROCESSING AND NVRAM DISPLAY STORAGE BOARD ...
Страница 624: ...2715 Spectrum Analyzer Service Manual 9 148 ...
Страница 625: ...9 149 2715 Spectrum Analyzer Service Manual 2715 READOUTS AND WAVEFORM DRAWINGS A9 DISPLAY STORAGE BOARD 7 ...
Страница 626: ...2715 Spectrum Analyzer Service Manual 9 150 ...
Страница 628: ...2715 Spectrum Analyzer Service Manual 9 152 ...
Страница 630: ...2715 Spectrum Analyzer Service Manual 9 154 ...
Страница 631: ...9 155 2715 Spectrum Analyzer Service Manual 10 HORIZONTAL OUTPUT DISPLAY STORAGE BOARD A9 2715 ...
Страница 632: ...2715 Spectrum Analyzer Service Manual 9 156 ...
Страница 633: ...9 157 2715 Spectrum Analyzer Service Manual 11 A9 VERTICAL OUTPUT DISPLAY STORAGE BOARD 2715 ...
Страница 634: ...2715 Spectrum Analyzer Service Manual 9 158 ...
Страница 635: ...9 159 2715 Spectrum Analyzer Service Manual 12 A9 MISCELLANEOUS DISPLAY STORAGE BOARD 2715 ...
Страница 637: ...9 161 2715 Spectrum Analyzer Service Manual 2715 SIGNAL INTERCONNECT A6 FRONT PANEL BOARD 0 ...
Страница 638: ...9 162 2715 Spectrum Analyzer Service Manual ...
Страница 639: ...9 163 2715 Spectrum Analyzer Service Manual SWITCH MATRIX A6 FRONT PANEL BOARD 2715 1 ...
Страница 640: ...9 164 2715 Spectrum Analyzer Service Manual ...
Страница 641: ...9 165 2715 Spectrum Analyzer Service Manual OUTPUT SHIFT REGISTERS AND POTS A6 FRONT PANEL BOARD 2715 2 ...
Страница 642: ...9 166 2715 Spectrum Analyzer Service Manual ...
Страница 643: ...9 167 2715 Spectrum Analyzer Service Manual GRAY CODE AND SERVICE REQUEST ACKNOWLEDGE A6 FRONT PANEL BOARD 2715 3 ...
Страница 644: ...9 168 2715 Spectrum Analyzer Service Manual ...
Страница 645: ...9 169 2715 Spectrum Analyzer Service Manual INPUT SHIFT REGISTERS AND LEDS A6 FRONT PANEL BOARD 2715 4 ...
Страница 648: ...2715 Spectrum Analyzer Service Manual 9 172 ...
Страница 649: ...2715 Spectrum Analyzer Service Manual 9 173 A5 2715 SIGNAL INTERCONNECT SWEEP BOARD 0 ...
Страница 650: ...9 174 2715 Spectrum Analyzer Service Manual ...
Страница 651: ...2715 Spectrum Analyzer Service Manual 9 175 VIDEO BUFFERING A5 2715 SWEEP BOARD 1 ...
Страница 652: ...9 176 2715 Spectrum Analyzer Service Manual ...
Страница 653: ...2715 Spectrum Analyzer Service Manual 9 177 2715 VIDEO TRIGGER A5 SWEEP BOARD 2 ...
Страница 654: ...9 178 2715 Spectrum Analyzer Service Manual ...
Страница 655: ...2715 Spectrum Analyzer Service Manual 9 179 2715 A5 SERIAL CONTROL REGISTER SWEEP BOARD 3 ...
Страница 656: ...9 180 2715 Spectrum Analyzer Service Manual ...
Страница 657: ...2715 Spectrum Analyzer Service Manual 9 181 2715 SWEEP RAMP GENERATOR SWEEP BOARD A5 4 ...
Страница 664: ...9 188 2715 Spectrum Analyzer Service Manual ...
Страница 665: ...2715 Spectrum Analyzer Service Manual 9 189 0 SIGNAL INTERCONNECT POWER SUPPLY BOARD A15A1 ...
Страница 666: ...9 190 2715 Spectrum Analyzer Service Manual ...
Страница 667: ...2715 Spectrum Analyzer Service Manual 9 191 2715 ...
Страница 668: ...9 192 2715 Spectrum Analyzer Service Manual ...
Страница 669: ...2715 Spectrum Analyzer Service Manual 9 193 2715 ...
Страница 670: ...9 194 2715 Spectrum Analyzer Service Manual ...
Страница 671: ...2715 Spectrum Analyzer Service Manual 9 195 2715 ...
Страница 672: ...9 196 2715 Spectrum Analyzer Service Manual ...
Страница 673: ...2715 Spectrum Analyzer Service Manual 9 197 2715 ...
Страница 674: ...9 198 2715 Spectrum Analyzer Service Manual ...
Страница 675: ...2715 Spectrum Analyzer Service Manual 9 199 2715 ...
Страница 676: ...9 200 2715 Spectrum Analyzer Service Manual ...
Страница 677: ...2715 Spectrum Analyzer Service Manual 9 201 2715 ...
Страница 678: ...9 202 2715 Spectrum Analyzer Service Manual ...
Страница 679: ...2715 Spectrum Analyzer Service Manual 9 203 2715 ...
Страница 680: ...9 204 2715 Spectrum Analyzer Service Manual ...
Страница 681: ...2715 Spectrum Analyzer Service Manual 9 205 2715 ...
Страница 682: ...9 206 2715 Spectrum Analyzer Service Manual ...