Chapter 7
367
ADC/Interface Section
Flatness Control (RF Gain DACs)
Flatness Control (RF Gain DACs)
Refer to function block M of A3 Interface Assembly Schematic
Diagram (sheet 4 of 6) in the
HP 8560 E-Series Spectrum Analyzer
Component Level Information
.
RF Gain DACs control the A15 assembly flatness compensation
amplifiers. The RF Gain DACs are arranged so that the output of one
DAC is the voltage reference for the other DAC. This results in an RF
GAIN voltage which is exponentially proportional to the DAC settings.
Each DAC is set to the same value. The A15 RF assembly converts the
RF GAIN signal to a current for driving the PIN diode attenuators in
the Flatness Compensation Amplifiers. The exponentially-varying
voltage compensates for the nonlinear resistance-versus-current
characteristic of the PIN diodes.
1. Place the WR PROT/WR ENA jumper on the A2 controller assembly
in the WR ENA position.
2. Press
CAL
,
MORE 1 OF 2
,
SERVICE CAL DATA
,
FLATNESS
, and
FLATNESS DATA
. Press
NEXT BAND
until "FLATNESS BAND # 0" is
displayed.
3. Press the
▲
key until "DATA @ 300 MHz" is displayed. Note the
number directly underneath "DATA @ 300 MHz"; this is the RF Gain
DAC value.
4. Connect a positive DVM lead to A3J400 pin 13 and the negative
DVM lead to A3TP4.
5. Check that the DVM reading increases from near 0 Vdc to between
−
1.3 and
−
1.9 Vdc as the RF Gain DAC setting is increased from 0 to
4095.
6. If the DVM readings are incorrect, press
PRESET
,
SGL SWP
,
CAL
,
MORE 1 OF 2
,
SERVICE CAL DATA
,
FLATNESS
, and
FLATNESS
DATA
. Press
NEXT BAND
until "FLATNESS BAND # 0" is displayed.
Press the
▲
key until "DATA @ 300 MHz" is displayed. Proceed as
follows:
a. Check the +10 V reference.
b. Check for narrow, low-going pulses at A3U417 pin 13 (LWRCLK).
c. While rotating the front panel knob, check for narrow, low-going
pulses at A3U417 pin 1 (LDAC1) and pin 14 (LDACU1).
d. While rotating the front panel knob, check for narrow, low-going
pulses at U417 pin 16 (L_IA0) and pin 15 (IA4).
7. If the LWRCLK, LDAC1, or LDACU1 is incorrect, refer to the
Interface Strobe Select block in this chapter.
Summary of Contents for 8560E
Page 17: ...16 Contents ...
Page 24: ...23 1 General Information ...
Page 49: ...48 Chapter1 General Information Sales and Service Offices ...
Page 50: ...49 2 Adjustment Procedures ...
Page 132: ...131 2a Adjustment Procedures HP 3335A Source not Available ...
Page 146: ...145 3 Assembly Replacement ...
Page 224: ...223 4 Replaceable Parts ...
Page 251: ...250 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 253: ...252 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 255: ...254 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 257: ...256 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 259: ...258 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 261: ...260 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 263: ...262 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 265: ...264 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 267: ...266 Chapter4 Replaceable Parts Firmware Dependent Part Numbers ...
Page 268: ...267 5 Major Assembly and Cable Locations ...
Page 279: ...278 Chapter5 Major Assembly and Cable Locations Introduction Figure 5 9 Front End ...
Page 281: ...280 Chapter5 Major Assembly and Cable Locations Introduction ...
Page 282: ...281 6 General Troubleshooting ...
Page 285: ...284 Chapter6 General Troubleshooting Introduction Figure 6 1 Assembly Test Points ...
Page 286: ...Chapter 6 285 General Troubleshooting Introduction Figure 6 2 Ribbon Cable Connections 1 of 3 ...
Page 287: ...286 Chapter6 General Troubleshooting Introduction Figure 6 3 Ribbon Cable Connections 2 of 3 ...
Page 290: ...Chapter 6 289 General Troubleshooting Introduction Figure 6 5 Service Cal Data Menu ...
Page 331: ...330 Chapter6 General Troubleshooting Block Diagram Description Figure 6 6 Functional Sections ...
Page 343: ...342 Chapter6 General Troubleshooting Block Diagram Description ...
Page 345: ...344 Chapter6 General Troubleshooting Block Diagram Description ...
Page 347: ...346 Chapter6 General Troubleshooting Block Diagram Description ...
Page 349: ...348 Chapter6 General Troubleshooting Block Diagram Description ...
Page 351: ...350 Chapter6 General Troubleshooting Block Diagram Description ...
Page 353: ...352 Chapter6 General Troubleshooting Block Diagram Description ...
Page 354: ...353 7 ADC Interface Section ...
Page 406: ...405 8 IF Section ...
Page 436: ...Chapter 8 435 IF Section A5 IF Assembly Figure 8 3 IF Adjust Signature ...
Page 437: ...436 Chapter8 IF Section A5 IF Assembly Figure 8 4 Detailed IF Adjust Signature 1 ...
Page 438: ...Chapter 8 437 IF Section A5 IF Assembly Figure 8 5 Detailed IF Adjust Signature 2 ...
Page 439: ...438 Chapter8 IF Section A5 IF Assembly Figure 8 6 Detailed IF Adjust Signature 3 ...
Page 440: ...Chapter 8 439 IF Section A5 IF Assembly Figure 8 7 Detailed IF Adjust Signature 4 ...
Page 441: ...440 Chapter8 IF Section A5 IF Assembly Figure 8 8 Detailed IF Adjust Signature 5 ...
Page 443: ...442 Chapter8 IF Section A5 IF Assembly Figure 8 9 Noisy Signature ...
Page 444: ...Chapter 8 443 IF Section A5 IF Assembly Figure 8 10 Noise with Correct Shape ...
Page 445: ...444 Chapter8 IF Section A5 IF Assembly Figure 8 11 Region B Amplitude Variation ...
Page 447: ...446 Chapter8 IF Section A5 IF Assembly Figure 8 13 Faulty Crystal Short ...
Page 463: ...462 Chapter8 IF Section Cal Oscillator Assembly P O A4 ...
Page 465: ...464 Chapter8 IF Section Cal Oscillator Assembly P O A4 ...
Page 467: ...466 Chapter8 IF Section Cal Oscillator Assembly P O A4 ...
Page 469: ...468 Chapter8 IF Section Cal Oscillator Assembly P O A4 ...
Page 470: ...469 9 Controller Section ...
Page 486: ...Chapter 9 485 Controller Section Display Problems 8560E Figure 9 10 Delta Y Waveform ...
Page 503: ...502 Chapter9 Controller Section Keyboard Problems ...
Page 505: ...504 Chapter9 Controller Section Keyboard Problems ...
Page 506: ...505 10 Synthesizer Section ...
Page 577: ...576 Chapter10 Synthesizer Section A21 OCXO ...
Page 579: ...578 Chapter10 Synthesizer Section A21 OCXO ...
Page 581: ...580 Chapter10 Synthesizer Section A21 OCXO ...
Page 582: ...581 11 RF Section ...
Page 598: ...Chapter 11 597 RF Section A14 Frequency Control Assembly Figure 11 2 A7 LODA Drive ...
Page 617: ...616 Chapter11 RF Section A10 Tracking Generator Option 002 ...
Page 618: ...617 12 Display Power Supply Section ...
Page 651: ...650 Chapter12 Display Power Supply Section A6 Power Supply Assembly ...
Page 653: ...652 Chapter12 Display Power Supply Section A6 Power Supply Assembly ...
Page 654: ...653 13 Component Level Information Packets ...
Page 660: ...Chapter 13 659 Component Level Information Packets Introduction ...