428 Chapter9
IF Section
Introduction
Introduction
The IF section contains the A4 log amplifier/cal oscillator and the A5 IF
assemblies. Figure 9-2 on page 431 illustrates the location of the A4
and A5 test connectors. Figure 9-7 on page 436 illustrates the level and
paths through the IF section.
Troubleshooting Using the Diagnostic Software ........... page 430
Troubleshooting the Cal Oscillator on A4 .................... page 431
Using Diagnostic Software
Troubleshooting A5 Using Diagnostic Software .......... page 435
Automatic IF Adjustment ............................................... page 437
Parameters Adjusted .................................................... page 438
Requirements ................................................................ page 439
Performance Test Failures .............................................. page 441
IF Gain Uncertainty Performance Test ....................... page 441
Scale Fidelity Performance Test .................................. page 442
Resolution Bandwidths Performance Tests ................. page 442
Log Amplifier (P/O A4 Assembly) ................................... page 443
Log Amplifier ................................................................. page 443
Linear Amplifiers .......................................................... page 444
Video Offset ................................................................... page 447
Video Output ................................................................. page 447
Frequency Counter Prescaler/Conditioner .................. page 448
AM/FM Demodulator .................................................... page 448
4.8 kHz IF Filters .......................................................... page 449
10.7 MHz IF Filters ....................................................... page 450
4.8 kHz and 10.7 MHz IF Filters ................................. page 450
10.6952 MHz VCXO ...................................................... page 451
Input Switch .................................................................. page 451
LO Switch ...................................................................... page 452
Synchronous Detector ................................................... page 452
Limiter ........................................................................... page 453
Isolation Amplifier ........................................................ page 453
Detector/Mixer ............................................................... page 453
Log Offset/Gain Compensation .................................... page 453
Log Offset Compensation .............................................. page 453
Log Gain Compensation ................................................ page 454
Video MUX .................................................................... page 454
A5 IF Assembly ............................................................... page 455
IF Signature .................................................................. page 456
Common IF Signature Problems .................................. page 462
1 MHz Resolution Bandwidth Problems ...................... page 465
30 kHz Resolution Bandwidth Problems .................... page 466
3 kHz and 10 kHz Resolution Bandwidth Problems ... page 467
Step Gains ..................................................................... page 468
Cal Oscillator (P/O A4 Assembly) .................................. page 469
To Next Page
Loading...
Need help?
General
