274 Chapter5
Troubleshooting the IF Section
Troubleshooting the A15 Motherboard Assembly
HSWP High Sweep Provides control for the analyzer display sweep and
retrace. A TTL high starts a sweep and a TTL low
initiates a retrace. This is an open-collector signal.
It should never be driven high.
IFA1 IF Attenuation 1 Control line for 1dB step attenuator on the A12
Amplitude Control assembly.
IFA2 IF Attenuation 2 Control line for the 2 dB step attenuator on the A12
Amplitude Control assembly.
IFA3 IF Attenuation 3 Control line for the 4 dB step attenuator on the A12
Amplitude Control assembly.
IFA4 IF Attenuation 4 Control line for the 8 dB step attenuator on the A12
Amplitude Control assembly.
IFA5 IF Attenuation 5 Control line for the 16 dB step attenuator on the
A12 Amplitude Control assembly.
IFG1 IF Gain 1 Control line for the 10 dB step gain on the A12
Amplitude Control assembly.
IFG2 IF Gain 2 Control line for the first 20 dB step gain on the A12
Amplitude Control assembly.
IFG3 IF Gain 3 Control line for the second 20 dB step gain on the
A12 Amplitude Control assembly.
IFG4 IF Gain 4 Temperature-compensated control line for the 10 dB
linear gain on the A14 Log Amplifier assembly.
IFG5 IF Gain 5 Temperature-compensated control line for the 10 dB
linear gain on the A14 Log Amplifier assembly.
IFG6 IF Gain 6 Temperature-compensated control line for the 20 dB
linear gain on the A14 Log Amplifier assembly.
INTERBUS Interbus A communication line between the four slots in the
card cage. It coordinates functions between options
when more than one option is installed in the card
cage.
IOB0-IOB15 Input/Output Bus
0- Input/Output
Bus 15
Input/Output (IO) data lines used between the A16
Processor/Video assembly and related assemblies.
LBIO Low Bottom-box
Input/Output
Strobe line for Input/Output (IO) data transfers.
LINE_TRIG Line Trigger Provides a TTL signal at the power-line frequency
rate. It enables the line-trigger mode on the A16
Processor/Video assembly.
Table 5-6 A15 Motherboard Mnemonic Descriptions (Continued)
Mnemonic Full Name Description