438 Chapter9
IF Section
Automatic IF Adjustment
Parameters Adjusted
The following IF parameters are adjusted in the sequence listed:
1. Amplitude
a. Video Offsets: analog (using log amplifier video offset DAC) and
digital (applying stored constant to all readings)
1. Linear Scale Offset
2. Log Scale Offset
1. Wideband and Narrowband modes
2. 0 to 60 dB range in 10 dB steps
3. 10 dB/division and 2 dB/division (log expand) modes
b. Step Gains (A5 IF Assembly)
1. First Step Gain for 16 different DAC settings
2. Second Step Gain for 16 different DAC settings
3. Third Step Gain for 0, 15, and 30 dB attenuation relative to
maximum gain
4. Fine Attenuator for 32 evenly-spaced DAC settings
c. Log Amplifier Slopes and Fidelity
1. Wideband (RES BW 300 kHz through 2 MHz) and
Narrowband modes (RES BW 300 Hz through 100 kHz)
2. 10 dB/division and 2 dB/division (log expand) modes
d. Linear Scale Gains - On the log amplifier assembly (P/O A4)
e. Peak Detector Offsets (both Positive and Negative Peak Detectors
with respect to normal sample path used by Auto IF Adjust)
2. LC Bandwidths
a. 300 kHz resolution bandwidth center frequency, bandwidth, and
gain
b. 1 MHz resolution bandwidth center frequency, bandwidth, and
gain
c. 2 MHz resolution bandwidth gain
d. 100 kHz resolution bandwidth center frequency, bandwidth, and
gain
e. 30 kHz resolution bandwidth center frequency, bandwidth, and
gain
To Next Page
Loading...
Need help?
General
