HP 8901B

Model 8901B Operation
INPUT
ATTENUATOR IF AMP
-1 ~~~~~
Do not apply greater than 40 Vdc or greater than +15 dBm into the
rear-panel IF
OUTPUT connector.
ClRCU
IF BUFFER
-
DESCRIPTION
The rear-panel IF OUTPUT (a female BNC connector) provides a buffered output to enable monitoring
of the Modulation Analyzer’s
IF signal. The ac-coupled signal ranges from 150 kHz to 2.5 MHz and
normally varies in level from
-27 to -3 dBm (into 50 ohms). The level variation depends on the RF
input signal level, RF input attenuation setting, and the measurement selected.
The 3 dB bandwidth of the signal at IF OUTPUT is approximately 3 MHz when the instrument uses
the wide,
2.5 MHz low-pass filter and approximately 200 kHz when the instrument uses the wide, 455
kHz bandpass filter.
At any particular input level and front-panel setting, the flatness of the IF OUTPUT, as input frequency
varies, is typically within
k5%.
BLOCK DIAGRAM
TO OTHER
- MEASUREMENT
ITS
I-
L
IF Output Block Diagram
COMMENTS
Use the Modulation Analyzer as a Down Converter
The Modulation Analyzer can be used as a high-quality, automatically tuneable, down-converter. Use
the
IF OUTPUT as the down-converter’s output.
Adjacent Spurious Signals
Check for close-in spurious signals on the RF input by connecting a spectrum analyzer to IF OUTPUT.
When connecting instruments such as counters to the IF OUTPUT, check that they do not inject
spurious signals into the
IF path. Spurious signals in the Modulation Analyzer’s IF may generate
measurement error.
IF Output 3-103