HP 8901B

3-4 Extending Operation
Extending
Operation
If You Need to Know:
Refer to:
Frequency
e How to make sure you are tuned to
the carrier.. ......................... Check Tuning (3-4)
e How to tune to the carrier when
other
RF signals or harmonics
are present.
..........................
Increasing Selectivity (3-5)
e How to retune to a new input
frequency ............................ Changing Frequency (3-5)
e How to tune to a noisy carrier ......
Noisy Carrier (3-5)
e How to track a drifty carrier.. ...... Drifty Carrier (3-6)
e How to measure modulation on a
carrier above 1300 MHz.. ........... Frequency Overrange (3-6)
e How to measure modulation on a
carrier below 150 kHz.. ............. Frequency Underrange (3-6)
Amplitude
e How to tune to a carrier whose
amplitude is very unstable ..........
Unstable Carrier (3-6)
Check Tuning
For most applications, the HP 8901Bs Auto Tuning mode enables the
instrument to automatically tune to the input signal. (Auto Tuning mode
is the right choice for measuring modulation on a single, stable camer.)
The
HP 89018 will inform you that it is having difficulty tuning by
placing dashes, error codes, or a very inaccurate reading in its display.
You can check what frequency the HI' 89018 is currently tuned to at any
time during the measurement by pressing the
Blue Shift key and then the
DISPLAY FREQ (fikHz) key. A way to ensure that the instrument is tuned to
the desired frequency is to manually tune it by keying in the input frequency
and then pressing the
MHz key. (If you are interested in details on how
the instrument operates in its Manual Tuning mode, refer to
Chapter 2.)