4-20
4.5.3
Input B Amplifier Setup Procedure
4.5.3.1
Set R15 fully counterclockwise and R11 to its midposition. R11 and R15 are located
on the counter PCB as shown in Figure 4-15.
4.5.3.2
Select Frequency B as the measurement function, set Input B input impedance to 50
ohms and set the counter resolution to three digits. (Command Code FB BLI SRS3
BI)
If Option 11 is installed connect the 2251A internal reference output to the external
signal source 10 MHz Input. Configure the external signal source to accept the
10MHz reference from the 2251A. (Command String: FB BLI SRS3)
4.5.3.3
Connect the counter to the signal generator as shown in Figure 4-17.
Figure 4-17, Input B Amplifier Setup Configuration
4.5.3.4
Set the signal generator output to 100 MHz, 3.0 mV rms.
4.5.3.5
Adjust R11 to obtain a stable reading of 100 MHz ± 0.1 MHz. Verify that the
counters GATE LED is flashing.
4.5.3.6
Turn off the RF output of the signal generator.
4.5.3.7
Set the counter resolution to eight digits (Command code SRS8)
4.5.3.8
Increase the signal generator output level to 13 mV rms.
4.5.3.9
Adjust R15 slowly clockwise until the counter measurement result starts to become
unstable. Turn R15 slowly counterclockwise until the counter measurement result is
stable, value 100 MHz ± 1Hz.
4.5.3.10
Reduce the signal generator output level to 7 mV rms and verify that the GATE LED
stops flashing. If the LED continues to flash, repeat steps 5.5.4.8 to 5.5.4.10.
4.5.3.11
Disconnect the test equipment.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com