3-7 FREQUENCY
SYNTHESIS TESTS The following tests can be used to verify correct operation of the fre-
quency synthesis circuits. Frequency synthesis testing is divided into
two parts—coarse loop/YIG loop tests and fine loop tests.
TestSetup Connect the equipment, shown in Figure 3-2, as fol-
lows:
1. Connect the 682XXB/683XXB rear panel 10 MHz
REF OUT to the Frequency Counter 10 MHz Ex-
ternal Reference input. If the Frequency Counter
has an INT/EXT toggle switch, ensure the switch
is set to EXT.
2. Connect the 682XXB/683XXB RF OUTPUT to the
Frequency Counter RF Input as follows:
a. For measuring frequencies of 0.01 to 1.0 GHz,
connect to the Band 2 input (Connection A).
b. For measuring frequencies of 1.0 to 26.5 GHz,
connect to the Band 3 input (Connection A).
c. For measuring frequencies of 26.5 to 40.0 GHz,
connect to the Band 4 input via the Option 91
waveguide mixer (Connection B).
d. For measuring frequencies of 40.0 to 60.0 GHz,
connect to the Band 4 input via the Option 92
waveguide mixer (Connection B).
e. For measuring frequencies of 60.0 to 65.0 GHz,
connect to the Band 4 input via the Option 93
waveguide mixer (Connection B).

682XXB/683XXB MM 3-11

PERFORMANCE FREQUENCY
VERIFICATION SYNTHESIS TESTS

682XXB/683XXB FREQUENCY COUNTER

RF IN
Band 2
Input
Band 3
Input
Connection A
(
0.01 to 26.5 GHz
)
Connection B
(26.5 to 60 GHz)
10 MHz
EXT IN
Band 4
Input
Mixer
10 MHz
REF OUT
RF OUT
Figure 3-2. Equipment Setup for Frequency Synthesis Tests