17.
Connect a Load (28N50-2 or SM/PL) to
the Trans Test Port and verify that the
noise floor (isolation) is below –85 dB
(S120A) –80 dB (S251A) or –75 dB
(S235A and S250A).
18.
Press the
MARKER
key.
19.
Press the M1 soft key, then the EDIT
soft key.
20.
Using the keypad or the Up/Down Arrow
key, enter 1000.0 MHz (S120A and
S251A), or 1250 MHz (S235A) or
2000.0 MHz (S250A), then press
ENTER
.
21.
Press the BACK soft key, then the
MAIN soft key to return to the Main
Menu.
NOTE
For the following steps in the pro-
cedure, use only attenuators that
have Type N connectors. The use
of attenuators with other type con-
nectors and adapters will cause
measurement errors.
22.
Connect the 10 dB attenuator to the
Trans Test Port (refer to Figure 4) and
verify that the reading is:
q
S120A: 10 dB
±
2.25 dB @1000 MHz
q
S235A: 10 dB
±
2.25 dB @1250 MHz
q
S250A: 10 dB
±
2.25 dB @2000 MHz
q
S251A: 10 dB
±
2.25 dB @1000 MHz
23.
Connect the 10 dB and 30 dB attenuators
in series to the Trans Test Port and
verify that the reading is:
q
S120A: 40 dB
±
3.25 dB @1000 MHz
q
S235A: 40 dB
±
3.25 dB @1250 MHz
q
S250A: 40 dB
±
3.25 dB @2000 MHz
q
S251A: 40 dB
±
3.25 dB @1000 MHz
6.
RETURN LOSS VERIFICATION
The following test can be used to verify the accuracy
of return loss measurements. Measurement calibra-
tion of the Site Master is required for this test.
a.
Equipment Required:
·
20 dB offset, Anritsu SC5270
·
6 dB offset, Anritsu SC5237
·
Open/Short, Anritsu 22N50
·
50 Ohm Termination,
Anritsu 28N50-2 or SM/PL
b.
Procedure:
1.
Press and hold the
ESCAPE/CLEAR
key,
then press the
ON/OFF
key to turn on
the Site Master. (This sets the instru-
ment to the factory preset state.)
NOTE
Before continuing, allow a five
minute warm up for the internal
circuitry to stabilize
2.
Press the MODE soft key.
4
Site Master MM
Attenuator
Figure 4.
Test Setup
