Service manual

1-32 June 21, 2004
GENERAL NP88 FLEX
Troubleshooting
Paging Sensitivity Check
Paging sensitivity is estimated by reducing the RF input signal level to the lowest
level that produces an alert tone on three successive trials.
1. Ensure the pager is turned off.
2. Enter the screen booth and turn the pager on.
3. Place the unit in the RTL-1005 Radiation Test Fixture.
4. Connect the test equipment as shown in Figure 1-30.
5. Determinethepagingcodes(address1,2,3,and4asapplicable)andthecarrier
frequency under test.
6. Set the test encoder for the address 1 code, FLEX, as applicable.
7. Set the FM signal generator to the carrier frequency of the pager, with a
relatively strong output level of about -60 dBm to ensure the unit pages.
8. ConnecttheoutputofthetestencodertotheFMgeneratorexternalmodulation
input and adjust the modulation deviation to the following values.
FLEX
±4.8 kHz
N
Paging sensitivity tests must be performed in a screen booth with a minimum of 80
dB attenuation. Pagers, especially FLEX pagers, lock onto the first identifiable
signal regardless of the source. If a pager under test locks onto a signal from a source
other than the signal generator it will not respond to the paging code from the
encoder. Ensure the pager is not turned on until it is secured within the booth.
Figure 1-30. Paging Sensitivity Check
N
Shield the pager from the signal generator to protect the pager from RF spray.
TEST
ENCODER
FM SIGNAL
GENERATOR
6dB
PAD
RADIATION
TEST FIXTURE
PAGER
UNDER
TEST
RF INPUT
ACPB-931512-O