Tektronix NetTek YBT250, Руководство пользователя

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Connecting a Signal
2- 26
YBT250 Field Transmitter & Interference Tester User Manual
The external reference signal requirements are:
H
The YBT250 locks on to signals that are within 1 ppm of an
acceptable frequency.
H
The external frequency reference input impedance is 50 ohms.
H
The signal level is between --15 dBm and +15 dBm.
Table 2--11 lists the acceptable external frequency reference signals.
Table 2- 11: Accepted external frequency reference signals
External reference
frequency
Transmitter/Frequency reference
1 to 15 MHz, in 1 MHz steps
4.8 MHz For Nortel BTS equipment.
10 MHz Standard frequency from WWV and other
high-accuracy references.
13 MHz For GSM systems.
15 MHz For Lucent W-CDMA.
1 MHz, 2 MHz, 5 MHz Along with 10 MHz, these are standard for
Rubidium and other high-accuracy References.
19.6608 MHz For Motorola, Qualcomm, and newer Nortel.
Used for CDMA only.
1.2288 MHz, 2.4576 MHz,
4.9152 MHz, 9.8304 MHz These are also multiples of the CDMA chip rate.
2.048 MHz For Ericsson BTS equipment with E1 reference
source
To connect an external frequency reference to the YBT250, connect
the frequency reference signal to the
FREQUENCY REFERENCE
INPUT
connector. The YBT250 automatically detects the reference
signal. When a valid external frequency reference is present, it is
used as the frequency (time base) reference.