Figure 8-2. Synthesizer Reference Oscillator Test Setup.
b. Modem Frequency Accuracy.
(1) Configure test equipment as shown in
(1) Insert the HP-5253B hetrodyne converter
(CV-2002/U) in the frequency counter. Turn on counter
(2) Turn on upconverter or downconverter and
and allow to warm up.
frequency counter and allow one hour for warm up.
(3) Measure frequency from 5 MHz output
jack on synthesizer. Test limit: 5 MHz + 6 MHz. If the
complete transmit and receive test loop, placing the
frequency error exceeds the test limit, replace the 5 MHz
desired modem upconverter, downconverter, PA, etc. on
oscillator module in the synthesizer. Refer the replaced
line. Turn on the on-line equipment. Set the PA in
module to depot for maintenance.
Do not attempt to adjust the
The available frequency counter is
not sufficiently accurate to make this