OPERATION
3-13
RPP
reset
*** REMOVE SIGNAL SOURCE ***
C0004
Fig. 3-5 RPP tripped
Pressing
[RPP Reset]
resets the RPP and returns the display to the menu in use when the reverse
power protection was tripped. If
[RPP Reset]
is pressed with the signal still applied, the RPP will
trip again.
Modulation
The carrier frequency can be modulated by conventional analog methods - frequency, amplitude,
phase (with pulse modulation as an option) - as well as the more complex modulation techniques -
PSK, QAM, FSK, GMSK, IQ.
Complex modulation modes
Digital
In the digital mode of operation the instrument can generate user-defined modulation formats from
either an internal data source or accept external data. Modulation can be applied in PSK, FSK,
GMSK and QAM formats with specified channel filter characteristics.
Advanced digital
In the advanced digital mode of operation the instrument has improved adjacent channel
performance for TETRA. The digital mode of operation is now limited to the TETRA modulation
format.
Vector
In the vector mode of operation the instrument provides IQ modulation of the carrier from an
external source by using the I IN/OUT and Q IN/OUT connectors on the front panel.
Analog modulation modes
Two independent inputs on the front panel — EXT MOD 1 INPUT, EXT MOD 2 INPUT —
allow external modulation signals to be summed with signals from the internal oscillator and a
second optional internal oscillator (if fitted). Thus up to four analog modulations may be available
at one time. These can be combined to give single, dual, composite and dual composite modes of
operation.