OPERATION
3-12
Detailed operation
Carrier frequency
The carrier frequency is selected from the
Sig Gen
menu by pressing
[Carrier Freq.]
, unless it is
already highlighted as in the default display.
Enter the required value via the numerical key pad. The value can then be incremented or
decremented using the control knob and its associated keys, [KNOB UP-DN], [
×
10] and [
÷
10].
If a value outside the specified range is requested, the message:
ERROR 51: Carrier Outside Limits
is displayed on the screen when the terminator key is pressed, and the instrument is automatically
set to the end of the range.
Carrier ON/OFF
The carrier may be switched
ON
or
OFF
at any time via the [CARR ON-OFF] key. This
effectively switches the output ON and OFF, retaining the 50
Ω
output impedance.
Output level
The output level is selected at the
Sig Gen
menu by pressing
[RF Level]
and entering the required
value on the numerical key pad. The value can then be incremented or decremented using the
control knob and its associated keys, [KNOB UP-DN], [
×10] [÷10].
If a value outside the
specified range is requested the message:
ERROR 52: RF Level Outside Limits
or
ERROR 17: RF Level limited by AM
is displayed and the instrument is automatically set to the end of the range.
The knob resolution is fixed at 0.1 dB.
Choice of units
Units may be
μ
V, mV, V or dB. Conversion between dB and the voltage units is carried out by
pressing the appropriate units key, i.e. to change dBm to a voltage unit, press any
voltage key for
the correct conversion. The choice of Volts EMF, Volts PD, and the dB reference is made by using
the
[RF Level Units]
utility, see Page 3-77, 'RF level units'.
Reverse power protection
Accidental application of power to the RF OUTPUT socket trips the reverse power protection
circuit (RPP) and a flashing message appears on the display, see Fig. 3-5.