Operating instructions

LOCAL OPERATION
3-25
SINAD
Selects SINAD as the measurement method.
The AF1 generator will be set to 1 kHz by this action, regardless of any previous setting.
The distortion bar chart ranges available are 0 to 18 dB and 0 to 50 dB. The SINAD level is
displayed as a digital readout above the bar chart. The TX TEST mode menu is recalled
automatically after pressing this key.
Dist’n
Selects distortion percentage as the measurement method.
The AF1 generator will be set to 1 kHz by this action, regardless of any previous setting.
The distortion bar chart ranges available are 0 to 10%, 0 to 30% and 0 to 100%. The distortion
percentage level is displayed as a digital readout above the bar chart. The TX TEST mode menu is
recalled automatically after pressing this key.
With all the required parameters set, power up the transmitter.
The power output of the transmitter is shown on the POWER LEVEL bar chart, with the power
level given in digital form above it.
The level of modulation is displayed on the modulation level bar chart, with the FM DEVN or the
AM DEPTH shown digitally. When the SSB demodulation function has been selected, no
modulation bar chart is displayed. The legend ‘SSB Trans’ and the selected sensitivity is shown.
The FREQ OFFSET will indicate the difference between the mean (measured) frequency of the
transmission and that entered as transmitter frequency.
More ( FM deviation pk/rms, Inst dBr, dBr Ref, Abs Meas
Press the [More] key. The right hand soft keys change, to allow selection of the FM deviation and
AM modulation measurement modes.
Press [More] to return to the previous menu or [Return] to display the main Tx TEST menu.
FM Dev Pk/rms
Toggles between measuring FM modulation with the RMS detector or with the peak detectors.
The measurement mode –
Pk or rms – appears to the left of the FM deviation bar chart.
Inst dBr
Pressing the [Inst dBr] soft key captures the current modulation level reading and enters it as the
dBr reference level.
dBr Ref
Pressing the [dBr Ref] soft key allows a modulation reference level to be set, so that the digital
modulation reading is shown as dBr levels relative to the reference. The bargraph readout and the
positive and negative readings continue to display the absolute values.
The reference level can be set using the Data input keys or captured from the current absolute
measurement by pressing the [Inst dBr] soft key.
Abs Meas
Pressing the [Abs Meas] soft key cancels the current dBr reverence level and restores the digital
modulation reading to absolute levels.