Operating instructions

LOCAL OPERATION
3-12
Low pass filters
The four low pass preset filters can each be set to any frequency within the range 250 Hz to
1.0 kHz and 3.0 kHz to 20.0 kHz.
The soft keys associated with the low pass filters are on the left of the setup page.
To set the required frequency, first press the soft key relevant to the low pass filter to be set. The
Freq: legend will become highlighted in reverse video. Use the Data Input keys to enter the
required frequency and then press the appropriate termination key. (Hz or kHz.)
This frequency will now be assigned to that low pass filter.
Band pass filters
The four band pass filters can each be customized to your requirements by selecting low pass and
high pass elements from the as required. The High pass element can be either 50 Hz or 300 Hz,
the low pass element can be any of the four preset low pass filters.
To select the required high pass element, first press the [LP / HP] soft key once or twice to move
the > indicator to the high pass elements on all four soft key settings boxes. Next, press the soft
key relevant to the band pass filter to be set. The 50Hz or 300Hz settings will toggle. Repeat this
to select the required filter element.
To select the required low pass element, first press the [LP / HP] soft key once or twice to move
the > indicator to the low pass elements on all four soft key settings boxes.
Next, press the soft key relevant to the band pass filter to be set. Each press will select one of the
LP1, LP2, LP3 and LP4 settings in sequence. Repeat until the required low pass filter element is
selected.
This setup will now be assigned to that band pass filter irrespective of from what test mode it is
accessed.
Atten Hold
The Attenuator Hold facility provides a ‘seamless’ range of RF Generator output that is not
subject to switched attenuator action. The available range is up to 20 dB, with a guaranteed range
of 10 dB.
Atten Hold Level
The value entered here sets the upper level of the ‘seamless’ range of RF Generator output. The
value must be within specified output range of the RF Generator. There is no account taken of any
RF Power External Attenuator settings entered in the Test Set, neither is the settable range
restricted when the ‘N’ type Connector is selected.
RF Power Ext Atten: dB
The value of any attenuator entered here is considered as part of the instrument and all power
measurements will be as from the input to the attenuator, not to the instrument input.
Similarly power output levels will be adjusted to take account of the external attenuator value
entered.
To enter a value of attenuation, which must be in dB, press the adjacent soft key, key in the
digits of the value using the data entry keys and then press the dB terminator key.
The entered value will be applicable to all RF connectors into and out of the monitor. When
changing test setups or test modes this must be taken into account to prevent erroneous
readings.
The indicator A is shown against any signal level which has been calculated to include the
external attenuator.