Sweep Mode Operating Instructions 4-34.2.2 Level The Level function has 5 sub-menus, each one with several options..Pressing the Display button it is possible to set two parameters: thevisualized Dynamic range (chosen between 80, 100 and 120dB) and theReference Level, that can be increased or reduced by steps of 5dB withinthe range +80 dBμV to 135 dBμV (-25 to +30 dBm).The Input button opens a submenu which is dedicated to the setting of theinput attenuator and to switch on-off the built-in preamplifier.The PMM 9010 receiver takes automatically into account the settings of allthe Input parameters and always displays the correct value of the level. TheUser is not required to make any correction to the readings.4.2.2.1 Input:Attenuators andpreamplifierBeing entered in the Input submenu, to increase or decrease the attenuationat the input, press Att + or Att -, and for each touch the attenuation isincreased or decreased of 5 dB (preset value). Depressing either one ofthese keys force the receiver in manual attenuation.When the input attenuation is 0dB (condition that can be achieved only if theMinimum Attenuation is set to 0 dB as well), the yellow led to the left of theinput BNC connector is ON and indicates a warning status.The Min Att button acts as a toggle switch: it selects or deselects theminimum attenuation of 10 dB. When the minimum attenuation is selected,the attenuator – doesn’t matter if in automatic or in manual condition -cannot be lowered under 10 dB.Unless specifically required by the test conditions, do not remove theminimum attenuation of 10 dB.With the Preamp key it is possible to insert or exclude the built-in low noisepreamplification of 20 dB.The internal 20 dB preamplifier can be used when very weak signals have tobe investigated. As already mentioned, with the preamplifier ON the receivertakes automatically care of the 20 dB gain when measuring the signals.The Att Auto button is used to switch from the two conditions of manual orautomatic attenuation setting.Please note that the switching of the attenuators is relatively noisy and youcan perceive it distinctly with a “click” for each switch operation.In case an OVERLOAD indication occurs it is necessary to add an externalattenuator to carry on the measurement without overpassing the declaredlimit for continuous power or spectral density.Using 0 dB attenuation PMM 9010 has no input protection.This is a potentially dangerous condition for the input stage of thereceiver.Use 0 dB attenuation only if you are very sure that your input signal isless than 0.5 Vpp (or 106 dBμV).Before to apply an unknown signal to PMM 9010 receiver, use anoscilloscope or a wide band RF voltmeter to measure it. In any case setMin. ATT at 10 dB and select the maximum available attenuation withpreamplifier OFF.If needed, add an external coaxial attenuator on the input signal line.
