Panasonic VP-7721A Manual

4u-Fig. 4-6 shows the oscillator output circuit. The common side^ | j 0£ the OSC OUTPUT connector (outer metal shell of theBNCconnector) is floated from the chassis ( 7)7-) - Thisfloating scheme is not primarily for floating voltage but forpreventing a ground loop which may be formed by connecting thisinstrument to the device under measurement. The common sideis usually connected to the chassis ground directly at anappropriate point in the measurement setup. For floatingrequirement, however, up to 5 volts can be applied withoutaffecting the perfomance.The maximum allowable floating voltage without damage is 10volts (peak) as noted on the front panel (Fig. 4-5).If a non-floating input equipment is connected to this connec¬tor, the common side ( ) is grounded directly. This is anormal state for audio frequency measurements.The metal terminal marked with (see Fig. 4 5) is used toconnect a separate wire which links the chassis or to connectthe braid of a shielded wire to provide common ground.The output of the oscillator is an unbalanced type due to thecircuit configuration shown in Fig.. 4-6.Be careful not to apply an external voltage to the OSC OUTPUTconnector accidentally.Applying 12 volts or more across "A" in Fig. 4-6 will deteri-orate internal components.The maximum permissible voltage between the center conductorof the OSC OUTPUT connector and the chassis is also 10 volts(peak).•CMa' o•x; 4-22