Philips Pm 5326 Bedienungsanleitung Seite 26

It is common practice to adequately fix the sliding DC voltage of AGC to a constant DC voltage from
a low-ohmic source. This can be achieved by an adjustable DC supply (e. g. PE 1535 or PE 15371,
if the controlling DC voltage of the t e s t object is related only to the chassis without being isolated.
In case of conductive hum-pickup, i t is recommended to use a dry battery or an accumulator and to
tap the voltage by means of a potentiometer connected in parallel to the battery. The output of such
a potentiometer circuit becomes more low-ohmic with moderate battery load, if the potentiometer
i s followed by a transistor ermitter-follower stage.
The connection point and the voltage level to be set are given in the checking and adjusting procedures
of the test object. Receivers with suppressed (delayed) control set-in point produce acceptable measur-
ing values, when working below the set-in point during measurement, so that the control is not
effective.
3.3.5. Type and connection of indicator
The following indicators can be used: multi-purpose instruments, calibrated signal tracers, selective
pV- or mV-meters, broadband voltmeters, oscilloscopes, wobble indicators and x/y recorders.
3.3.5.1. Connection to LF output
With supply of modulated signals, it is possible to connect indicators t o LF outputs. The loudspeakers
are replaced by resistors. Adjust the operating controls: volume to medium level, bass control
to maximum, treble control to maximum, bandwidth to narrow.
With several LF channels, connect the indicator to the bass channel.
) I @ - - - l
(eg P M 2 5 0 3 )
Fig. 3.3-8
r l
Indicator
Connecting indicator to LF output