The voltage amplifier is turned "on" by turning the battery switch to the "ON" position. When
this is done the filaments of the voltage amplifier and the indicator lamp to the left of the test
meter should light.
The power amplifier is switched "on" by turning the power amplifier switch to the "ON"
position. The monitoring speaker should be plugged into the monitoring jack on the power
199. Troubles on the PG-4 Equipment. -The troubles which may be experienced with the PG-4
equipments are similar to those discussed for the PG-3 equipments in section 193. See also
Since there is but one voltage amplifier and one power amplifier included in this equipment it is
very important that the amplifiers be kept in good condition. It is advisable to keep a supply of
tubes, which have been previously tested, ready
for emergency use. Testing the equipment before the show starts may forestall trouble which might
otherwise occur during the show.