The LEVEL TEST SET ET 91 is a hand held battery operated, multifunction measuring instrument, intended for the test of Carrier Frequency Systems up to 600 channel capacity, Power Line Carrier, Audio Tone, and FSK Communications Systems.
In selective receiving mode four special bandwidths are provided for the measurement of noise, carrier leak, crosstalk and non-linear distortion.
• Comfortable Frequency Setting ModesNo frequency calculation is required!
Test instructions of FDM systems often specify the test frequency in format: Carrier ± Channel Frequency. In compliance with the mentioned format ET 91 provides the separate setting of carrier and audio frequencies and so:
• Comfortable Frequency Tracking Modes
The test procedure of FDM equipment usually requires different generator and level meter frequency settings.
Feeding audio frequency test signal to the input of the tested channel on the following frequencies:
1000, 1200, 1400, 1600, etc Hz
Selective level measurement at a designated test point of the tested equipment on the following frequencies:
Carrier + 1000, 1200, 1400, 1600, etc Hz or
Carrier - 1000, 1200, 1400, 1600, etc Hz
Using up the advantageous feature of ET 91 that the generator and the level meter are in the same instrument extremely comfortable tracking modes are provided. In these modes the selective level meter is controlled by the generator according to the above mentioned rules.
No frequency calculation is required !
Only one frequency setting is required !