Chapter 3 Operation; Power-Up Check; Test Tone; Sidetone Adjustment - Telex Audiocom US-2002 User Instructions

Power-Up Check

Plug in any PA-KP local power supplies that are being used, and also turn on any system power supplies that are being used.
When power is first applied to the US2002, it will perform a power-up reset, in which the front panel indicators will cycle
through all of their possible colors and then turn OFF. This verifies the general operation of the intercom station and indicators.
The US2002 also reads the settings of all DIP switches at this time and configures itself accordingly.

Test Tone

The US2002 can generate a test tone, which can be used to verify intercom channel operation after installation or to locate a
malfunction. This test tone is also used for the sidetone adjustment which follows.
Use the test tone as follows:
Simultaneously press the All Talk and PA keys to activate the test tone.
1.
Tap the Call key for the channel that you want to test (can be either US2002 channel or an ES4000A channel).
2.
Verify the test tone can be heard at all intercom stations on the channel. Replace any defective cables or intercom
3.
stations where the test tone is being lost.
Tap the same Call key to stop the test signal on that channel.
4.
Press any key except a Call key to turn OFF the test tone.
5.

Sidetone Adjustment

The US2002 uses full-duplex audio (the same as a conventional telephone line) in which the talk and listen audio are sent and
received on the same line. Thus, when you talk on a channel, you will also hear your own voice back in the speaker or
headphones. This is called sidetone. If you are using the US2002 with a microphone and speaker, sidetone could cause
unwanted feedback, since the microphone may pick up your returned voice audio and re-amplify it. This could also happen if
you are using a headset where the ear cushions do not completely cover the ears, although it is probably much less likely. In
either of the cases, you should minimize the amount of sidetone. On the other hand, if you are using headphone that
completely enclose the ears, a certain amount of your own voice level is desirable to overcome the muffled sensation when
talking.
CHAPTER 3
Operation
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