Kramer Electronics TP-1xl user manual Audio Control, Using a Microphone

11.7Audio Control

(707 only)

The balanced audio system (more details in section 5) is employed either when very low signals are transmitted over long distances (as is the case with high quality microphones in live shows), or in broadcast audio studios for highest quality signal creation. To produce a satisfactory audio level output, use an appropriate screwdriver to adjust the Audio Level trimmer located on the rear panel of the machine.

11.7.1Using a Microphone

A microphone is a device that converts sound waves to electrical pulses. High quality microphones usually generate a very low signal level. As a result, low noise/high fidelity pre-amplification is required to boost the output of a microphone before the signal reaches the main audio amplifier, where it is processed as a regular audio signal. When a microphone is used, perform the following steps:

1)Press the Cond.Mic push-button, located on the rear panel of the machine, in order to switch to “ Mic” position, in which the microphone is provided with an operation voltage coming from the machine.

2)Connect a condenser microphone to the Audio IN connector.

When a microphone is not used, the push-button should be released to the “ Audio in” position. In this case it is

recommended that Cond.Mic push-button should not be pressed!

11.8Typical Video/Stereo Audio Twisted Pair Link

It is sometimes necessary to transfer video and/or audio signals over long distances in order to distribute them to remotely located users. In many cases, coax wiring is impossible, impractical or costly, or only simple wiring is available. In such cases, and for distances of several hundred meters, twisted-pair video transmission is suitable. The system may be used effectively in schools, hospitals, airports, security applications and the like. Good quality video and audio signals can be obtained using twisted- pair wires, telephone or electric wires (not carrying signals or voltages) and any other practical setup made of two similar wires running in parallel.

Figure ￿￿ illustrates a typical application of the twisted pair devices described in this manual; an incoming color video signal from a source (VCR) is sent over long distance by the TP-11N, using a telephone wire or any other twisted pair wire. The TP-12N (Video Line Receiver) at the other end of the wire receives the signal and transfers it to an acceptor.

Figure ￿￿illustrates a case where an extension of range requires fine-tuning video and HF gain. The TP-6, Twisted Pair Line Amplifier is then installed on the line between the TP-11N and the TP-12N and is used to amplify and control the video signal traveling on it.

Perform the following steps (if necessary):

1)Connect the output from your video/audio source to a twisted-pair transmitter (TP-1xl, for video only, TP- 11N for video and stereo audio).

2)Connect the output of the twisted pair transmitter to a twisted-pair cable.

3)Tap off the line where necessary using a twisted pair line receiver (TP-2xl, TP-12N).

4)Connect a video/audio acceptor to the twisted-pair line receiver output.

5)Toggle all termination switches on the receivers except for the last to "Hi-Z" position. Toggle the last

receiver's termination switch to "Term" position (see section 11.2 for more details).

If the high frequency response must be adjusted, first use the controls of the transmitter (TP-1xl, TP-6 only), then fine-tune the receiver (TP-2xlonly) with its appropriate control, for optimal results.

Some useful tips:

￿￿A twisted pair line amplifier (TP-6 for example) may be inserted along the line, to extend the range, or enhance a specific area where reception is not sufficient.

￿￿Twisted pair transmission is affected by the quality of cables. Use high quality (low capacity) cables when possible.

￿

KRAMER ELECTRONICS LTD.

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