PART III: HT 81 HANDHELD TRANSMITTER III
1 Description 
The HT 81 handheld transmitter and matching microphone elements (optional) provide the same acoustic performance as the equivalent hardwire microphone versions. The microphone elements available for the HT 81 have been specifical- ly designed for vocal use.
The HT 81 operates in a subband up to 3 MHz wide within the 710 MHz to
860.9MHz UHF carrier frequency range. The HT 81 can be switched to a maxi- mum of 15 different carrier frequencies depending on local frequency allocations. The transmitter uses a dipole antenna integrated in the body.
The controls can be protected against accidental misadjustment collectively (2d) or individually with the supplied adjustable protective ring (2j).
2a | PWR: Switches the transmitter power ON ("I") and OFF ("0"). | 1.1 Controls | |
2b | Status LED: Indicates battery status and audio input overload. |
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| LED glowing dimly: batteries are OK. |
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| LED constantly lighting brightly: batteries will be dead in about 60 minutes. |
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| LED illuminating brightly: audio input is overloaded. |
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2c | MIC: Mutes the audio signal (position "0") while power and carrier frequency |
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| remain ON. |
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2d | Color Code: If you use the transmitter in a multichannel system you can |
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| remove the black plastic ring and replace it with a colored ring from the optio- |
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| nal Color Coding kit to identify each wireless channel by a different color. |
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2e | GAIN: This rotary pot allows you to match the microphone level to the trans- |
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| mitter’s audio section. |
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2f | Battery Compartment: Refer to Section 2 Setting Up. |
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2g | CHANNEL: This rotary switch selects the desired carrier frequency (depen- |
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| ding on local allocations) or switches between the carrier frequency and its |
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| alternative frequencies. |
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Prior to selecting frequencies, switch the transmitter OFF. | Important: | ||
2h | Carrier Frequency Table: A label listing the available frequencies is affixed |
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| to the battery compartment. |
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2i | Frequency Set Designation: The label inside the battery compartment also |
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| indicates the designation of the Frequency Set. |
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2j | Adjustable protective ring: Protects the controls from being misadjusted |
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| accidentally. |
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The interchangeable microphone elements (2k) D 880 WL1, D 3700 WL1, | 1.2 Interchangeable | ||
D 3800 WL1, C 5900 WL1, and C 535 WL1 are acoustically and mechanically | Microphone Elements | ||
identical to the equivalent hardwire versions. They feature the same transducer | (not supplied) | ||
capsules and mechanical construction. |
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Extremely high gain before feedback, optimum handling noise rejection, ultimate |
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protection from damage, and an integrated wind and pop screen are only the most impressive features of these microphones. For more details, refer to the respective AKG brochures.
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