Lectrosonics Inc DHU 사용자 설명서

3

General Technical Description

Introduction

The DHu handheld transmitter delivers superb audio 

quality and extended operating range in a pure digital 

architecture. Interchangeable microphone capsules 

expand the versatility to suit a wide variety of applica-

tions and personal preferences. The superb audio per-

formance and highly reliable RF transmission makes it 

ideally suited for high end stage and studio production.

Frequency Selection

The transmitter tunes continuously from 470.100 to 

607.975 MHz in 25 kHz steps, making it easy to find 

clear operating frequencies. Operating frequency is 

normally selected using a receiver or analyzer to as-

sess signals in the local environment to avoid interfer-

ence. Once an interference-free frequency is identified, 

the transmitter frequency is set to match the receiver.

Input Gain Range and Limiter

45 dB range of input gain adjustment allows gain 

settings to accurately match the user’s voice and the 

varying sensitivity of different microphone capsules. A 

DSP-controlled analog audio limiter is employed be-

fore the A-D converter. The limiter has a range of more 

than 30 dB for excellent overload protection. A dual re-

lease envelope makes the limiter acoustically transpar-

ent while maintaining low distortion. It can be thought 

of as two limiters in series, a fast attack and release 

limiter followed by a slow attack and release limiter. 

The limiter recovers quickly from brief transients, with 

no audible side effects, and also recovers slowly from 

sustained high levels to keep audio distortion low while 

preserving short term dynamics.

Long Battery Life

Switching power supplies throughout the design al-

low over 5 hours of operation using two alkaline AA 

batteries. The battery compartment and contacts are 

designed to prevent “rattle” as the unit is handled.

Menu-Driven Control

A high-resolution LCD and control panel with mem-

brane switches provide access to the menu-driven 

setup. Transmitter RF power, low frequency rolloff, 

frequency selection, backlight timeout settings and 

programmable switch functions are easily accessed.

Antenna

A newly designed helical antenna allows the transmit-

ter to be held in any position, since the user’s hands 

have little or no effect on the RF output power.

Microphone Capsules

The transmitter is available from Lectrosonics with the 

HHC cardioid condenser capsule. Capsules from sev-

eral other manufacturers with a 1.25” x 28 thread pitch 

and three contact rings are also available for use with 

the transmitter. Condenser or dynamic microphone 

heads can be used with the transmitter, depending on 

the user’s preference or the application.

Side Button Functions

A programmable switch on the side of the housing can 

be configured as a mute/cough switch, a power switch, 

or be disabled.

USB Port for Firmware Updates

Firmware updates are enabled by simply downloading 

a file and utility program from the Lectrosonics web 

site, connecting the transmitter to a computer via the 

USB port and running the program.