Lectrosonics Inc IFBT4VHF 사용자 설명서

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the Main window navigates to the Frequency window. 

The Frequency window displays the current operating 

frequency in MHz, as well as the standard Lectrosonics 

hex code. Also displayed is the UHF television channel to 

which the selected frequency belongs.
In XMIT mode, it is not possible to change the operating 

frequency.
In TUNE mode, the Up and Down buttons may be used 

to select a new frequency.
The UP and DOWN buttons navigate in 175 kHz incre-

ments. Holding the MENU butto+Up and MENU+Down 

move 2.8 MHz at a time. In any of the various group tun-

ing modes, the currently selected group identifier is dis-

played to the left of the hex code, and the Up and Down 

buttons navigate among the frequencies in the group. 

In factory group tuning modes A thru D, MENU+Up and 

MENU+Down jump to the highest and lowest frequen-

cies in the group. In user group tuning modes U and V, 

MENU+Up and MENU+Down permit access to frequen-

cies not currently in the group.
Pressing and holding the Up or Down button invokes an 

autorepeat function, for faster tuning.

Audio Input Gain Window

Pressing the MENU button once from 

the Frequency window navigates to 

the Audio Input Gain window. This 

window greatly resembles the Main 

window, with the exception that the current audio input 

gain setting is displayed in the upper left corner. The Up 

and Down buttons may be used to alter the setting while 

reading the realtime audio meter to determine what 

setting works best.
The gain range is -18 dB to +24 dB with 0 dB nominal 

center. The reference for this control can be changed with 

the rear panel MODE switches. See the 

Operation section for more information on the MODE 

switches.

Setup Window

Pressing the MENU button once 

from the Audio Input Gain window 

navigates to the Setup window. This 

window provides access to a menu 

for various setup screens.
Initially the active menu item is EXIT. Pressing the Up 

and Down keys permits navigation to the menu items: 

COMPAT and ROLLOFF.
Pressing the MENU button selects the current menu 

item. Selecting EXIT navigates back to the Main window. 

Selecting any other item navigates to the associated setup 

screen.

ROLLOFF Setup Screen

The ROLLOFF setup screen controls 

the low frequency audio response of 

the IFBT4 by moving the 3 dB corner 

IFBT4 Front Panel

OFF/TUNE/XMIT Switch

OFF  Turns the unit off.
TUNE  Allows all functions of the transmitter to be set 

up, without transmitting. The operating frequen-

cy may only be selected in this mode.

XMIT  Normal operating position. The operating 

frequency may not be changed in this mode, 

though other settings may be changed, so long 

as the unit isn’t “Locked.”

Power Up Sequence

When power is first turned on, the front panel LCD 

display steps through the following sequence.
1.   Displays Model and the firmware verson 

(e.g. IFBT4VHF and V1.0).

2.   Displays the current compatibility mode setting  

(e.g. COMPAT  IFB).

3.   Displays the Main Window.

Main Window

The Main window is dominated by an 

audio level meter, which displays the 

current audio modulation level in real 

time. In TUNE mode, a blinking 

capital “T” is displayed in the lower left corner to 

remind the user that the unit is not yet transmitting. In 

XMIT mode, the blinking “T” is replaced by an antenna 

icon.
Audio limiting is indicated when the audio bargraph 

extends all the way to the right and widens somewhat. 

Clipping is indicated when the zero in the lower right 

corner changes to a capital “C”.
The Up and Down buttons are disabled in this Window.

Frequency Window

Pressing the MENU button once from 

Front Panel Controls and Functions