Lectrosonics IFBT4 User Manual

IFBT4

Frequency Agile IFB Transmitter

• Digital Hybrid Wireless™ technology

• 256 UHF frequencies in 100kHz steps

• Microprocessor controlled operation

• 250 mW power output for long range use

• Pilot tone squelch control

• Multi-use XLR input jack

• Built-in microphone preamp

• DIP switch programmable intercom input

TECHNICAL DATA

• Tx mute for frequency scrolling

• Multi-function LCD display

• Rugged machined aluminum construction

The Lectrosonics IFBT4 transmitter was designed for
use in broadcast, motion picture, theater, and stage
applications where extended operating range and high
quality audio are essential. The transmitter can be used
as a stand-alone device or patched directly into popular
intercom systems.

Lectrosonics Digital Hybrid Wireless™ systems over­come channel noise in a dramatically new way, digitally
encoding the audio in the transmitter and decoding it in
the receiver, yet still sending the encoded information via
an analog FM wireless link. This proprietary algorithm is
not a digital implementation of an analog compandor but
a technique that can be accomplished only in the digital
domain, even though the inputs and outputs are analog.

Because it uses an analog FM link, Digital Hybrid Wire­less™ enjoys all the benefits of conventional FM wire­less systems, such as excellent range, efficient use of
RF spectrum, and resistance to interference. However,
unlike conventional FM systems, it does away with the
analog compandor and its artifacts.

256 UHF frequencies in 100kHz steps provide excep­tional flexibility in coordinating frequencies in multi-chan­nel wireless systems and avoiding interference from
external RF signal sources and noise.

Microprocessor control provides user-friendly operation
and eliminates transients at turn-on and turn-off. The
transmitter output is muted in the TUNE mode to avoid
generating interference in other wireless systems while
scrolling up and down to change frequencies. In the
XMIT mod e, the output is turned on and the frequency
cannot be changed.

The transmitter delivers 250 mW of output power which,
when used with an efficient antenna, provides excep­tional operating range with the R1A belt-pack receiver.
Indoors, the signal will penetrate various surfaces and
reflect from others efficiently to extend operating range
and reduce the need for critical antenna positioning.

A supersonic pilot tone signal controls the audio squelch
on the R1A receiver to eliminate noise when the trans­mitter is turned off and it prevents the receiver from
locking onto false signals. The pilot tone also eliminates
noise in the receiver at turn-on and turn-off.

The LCD display is backlit for use in dimly lit conditions
and is also highly visible in direct sunlight.

DIP switch settings on the rear panel provide direct com­patibility with RTS and Clear Com intercom systems. A
preamp stage is also included in the input stage to allow
direct connection to dynamic microphones in “stand­alone” applications. Direct output at studio line level can
also be fed directly into the transmitter.

The transmitter housing is rugged, machined aluminum
with an electrostatic powder coating and an anodized fin­ish. The unit is powered by 6 to 18 Volts DC via a locking
connector. The supplied whip antenna is a detachable,
locking 1/4 wavelength flexible, galvanized steel cable
that connects to a 50 Ohm BNC connector on the rear
panel.

The rear panel provides the audio input and programming
DIP switches for intercom and audio input type along with
power and antenna input jacks.

Rio Rancho, NM, USA
www.lectrosonics.com

581 Laser Road NE • Rio Rancho, NM 87124 USA • www.lectrosonics.com
[phone] • [phone] • fax [phone] • [e-mail]

IFBT4 Transmitter Block Diagram

Specifications

Operating Frequencies (MHz):

Block 21 537.600 - 563.100

Block 22 563.200 - 588.700

Block 23 588.800 - 607.900

614.100 - 614.300

Block 24 614.400 - 639.900

Block 25 640.000 - 665.500

Frequencies (Channels per block): 256

Channel Spacing: 100 kHz (0.1 MHz)

RF Power Output: 250 mW

Spurious & Harmonic Suppression: 37 dBc above 1 GHz

Frequency Stability: ±.001% (10 ppm) @ 25° C

Temperature Stability: ±.001% (10 ppm) from -30° C to +50° C

Channel Selection: Momentary pushbutton switches,
TUNE Up and Down

Compatibility Modes (6) Digital Hybrid Wireless(tm) (400 Series),
100 Series, 200 Series, Mode 3, Mode 6, and IFB

Pilot Tone: 29.997 kHz IFB & 100 MODE, 32.765kHz
200 MODE, 400 MODE step selected

Modulation: FM, ±20 kHz deviation IFB & 100 MODE, ±75kHz
200 & 400 MODE

Audio Frequency Response: 100 Hz to 8 kHz, ±1 dB, IFB MODE system response
(see Rolloff)

30Hz to 20kHz ±1dB , 200 & 400 MODE system
response (see Rolloff)

Rolloff: Low frequency audio rolloff is Menu selectable for
3 dB down at 35 Hz or 50 Hz.

Signal to Noise Ratio: 90 dB typical (“A” weighted)

Block 26 665.600 - 691.100

Block 27 691.200 - 716.700

Block 28 716.800 - 742.300

Block 29 742.400 - 767.900

Block 944 944.100 – 951.900

Audio Compressor: 2 to 1 IFB, 100, and 200 Mode

Output Impedance: 50 ohms

Audio Input Levels: • 0 dBu for Line, RTS1 & RTS2

• -10 dBu for Clear Com

• -42 dBu for mic dry inputs (no phantom power)

• +/-50Vdc max

Audio Input Config: Balanced and Unbalanced, rear panel selectable for
Line, Mic. RTS 1, RTS 2, and Clear Comm

Audio Input Impedance: Greater than 2 K balanced, greater than 1 K unbalanced
at any gain setting

Gain Control Range: -18 dB to +24 dB (0 dB nominal center),
Menu selectable

Audio Input Jack: Standard XLR female connector

Input Power: 12 to 14 VDC typical, 200 ma. max.; Max. Input Range
6 to 18 VDC

Power Input Jack: Coax type, locking LZR RL26AE

Indicators: Backlit Liquid Crystal Display. Displays modulation
meter, frequencies, modes, rolloff, audio level,
and tuning groups.

Front panel controls: • MENU momentary pushbutton switch

• Power OFF-TUNE-XMIT, 3 position slide switch

• Select Up momentary pushbutton switch

• Select down momentary pushbutton switch

Rear panel controls: Input Mode Select, 4 section DIP switch

Weight: 9 ozs.

Size: 5.25” L (including connectors) x 3.25” W x 1.25” H

Specifications subject to change without notice.

Emission designator: 180KF3E

IFBT4td.indd

16 March 2007