User's Manual
IFB Receiver
Rio Rancho, NM
3
Introduction
Thank you for selecting the Lectrosonics frequency 
agile IFBR1a receiver. The design is the result of exten-
sive engineering experience with the most up to date 
components for demanding professional applications. 
The receiver will operate with any Lectrosonics IFB 
transmitter and any Lectrosonics wireless microphone 
transmitter in the IFB compatibility mode.
Applications for the IFBR1a range from on air talent 
monitoring of program audio and producer/director 
cueing during live broadcasts, to on location audio track 
monitoring and crew communications in motion picture 
production.
The receiver will drive earsets and headsets with a 
variety of impedance loads, and induction loop type 
listening devices. The unit can be configured as a single 
frequency device, or with multiple frequencies stored in 
memory for recall by pressing the volume control knob. 
The frequency set at turn on is defined by two rotary 
switches on the side panel. Additional frequencies are 
added to memory with either a scanning or direct entry 
(manual) procedure.
The housing is a rugged, machined aluminum package 
designed to survive abusive environments
Only the IFBR1a receiver is covered in this manual. 
Transmitters are covered in separate manuals.
Table of Contents
Safety Notes ........................................................................... 2
FCC Notice ............................................................................. 2
Features and Functions ........................................................ 4
Control Knob ........................................................................ 4
LED Indicator ....................................................................... 4
Headphone Jack .................................................................. 5
Mono Plug/Stereo Plug Usage ............................................. 5
Audio Level .......................................................................... 5
Frequency Adjustment and Tables ....................................... 5
Battery Instructions............................................................... 6
Basic Operation ..................................................................... 6
Scan Mode ........................................................................... 6
Add a New Frequency to The Next Open Channel .............. 6
Erase All 5 Channel Memories ............................................ 7
Multiple Transmitter Setup .................................................... 7
Advanced Operation  ............................................................ 8
Direct Entry Mode ................................................................ 8
Defeating the Switch ............................................................. 9
Troubleshooting ..................................................................... 10
Parts and Accessories .......................................................... 11
Specifications and Features ................................................. 12
Service and Repair ................................................................ 13
Returning Units for Repair ................................................... 13










