User's Manual

IFB Receiver
Rio Rancho, NM
5
Headphone Jack
A 3.5 mm mini phone jack accommodates a standard
mono or stereo type 3.5 mm plug. The unit will drive
low or high impedance earphones. The jack is also the
receiver antenna input with the earphone cord acting as
the antenna. The cord length is not critical but must be
at least 6 inches minimum.
A simple strain relief to avoid accidental disconnection
can be applied with the included small Velcro hook and
loop strip. Attach the adhesive strip side to the side of
the receiver with the opening end of the strip up. Place
the cord in the strip and secure.
Mono Plug/Stereo Plug Usage
A mono or stereo TRS (tip-ring-sleeve) plug can be used
with the headphone jack. When a mono plug is inserted,
the circuitry senses the ring to sleeve short and automati-
cally switches off the ring amplifier to prevent excess bat-
tery drain. To reset, switch the power OFF, then back ON.
Audio Level
Headphones and ear pieces vary widely in sensitiv-
ity and impedance making it impossible to design a
receiver with a fixed output power level that is correct
for all situations. High impedance phones (600 to 2000)
ohms will have an inherently lower power level due
to their high impedance and likewise low impedance
phones may be extremely loud.
CAUTION! Always set the audio level knob to
minimum (counter-clockwise) when plugging
phones into the jack, then adjust the knob for a
comfortable audio level.
Frequency Adjustment and Tables
Two rotary switches adjust the frequency that will be set
when the receiver is turned on. The 1.6M is a coarse
adjustment with 1.6 MHz steps and the 100K is the fine
adjustment that makes 100 kHz steps.
Frequency tables are provided on the web site to list the
frequencies in MHz (megahertz) that correspond to the
hex numbers on the rotary switches. Go to the web site
home page at: www.lectrosonics.com/US. Mouse over
the Support tab at the top of the page, then click on
Frequency Tables. You will be taken to the support site
page with a complete listing of all available blocks.