Lectrosonics R1 Operating Instructions And Troubleshooting Manual page 5

HEADPHONE JACK (fig. 1)
On the front panel is a 3.5mm mini phone jack to accommodate 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.
OUTPUT DRIVE LEVEL ADJUST (fig. 2)
On one side of the receiver unit is a sliding door covering an Output Max Level screwdriver adjust potentiometer. The
potentiometer can be adjusted to match high or low impedance earphones to prevent blasting.
MONO PLUG/STEREO PLUG SWITCH (fig. 2)
Also behind the sliding door is a Mono/Binaural switch. When
using a single earphone with a mini phone plug (tip & shield), set
the switch to MONO PLUG. To provide Monaural output to both
earphones of a dual headset with a stereo mini plug (tip, ring &
shield), set the switch to STEREO PLUG.
Warning! Do not insert a mono plug with the switch in the STEREO PLUG position. This
will short the jack ring to the sleeve and cause high distortion and short battery life.
MAX LEVEL (fig. 2)
Headphones and ear pieces vary widely in their sensitivity and their impedance making it impossible to design a
receiver with a fixed output power level that is correct for all situations. The MAX LEVEL control on the side of the
receiver is used to adjust the maximum power that can be delivered to the user selected headphones. Low impedance
phones (16 to 50 Ohms) will have the MAX LEVEL control set in a counter-clockwise direction to limit the maximum
output power to a reasonable level. High impedance phones (600 to 2000) Ohms) will have an inherently lower power
level due to their high impedance.
ADJUSTING THE MAX LEVEL CONTROL
Set the control fully counter-clockwise (minimum power level) then adjust the front panel volume control for the desired
gain. If there is excessive distortion on loud sounds adjust the MAX LEVEL clockwise thereby increasing the power
level. Use only the power level necessary for safe hearing levels.
RF
RF
Mixer
Filter
Amplifier
Frequency Synthesizer
Memory
Controller
Audio
IF Amp/FM
Filter
Detector
Pilot
Tone
Detector
Disc
RSSI
Control
Panel LED
Figure 3 - R1 Block Diagram
Rio Rancho, NM – USA
Knob
PB Switch
Pwr On/Off,
Compandor Amp
Audio Level.
Control
Pilot
Tone
Mute
On/Off
IFB Receiver
MONO PLUG
MAX LEVEL
STEREO PLUG
Figure. 2 - Max Level and
Mono Plug/Stereo Plug Switch
2p
Audio Out
100n
2.5vdc
S
T
100n
R
2.5vdc
MAX
LEVEL
MONO (Open)
BINAURAL (Closed)
5V
Regulator
9V
Battery
Earphone
Cord
(Ant.)
5