Lectrosonics LMa - Manual (Page 9)

Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM 9
Adjusting the Frequency
The left switch adjusts the operating frequency of the
transmitter up or down in 1.6 MHz steps. The right
switch adjusts the operating frequency of the transmit-
ter up or down in 100 kHz steps. It is suggested to use
the metering on the associated receiver to find a clear
channel. Turn the transmitter off and leave the receiver
turned on.
All 400 Series (and a number of earlier receivers) offer
front panel LCDs that indicate the correct transmitter
switch settings, and built in scanning functions to help
locate clear channels. Use the scanning functions on
these receivers to find a clear channel, then switch the
transmitter to the frequency settings indicated in the
receiver’s display.
The R400A, Venue Series and other Lectrosonics
receivers have an automatic scanning function called
SmartTune TM that automatically locates clear operat-
ing channels. If your receiver does not have a built in
scanning function, manually tune the receiver across its
band and find a frequency where little or no RF activity
is indicated.
After finding a clear channel, set the transmitter to this
new frequency, then turn it on and make sure the RF
signal is strongly indicated at the receiver. Be sure the
switch settings between the receiver and transmitter are
set exactly the same. If, for example, the 100K switch
is one click above or below the desired frequency, the
receiver will indicate RF, but no audio (or severely dis-
torted audio) will be produced.
0 1
2
3
4
5
6
7 8 9
A
B
C
D
E
F 0 1
2
3
4
5
6
7 8 9
A
B
C
D
E
F
Frequency Select Switch Settings
1.6M 100K
Input Jack
AUDIO LEVEL
Control
-20 LED
-10 LED
6) For microphone users, observe the Modulation
LEDs while speaking or singing at the same voice
level that will be used during the program. Gradu-
ally rotate the AUDIO LEVEL control clockwise until
the -10 LED glows green and the -20 dB glows
green with occasional red flickers. This indicates
full modulation and is the optimum setting for the
transmitter’s gain.
For musicians, gradually rotate the AUDIO LEVEL
control clockwise while playing the loudest notes
that will be played during the performance. It is ideal
for the -20 LED to briefly flicker red during the loud-
est passages.
7) Once the transmitter’s audio gain has been set, the
remaining components of the audio system can be
energized and adjusted.
Warning: DO NOT use the audio level control
for controlling the volume of your sound
system or recorder levels. This gain adjustment
matches the transmitter gain with the user’s
voice level and microphone positioning, or the
instrument output level.
Modulation LED Signal Level Table
Signal Level -20 LED -10 LED
Less than -20 dB Off Off
-20 dB to -10 dB Green Off
-10 dB to +0 dB Green Green
+0 dB to +10 dB Red Green
Greater than +10 db Red Red