7
Frequency Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
AUDIO LEVEL CONTROL
Used to adjust the audio input level for proper modulation.
AUDIO LEVEL LEDS
Indicate the proper setting of the MIC LEVEL control.
The two audio level LED’s are bi-colored (red/.green) and indicate 5 levels -
Off - Off
no audio modulation
Green - Off
low audio
Green - Green moderate audio
Yellow - Yellow full audio
Red - Red
limiting
ANTENNA
The flexible wire antenna supplied with the transmitter is cut to 1/4 wavelength of the center of the frequency block
(the frequency range) of the transmitter. It is removable via an SMA connector. The SMA connector is a 50 Ohm RF
port which can also be connected directly to test equipment. Replacement antennas are available in pre-cut lengths
for specific frequency blocks, or as a kit with instructions to cut the antenna for any frequency block.
ADJUSTABLE LOW FREQUENCY ROLL-OFF
A 18dB per octave low frequency roll-off is provided in the audio section, with the -3dB point adjustable from 35Hz to
150Hz. The actual roll-off frequency will vary somewhat according to the low frequency response of the mic capsule
being used.
The low frequency roll-off control is used to reduce the undesirable effects of very low frequency audio often pro-
duced by air conditioning systems, automobile traffic and other sources. Excessive low frequency content in the
audio input can cause overload of the program audio in recording applications. In sound reinforcement systems,
excessive low frequency content can cause excessive power amplifier drain or even damage to loudspeaker sys-
tems. A common example is wind blowing across a microphone, causing very high levels of low frequency audio
(“wind noise”). By rotating the roll-off control clockwise, the hinge point of the roll-off is increased to reduce the level
of low frequencies. In low noise situations, such as a motion picture production set indoors where environmental
noise is minimal, the control can be rotated counter-clockwise to permit low frequency audio to be captured.
THE BELT CLIP
The belt clip may be removed for special applications by removing one screw.
USE ONLY THE SCREW THAT IS SUPPLIED
The circuitry is tightly packed into this unit. A longer screw will permanently damage the transmitter! Use only
Lectrosonics PN:28528 which is a Phillips head, 4-40 x 3/16", FL100 screw.
