The MX416 rugged digital microphone is intended for use in short
range wireless audio transmission applications for police, homeland
security etc. The RF output power is approx. 250mW and typical lineof-sight operating range is over 3 miles (depends on various factors).
The MX416 works as a pair. The transmitter is very small and
completely self-contained with a microphone and a Li-Ion battery
built-in. The battery is capable of running the MX416 continuously for
over 7 hours. The receiver is powered by an external dc supply and
has a output for driving a 16 ohm headset speaker.
The MX416 offers the following features:
• A secure digital audio link with very short delay.
• UHF frequencies that provide better radio signal penetration
The charging connector is a 4-pin size 00B LEMO connector. A
separate wall mount charger is provided thereby avoiding the need
for a cradle.
1.2 RF Output/ Antenna
The MX416 has a 50 Ohm RF output through a MCX jack. An
antenna is included for each unit.
MX416-R (Receiver)
1.3 I/O Connector
This is also a 4-pin size 00B LEMO connector. It has 2 pins for power
and speaker/audio output.
1.4 RF Input/ Antenna
This MCX jack is an rf input connector for an antenna. A short omni
whip (supplied) can be used for short distances up to a few hundred
feet or a high gain omni (or directional antenna if the application
permits) can be connected using a adaptor cable (optional).
The MX416 has an on/off switch. This shuts off power to the entire
transmitter/ receiver.
2.2 Setup.
Since the MX416 works as a pair, it is shipped with a sticker
indicating the operating frequency e.g- 650 MHz. If you have ordered
multiple sets, please ensure the correct pair is used. The user has to
connect the antennas, power & audio cables & the link is ready to
work. There is no specific setup procedure.
2.3 Electrical Interface.
The transmitter has the following interfaces:
2.3.1 Charger Input
a) The charger input is actually a battery charger connection. The
external wall mount battery charger is connected to this jack.
b) This input is switched and protected against reverse polarity.
c) Charging is performed in the power “off” position.
2.3.2 Microphone
a) The MX416 uses an electret microphone and is built into the case.
b) For volume orders, provision for connection of an external
microphone can be made.
2.3.3 RF output to antenna.
a) The RF output connector is a 50
b) The RF output power is approx. 250 mW (transmit).
2.3.4 Power Input
a) The receiver works on unregulated dc power of 6 – 14 V DC.
Current consumption is only 150 mA.
2.3.5 Speaker Output
a) The MX416 receiver is capable of supplying 30mW into a 16 ohm
headset speaker.
b) If an external amplifier will be used, the speaker/audio signal
should be terminated by a parallel combination of a 22 ohm
resistor and a 0.1uF capacitor. If you need assistance with this
arrangement, please call Avalon RF Engineering and we will
gladly help.
2.4 Interconnecting.
The interface to the transmitter is:
Pin
Function
Number
1 Power/Charge Return (-)
2 N/C (No Connection)
3 N/C (No Connection)
4 Power/Charger Input (+)
Before applying power, make sure all connectors and all antennas
are properly connected.
NOTE
The transmitter will not transmit unless it has an antenna.
The transmitter has only 1 operator control (the on/off switch) and no
indicators (to allow for covert applications). The receiver also has the
same control and no indicators.
This product was primarily designed for covert/ secure
communication applications and therefore may seem to be lacking
some features. For OEM applications, please contact Avalon RF with
your requirements.
Follow the guidelines below to optimize the operating distance/range:
a) The transmit antenna’s location is vital to a radio link. Keep the
transmit antenna completely clear of any metal object or carbon
composite materials. If the transmitter is placed on a person’s
body, the transmit antenna should be placed to clear the body,
particularly the head.
b) To get the optimum range, the transmit antenna should be located
as high above the ground as the application permits.
c) The receive antenna should be generally in view of the transmit
antennas radiation pattern. If you have any doubts or concerns,
please call Avalon RF Engineering at (619) 401-1967.
d) Do not place the antennas in the vicinity of other antennas even