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INSTALLATION
Your CES Model 710 DTMF Encoder microphone requires filtered +10 to +15 VDC to power it's audible sidetone,
keypad illumination, and microprocessor. The 710 is available with factory installed mating connectors for many
popular transceivers. The connectors are configured to receive the required operating power at the radio microphone
jack.
Some transceivers may not already have a provided voltage source output available at the microphone jack. In this
case, a minor modification will be necessary and can be accomplished by a two-way radio technician. Locate a
switched and filtered source of +10 to +15 VDC within the radio and connect it to an unused terminal on the
microphone jack. If you are using a microphone with a factory-installed connector: use the terminal associated with
the microphone Blue wire. In the case where no spare or unused connection is available, determine an appropriate
function that is otherwise not going to be used, such as "handset audio", or other.
It is important to utilize a filtered voltage source for the microphone operation. If alternator whine or other ignition
noise is experienced on the transmitted audio, another voltage source should be located and used. In severe cases, a
filter available from an appropriate supplier should eliminate the problem.
If your microphone was ordered without an installed connector, then install a connector on the Model 710
microphone cord as follows:
Cable Wire Color Function
BLUE + 12 VDC
RED Push-To-Talk (logic low)
WHITE TX Audio Output
BLACK CTCSS Hang Up (logic low)
SHIELD Audio/Analog Ground
YELLOW Power & Logic Ground
Jumper JP2 - Microphone Low/Power Ground Isolation Jumper
Jumper JP2 is used to isolate the microphone low in the microphone from the logic and power ground. If the voltage
supplied to the microphone is not well filtered (or if noise is experienced on transmit), or for transceivers that
require separate ground returns, remove (cut) jumper JP2.
CTCSS Hang Up is a logical function that will normally provide an off-hook (open-circuit) or on-hook (closed-
circuit) to the radio for CTCSS "monitor", or other applications. This requires a grounded hang-up clip for the
microphone.
For applications where an open circuit is required for an on-hook condition (off-hook=closed circuit), a logic
inverter option is available.
