WisyCom CTK38 User Manual page 7

O
PTIONAL
VOX 38 - Voice Activated Circuit board
This device is useful to switch on automatically the carrier of the transmitter only when the
modulating signal is present on the TX's input. The circuit is mounted on a printed-circuit
board, that has to be factory-mounted in the transmitter.
Once the modulation audio signal reaches the pre-set threshold, the transmitter is
activated.
When the modulating audio signal is not more present, the carrier is switched off again,
after a pre-set delay time. Consequently the relevant MicroEar receiver is muted by its
built-in squelch circuit, preventing the listening of unwanted noise.
Two pre-setting values can be adjiusted by means of relevant screwdriver-trimmers
situated on the printed-circuit board: RT1 for audio "sensitivity" and RT2 for "delay" time.
CTK38 User Manual
VOX 38 board, mounted
on the CST 38 main board
Rev. 01
6