Manual

TECHNICAL NOTES
TECHNICAL NOTESTECHNICAL NOTES
TECHNICAL NOTES
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CircuitdetailsofRadioInterface.
TheoptoisolatorsOPT1andOPT2provideisolationoftheMaxonradiotransmitkeyandbusylinesbetweenthe
Q80moduleandassociatedequipment.
Tra
TraTra
Transmitter Key
nsmitter Keynsmitter Key
nsmitter Key
TheMaxonradiotransmitteriskeyedONbypullingtheTXKEYlinetoground.ThetransmitterkeyedKYLED3will
turnON.TheTXKEYlineONcurrentisapproximately10mA.
Receive Busy
Receive BusyReceive Busy
Receive Busy
The Maxon radio busy output line switches opto isolator OPT2 ON via transistors Q4 and Q5 when the radio
receiverisbusy.Thebusy/muteMULED2willturnON.ThebusyoutputlineBUSYwillsinkcurrenttogroundvia
theoptoisolatoroutputtransistor.TheBUSYoutputlinecansinkamaximumof10mA.
Transmitter Audio Level
Transmitter Audio LevelTransmitter Audio Level
Transmitter Audio Level
PotentiometerVR2isusedtosettheMaxonradiotransmitaudiolevel.Therequiredlevelis–3dBmfor+/-3kHz
(+/1.8kHz)transmitterdeviation.
Note Set +/- 3 kHz deviation for 25 kHz channel spacing and +/- 1.8 kHz for 12.5 kHz channel spacing i.e.
narrowbandchannel.ThesearetherequiredlevelswhentheQ80Moduleistobeusedwith
QTech RTU
modules.
Receiv
ReceivReceiv
Receiver Audio level
er Audio leveler Audio level
er Audio level
PotentiometerVR1isusedtosetthereceivedaudiolevel.Therequiredaudiolevelis+/-3kHz(1800Hz)deviation
ofMaxonradioreceivedsignalproduces–15dBmaudiooutput.
Note Set +/- 3 kHz deviation for 25 kHz channel spacing and +/- 1.8 kHz for 12.5 kHz channel spacing i.e.
narrowbandchannel.ThesearetherequiredlevelswhentheQ80Moduleistobeusedwith
QTech RTU
modules.
Audio Level Adjustment
Audio Level AdjustmentAudio Level Adjustment
Audio Level Adjustment
The transmit and receive audio levels are preset by QTech  prior to delivery and should not normally require
adjustment.
Note The 600 ohm modem line terminating resistor in the QTech  RTU modules should be removed, i.e. not
installed.
Tosetthetransmitandreceiveaudiolevelsproceedasfollows: