Tait Orca 5000 Service Manual

Also see for Orca 5000: User manual

Contents

F - 6 Tait Orca 5000 accessory connector June 2003 IPN: M5000-00-105Accessory connector signaldescriptionsRX-DET-AF-ACCThe RX-DET-AF-ACC line carries unprocessedreceive audio from the output of the detector IC.MOD-AUDIOThe MOD-AUDIO line is used during calibra-tion to set up the modulation balance and bysome accessories, such as modems.+7V5-ACCThe +7V5-ACC line supplies +7.5 V to accesso-ries and is limited to 20 mA maximum. Theoutput voltage itself will change depending onthe battery voltage level, and there will besome voltage differential between the batteryvoltage and 7V5-ACC, depending on thecurrent drawn by the accessory.RXD-ACCThe RXD-ACC line carries data from the acces-sory connector to the controller during taskssuch as radio programming and calibration.TXD-ACCThe TXD-ACC line is a digital data line fromthe microprocessor and carries synchronousdata from the controller to the accessoryconnector during tasks such as radio program-ming and calibration.SENSE-0-ACCSENSE-0-ACC is used to turn off the radioísinternal speaker. To turn off the internal speaker,tie SENSE-0-ACC to GND by shorting link 1(LK1). The external speaker outputs are alwaysactive.SENSE-1-ACCOn conventional radios, SENSE-1-ACC is anoutput which follows the squelch detect line.On trunked radios, SENSE-1-ACC is a currentlyunused input.EXT-MICThe EXT-MIC signal is an analogue input fromthe microphone of an accessory.Connecting a microphone to EXT-MICautomatically turns off the radioís internalmicrophone.EXT-PTTThe EXT-PTT is an analogue signal from theaccessory interface to the control area andindicates an external request for PTT andexternal function buttons.GNDThe GND pin is the ground point of the acces-sory connector.BUTTON-1 and BUTTON-2Two external accessory function buttons areavailable, BUTTON-1 and BUTTON-2.The sensing of the external function buttons isdetermined by a voltage divider on EXT-PTT.This consists of a 27 kΩ pull up to 5 V insidethe radio and a pull down resistor on the acces-sory PCB. The resistor pull downs forBUTTON-1 and BUTTON-2 are as follows: PTT function: resistor pull down 0 Ω,voltage level on EXT-PTT is 0 V; BUTTON-1 function: resistor pull down12 kΩ, voltage level on EXT-PTT is 1.5 V; BUTTON-2 function: resistor pull down27 kΩ, voltage level on EXT-PTT is 2.5 V.These resistors are already fitted to the acces-sory PCB.EXT SPKR +/–The EXT SPKR +/ñ line can be used to drive anexternal speaker. Neither terminal should begrounded, as the output is differential.RFThis pin provides a connection for accessoriesrequiring RF, such as the RF speaker micro-phone. When an RF accessory is connected,the main antenna is switched out.