Computer Automation Technology CAT-800, Manual

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6-2
Receive Audio De-Emphasis
If the controller is supplied with discriminator audio it may be necessary to de-emphasize the audio.
With Jumper P2 installed a 0.0047uF capacitor is placed across the feed back resistor on the audio
amplifier. This capacitor causes the high frequency response of the receiver’s input amplifier to roll off
producing de-emphasis. If the controller is supplied with processed audio, remove the jumper.
Transmit Audio Adjustment
Once the receive audio is adjusted, key-up and send a DTMF tone. Monitor the transmitter output.
Adjust the TX1 Audio control (R22) as required to set the transmitter deviation to 3 KHz or as desired. If
the transmit audio adjustment is very sensitive and you find the control near minimum, it is strongly
recommended that an external resistor voltage divider be installed at the audio input of the transmitter.
Terminate the TX1 audio level by placing a 100 ohm resistor from the transmitter audio input to ground.
Install this resistor at transmitter’s modulation input not at the CAT - 800’s TX1 audio output .
Voice Synthesizer Audio
Compare the received and synthesized voice audio and adjust the VOC Level control (R51) as desired.
The synthesized voice should be lower than the receiver’s audio level and never exceed 3KHz deviation.
Over driving the Voice synthesizer audio will cause some letters to sound more alike. Repeat the above
procedures for Port #2 and Port #3 using the RX2, TX2, RX3 and TX3 level controls.
Interface Review
Verify the following eight conditions have been met.
INTERFACE REVIEW
1 Is J1-17 connected to the repeater chassis?
2 Is J1- 10 connected to the repeater transmitter’s PTT inpu t?
3 Is J1- 11 connected to the repeater transmitter’s modulation input?
4 Is J1-6 connected to the repeater COR output?
5 Is the COR level changing from less than 0.2 VDC to greater than 3.0 VDC?
6 Is dipswitch #1 on for active low COR voltage change or off for active high COR?
7 Is J1- 13 connected to the repeater receiver’s audio output?
8 Is the receive audio input level adjusted for 220mVAC at the RX1 test point?
LED Display Indicator
The CAT-800 has six led indicators to display operational status. The green POWER led indicates power is
applied and that the five and three volt regulators are operational. Three green leds indicate the input
status of the three ports. An active COR input on J1-6 will light the Port-1 led. However if Zone 1
Channel 2 is enabled an active logic input on J-4 from a CTCSS decoder must also be present before the
Port-1 led will light. This is also true for the Port-2 and Port-3 leds. The amber led indicates a DTMF tone
is being decoded. A green led indicates INTERNET activity. Steady green indicates the CAT-800 is
connected to the Internet. A flashing green indicates data is being transferred.
Power Supply
The CAT-800 is powered by an external 12VDC power supply. Connect the positive lead of the supply to
the center pin of the coaxial power connector and the negative lead to the outer conductor. The power
connector is a 2.5/5.5mm plug.
NOTE: Do not back-feed 12VDC power through J1-16. This is an output not an input and is not
protected by the fuse and transorb. A short on the board could result in burned tracks. If necessary,
only replace the fuse with a 0.5A fast blow.
Connector Kit
Included with the controller is a connector kit containing a 25 pin “D” connector to mate with J1 and a
2.5mm power plug (center pin is [+]).