SQ000 Super Squelch SQ000 Super Squelch When supplied with discriminator audio the SQ000 will perform the operation of a Squelch Circuit, /CAS Generator, or a Repeater Maker. As quieting occurs, the SQ000 will turn on its audio switch and output the audio to a controller or transmitter. The audio path through the SQ000 has a gain of three. The SQ000 also produces a DC logic voltage change to be used by the controller as a CAS or input. A dipswitch selects whether the logic level is active high or low. The SQ000 automatically adjusts closure time with loss of signal. With a strong signal the switch will close in 0 milliseconds. Closure time automatically increases as the signal becomes noisier. A red LED lights whenever a signal is received and the squelch opens. The SQ000 connects directly to the audio delay header on most of the CAT controllers. A second header connector on the SQ000 is provided for the DL000C Audio Delay. /CAS Generator Figure describes how the SQ000 is used as a /CAS generator. In this configuration the SQ000 is connected to the transceiver port audio delay header of a CAT00B. Discriminator noise is sampled by the SQ000. When quieting occurs the SQ000 produces a DC voltage change that represents a input to the controller. Note: On the SQ000 dipswitch # must be ON. CAT00B SQ000 TRANSCEIVER RX AUDIO # TX AUDIO # PTT # J J CONTROLLER REPEATER RX AUDIO # TX AUDIO # PTT # # J DELAY BOARD Figure
Figure describes how the SQ000 is connected to the transceiver port audio delay header of a CAT000B. Note: On the SQ000 dipswitch # must be ON. CAT000 SQ000 TRANSCEIVER RX AUDIO # TX AUDIO # PTT # LINK PORT DELAY BOARD HEADER J9 J CONTROLLER REPEATER RX AUDIO # TX AUDIO # PTT # # J DELAY BOARD J DL000C Figure The SQ000 will support the DL000C Audio Delay. Connect the DL000C to the J connector of the SQ000. Set dipswitch # OFF to force the audio output through the delay board.
Repeater Maker Figure describes how the SQ000 is used as a Repeater Maker. Connect two transceivers to the SQ000. In this configuration the SQ000 monitors the discriminator output of the receiver. When quieting occurs the SQ000 /CAS logic output is used as a pushtotalk signal to key the transmitter. Set dipswitch # to ON for an active low output and dipswitch # to OFF to disconnect the pull up resistor and dipswitch # ON to pass the receive audio to the transmitter s modulation input. TRANSCEIVER # (TX) J PTT SQ000 TX AUDIO TRANSCEIVER # (RX) RX AUDIO V POWER SUPPLY Figure Dip Switch A fourposition dipswitch configures various functions of the SQ000. Switch This switch determines if the audio output is deemphasized. Switch # should be ON to deemphasize the audio output. Switch This switch controls the audio output path. When this switch is ON the audio output is directed to the controller at J pin. When this switch is OFF the audio output is directed to the J connector and the DL000C Audio Delay board. Switch This switch determines CAS/ output logic. This switch should be ON to set the CAS/ output active low and OFF to set the CAS/ output active high. Switch When this switch is turned ON a 00ohm resistor pulls up the /CAS output. This resistor is usually required when the /CAS output is set for active low. Audio Level Adjustment The SQ000 requires discriminator audio for proper operation. Speaker audio or deemphasized audio does not have the high frequency noise component required for proper operation. A minimum of 0mV of noise is required. Set the Squelch Adjust [R] to the full counter clockwise position. Verify that the red LED on the SQ000 is ON. Turn the Squelch Adjust clockwise until the red LED just goes OFF. Provide a signal to the input of the receiver and check that the red LED turns ON, CAS/ output on J pin is present and audio output is present on pin #.
SQ000 Diagram Figure SQ000 Part List Capacitor.00uF 0V C,C Capacitor.00uF V C,C Capacitor.00uF (SM) C Capacitor.0uF 0V C8 Capacitor 0.uF 0V C,C,C,C,C Capacitor.0uF V C0,C Capacitor 0uF V C9 Capacitor 0pF C,C Connector X J,J Diode BAT CR I.C. MC0 U I.C. NJM8L0UA U I.C. P8LPC U I.C. TC U I.C. TLC U I.C. TLC U LED SM DS Resistor K SM R0 Resistor.K SM R Resistor.K SM R Resistor.K SM R Resistor 0K SM R,R,R8,R,R,R Resistor K SM R8 Resistor 00K SM R,R9,R,R,R9,R0 Resistor 0K SM R Resistor 0 SM R Resistor 00K Variable R Switch Position SW Transistor N000 Q
V V C0 uf Controller Interface V Receiver Audio Input Date: Thursday, June 0, 00 Sheet of V C.00uf R8 C SWB R9 K.uf 00K Squelch Adjust R0 00K R 0K C 000pf R 0K R.K C 0pf C.00uf R TLC UA UB TLC C 0pf C.00uf R.K R 0K UD UA MC0 R 0K V uf C SWA 8 C.uf 00K C 000pf Sq Switch V TLC UA V R 0K V U NJM8L0UA VIN VOUT Receiver Audio Output Ground V In Output J Delay Interface Delay Audio Input Delay Audio Output Ground V In J U ICL CAP VOUT CAP 8 V GND C8.0uf UB R0 K R 00K V 0 9 UC 8 C.uf GND R 0K R8 0K CR BAT R9 00K C9 0uf V R 00K R 0K V C.uf U X/P. CMP/P0.0 0 CINB/P0. 9 CINA/P0. 8 AD0/CINB/P0. AD/CINA/P0. AD/CMPREF/P0. AD/CMP/P0. X/P.0 T/P0. Vcc TXD/P.0 RXD/P. 0 T0/P. 9 INT0/P. 8 INT/P. P. P. Vss P. V R 0 Squelch DS SWD Sq Switch K Q N000 C.uf R.K 8LPC SWC Polarity Title SQ000 Super Squelch Board Size Document Number Rev B B 900008