Fat-2_Calibration_Procedure 电路图.pdf

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1、FATMAN: FAT2 CALmRATIONPROCEDURE. The test signal is always a 1kHz Sinewave. Start test with all push buttons out, Gains pots in mid-position, Compressor pots anti-clockwise. 1. POWER SUPPLY. Check Testpoint v+ for + 15 vdc (:f: 0.25v). Check Testpoint V- for -15 vdc (:f: 0.25v). ,J . Check R29(Nr C

2、84) for. 1 I volts dc (:f:lv). : Check R30 for approx 95 volts dc. (:f:5v). Check XLR Pins 2 & 3 for +48 vdc (:t3v). with 48V switch ON. 2. OFFSET. Using a DC Voltmeter adjust RV3 for +OO mVat TP3. Press KNEE switch IN and check the voltage changes to +200 mV :f:15 mY. 3. BIAS: Connect Input to LINE

3、 JACK and adjust RVl8 for a reading of 0.5% Distortion. (:to. 1%) Input source = 0 dBu. Output = distortion. 4. GAIN. With the Input connected to LINE Jack, and the OUTPUT GAIN pot at MAX set the Output Level for + 15.0 (:to.3) dBU using RVl1. Input source = 0 dBu. Set the COMPRESSOR ON switch IN. S

4、et the Output Level for + 15.0 (:to.3) dBu (RVI0) Output = dBu. Set the OUTPUT GAIN pot to Centre. Set the Output Level for +0.0 (:to.3) dBu (RVI3) 5. llIRESHOLD Set llIRESHOLD and RATIO pots fully clockwise. Input source = -20 dBu. Set RV4 initially fully clockwise and note value, then slowly anti-

5、clockwise until the Output Output = dBu. Value changes by 0.2 dBu. 6. METER CAL Set llIRESHOLD and RATIO fully anti-clockwise. Input source = +4 dBu. Verify the Output Value is +4.00 dBU. Trim gain pot if necessary. Output = dBu. Adjust RV5 so the Meter is reading Zero dB. Set the METER switch IN. Adjust RV7 so Meter is reading Zero dB. Set llIRESHOLD fully clockwise. Vary RATIO so the Output reads -2.00 dBu. Set RV6 so Meter is reading -6 dB THIS PROCEDURE IS INTENDED FOR USE BY A QUALIFIED TECHNICIAN ONLY. WARNING! HIGH VOLTAGES EXIST ON THE PCB. RadioFans.CN 收音机爱 好者资料库