Icom IC-R20 Service Manual - Page 23

SECTION 5 ADJUSTMENT PROCEDURES 5-1 PREPARATION Almost adjustments must be adjusted on the adjustment mode. The shorten plug (see below) is required when entering the adjustment mode. ' REQUIRED TEST EQUIPMENT EQUIPMENT DC power supply Frequency counter GRADE AND RANGE Output voltage : 6.0 V DC Current capacity : 1 A or more Frequency range : 0.1-1000 MHz Frequency accuracy : ±1 ppm or better Sensitivity : 100 mV or better EQUIPMENT Digital multimeter Standard signal generator (SSG) GRADE AND RANGE Input impedance : 10 kΩ/V DC or better Frequency range Output level : 0.1-3000 MHz : 0.1 µV-32 mV (-127 to -17 dBm) ' ENTERING THE ADJUSTMENT MODE q Connect the shorten plug to the [SP] jack. w Push and hold [8 SET], [MR S.MW], [BAND] and [MAIN/SUB] keys, and then turn power ON. NOTE: Entering adjustment mode, keep on entering adjustment mode until dis-connect the shorten plug and turn power OFF. I OPERATION ON THE ADJUSTMENT MODE Change the adjustment channel or item [UP] : [MR S.MW] key Change the adjustment channel or item [DOWN] : [SCOPE] key Change the adjustment value : [R-DIAL] While entering adjustment mode, some adjustments must push [• LOCK] or [8 SET] keys to write the adjustment value to the CPU. Refer to following list in detail. KEY [• LOCK] [8 SET] OPERATION Write the REFERENCE FREQUENCY ADJUSTMENT value. Write the BFO ADJUSTMENT value. Write the AFC ADJUSTMENT value. Write the TRACKING ADJUSTMENT value. Write the S-METER ADJUSTMENT value. ' CONNECTIONS Standard signal generator to the antenna connector 0.1 V to 32 mV ( 127 dBm to 17 dBm) JIG Shorten I/O and GND line. 3.5(d) mm I/O GND 3-conductor 3.5(d) mm plug must be used. to [SP] jack Power supply to [DC] jack 6 V / 1 A IC-R20 5 - 1