Icom IC-7410 Instruction Manual - Page 91

9 ANTENNA TUNER OPERATION • Automatic tuner start (HF bands only) If you want to deactivate the tuner when the VSWR is 1.5:1 or less, use the Auto Tuner Start function and turn OFF the tuner. This function activates the tuner automatically when the SWR is high, and is controlled in the Set mode. (p. 86). • The tuner may not be activated if the TX power output is not stable longer than the specified time period in the SSB or CW mode operation. • PTT tuner start Tuning of the internal*/external antenna tuner starts when [PTT] is pushed on a new frequency that is more than 1% away from the last-tuned frequency. This function removes the "holding down [TUNER]" operation, and starts tuning on the first transmission on a new frequency. This function is turned ON in the Set mode. (p. 87). *Tuning starts if the internal antenna tuner is ON. ■ Optional external tuner operation • AH-4 HF/50 MHz AUTOMATIC ANTENNA TUNER The optional AH-4 matches the IC-7410 to a long wire antenna more than 7 m/23 ft long (3.5 MHz and above). • See page 18 for the transceiver and AH-4 connec- tion. • See the AH-4 instruction manual for AH-4 installation and antenna connection details. AH-4 setting example: For mobile operation Optional AH-2b antenna element For outdoor operation Long wire • AH-4 operation Tuning is required for each frequency. Be sure to retune the antenna before transmitting when you change the frequency- even slightly. q S elect the desired frequency for use with the AH-4. • T he AH-4 will not operate on frequencies outside the ham bands. w Hold down [TUNER] for 1 second. • " " blinks while tuning. e " " appears constantly when tuning is com- plete. • W hen the wire antenna cannot be tuned, " " disap- pears and the AH-4 is bypassed. At that point the an- tenna wire connection root is to the transceiver directly, and not via the AH-4 antenna tuner. r To bypass the AH-4 manually, push [TUNER]. [TUNER] R DANGER: HIGH VOLTAGE! NEVER touch the antenna element while tuning or transmitting. CAUTION: NEVER operate the AH-4 without an antenna wire or element. The tuner and transceiver will be damaged. NEVER operate the AH-4 when it is not grounded. Transmitting before tuning may damage the transceiver. Note that the AH-4 cannot tune when using a 1⁄2 λ long wire or multiple of the operating frequency. When connecting the AH-4, the antenna connector assignments are [ANT2] for the internal tuner and [ANT1] for the AH-4. The antenna icon in the LCD displays "ANT" when the AH-4 is connected and selected. • Antenna tuner of the IC-PW1/EURO When using an external antenna tuner such as that in the IC-PW1/EURO, tune when the internal tuner is turned OFF. After the antenna has been matched, turn ON the internal tuner. Otherwise, both tuners simultaneously tune, and proper antenna matching may fail. See the instruction manual included with each antenna tuner for their respective operations. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 84