Icom IC-PW1 Instruction Manual - Page 17

3 OPERATION s Antenna tuner operation The built-in automatic antenna tuner can match the antenna feed line impedance to 50 Ω when the feed line impedance is within 16.7 to 150 Ω for HF bands (VSWR 3:1) or within 20 to 125 Ω for 50 MHz bands (VSWR 2.5:1). Once the tuner matches an antenna, the tuning circuit condition is memorized as a preset point for each frequency range (100 kHz steps, 70 ranges). Therefore, when you change the frequency range, the tuning circuit is automatically preset to the memorized point. This antenna tuner is also used when the linear amplifier is turned OFF. ➥ Push [TUNER] for 2 sec. to start manual antenna tuning. • When the tuner cannot tune the antenna (SWR 1.5:1 or greater), the tuning circuit is bypassed automatically after 20 sec. While operating in the 50 MHz band, the antenna tuner does not start automatically. Push [TUNER] for 2 sec. to tune the antenna manually. s Protection circuit This linear amplifier has various protection circuits. D ALC circuit The ALC (Automatic Level Control) circuit automatically limits RF output power by controlling the input level of the exciter. This prevents transmission of distorted signals when the input signal level exceeds the allowable level. The ALC activates under the following conditions: - Output power of the linear amplifier exceeds 1 kW - Antenna SWR becomes 2:1 or more - Output power of the exciter exceeds 100 W D Cooling fans • The power supply cooling fans activate when the linear amplifier is activated and while transmitting. • The antenna tuner cooling fans activate when the antenna tuner is activated and while transmitting. • All cooling fans activate when the heatsink temperature of the final FETs reaches 50 °C (122 °F) or more. D Circuit breaker If the circuit breaker activates or the linear amplifier stops functioning, try to find the source of the problem, then push the circuit breaker button to fill the white parts. - Circuit breaker capacity: 20 A (U.S.A. version) 15 A (Europe version) D Linear amplifier protection circuit When a protection circuit is activated, a band indicator blinks to show a problem as described below. ➥ [AMP/PROTECT] lights red when a protection cir- cuit is activated. - Push [AMP/PROTECT] to cancel the protection circuit. Item 1 2 3 4 5 Indication [TEMP] [AUTO] [ALC] [VD] [ID] Possible cause The heatsink temperature of the final FETs exceeds 100 °C (212 °F). Power level of the 4 PA units becomes unbalanced. ALC control level exceeds the control range. Output voltage of the internal power supply exceeds 55 V DC. Current of the final FETs (ID) exceeds 50 A. 6 Current band's indicator Gain of the final FETs drops. Selected and When transmitting with different 7 current band's band selections between the lin- indicator ear amplifier and exciter. 8 [AMP/PROTECT] The power supply has a malfunction. 14