Icom IC-7000 Antenna Tuner Operation, Optional AT-180 Automatic Antenna Tuner operation

ANTENNA TUNER OPERATION 10

■Optional AT-180 AUTOMATIC ANTENNA TUNER operation

The AT-180 automatic antenna tuner matches the IC- 7000 to the connected antenna automatically. Once the tuner matches an antenna, the variable capacitor angles are memorized as a preset point for each frequency range (100 kHz steps). Therefore, when you change the frequency range, the variable capacitors are automati- cally preset to the memorized point.

NOTE:

•The AT-180 can match both HF and 50 MHz

bands. However, operation is different for the HF

and 50 MHz bands.

• When connecting the AT-180, the IC-7000’s output

power must be set over the 10 W. Otherwise, the

AT-180 may not be tuned correctly. (AT-180’s min- imum operating input power is 8 W.)

CAUTION: NEVER transmit with the tuner ON when no antenna is connected. This will damage both the transceiver and antenna tuner.

The AT-180 cannot be used for the 144/430 MHz

bands. When operating on the 144/430 MHz band, pushing [TUNER/CALL] selects the call channel

(p. 102).

[TUNER/CALL]

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D Tuner operation

•For the HF band:		•For the 50 MHz band:
Push [TUNER/CALL] to turn the tuner ON. The an-		Push [TUNER/CALL] for 1 sec. to tune the antenna.
tenna is tuned automatically during transmission		If “ ” indicator blinks slowly while transmitting,
when the antenna SWR is higher than 1.5:1.		push and hold [TUNER/CALL] for 1 sec. again to re-
•When the tuner is ON, “	” indication appears.	tune the antenna.

D Manual tuning

During SSB operation on HF bands at low voice lev-			Through inhibit (HF bands only)
els, the AT-180 may not be tuned correctly. In such			The AT-180 has a through inhibit condition. When se-
cases, manual tuning is helpful.			lecting this condition, the tuner can be used at poor
Push [TUNER/CALL] for 2 sec. to start manual tun-			SWR’s. In this case, automatic tuning in the HF bands
			activates only when exceeding SWR 3:1. Therefore,
ing.
			manual tuning is necessary each time you change the
•CW mode is selected, a side tone is emitted, and “		”
			frequency. Although termed “through inhibit,” the tuner
indicator blinks; then, the previous mode is selected.
			will be “through” if the SWR is higher than 3:1 after
If the tuner cannot reduce the SWR to less than 1.5:1			tuning.
after 20 sec. of tuning, “	” indicator disappears.
In this case, check the following:			CONVENIENT
•the antenna connection and feedline			•Tuner sensitive condition (HF bands only)
•the antenna SWR (p. 36; meter function)			If you require critical tuning at any time during trans-

mission, select the tuner sensitive condition. See p. 133 for selection.

•Automatic tuner start (HF bands only)

If you want to turn OFF the tuner under conditions of VSWR 1.5:1 or less, use “automatic tuner on” and turn the tuner OFF. See p. 132 for turning the function ON and OFF.

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