5- 19 REPEATER OPERATION

current is less than 10 PA and the battery lasts for about one year. When the backup circuit is not used, the VFO fre- quency returns to 144.000.0 MHz in the OFF Position of the power switch.

5-18 OPERATION ON EXTERNAL DC POWER (MOBILE OPERATION)

The TS - 780 also operates on external DC power (DCI 3.8 V* 15%) for mobile Operation.

Installation

The method of mobile Operation is basically the same as that of fixed Station Operation.

Select a suitable location for installation of the transceiver. The installation location may vary depending on the size and structure of car. The transceiver may be placed on the passenger’s seat; in this case, it should be secured with the seat belt so that it will not drop off the seat if the car Stops suddenly.

Mobile Antenna

Various types of mobile antennas are available for use o n 1 4 4 a n d 4 3 0 M H z b a n d s . Y o u can u s e a 1/4 wavelength whip antenna, ground plane antenna or 5 / 8 wavelength antenna.

Note:

Most roof mount antennas are designed so that the anten- na base is earthed to the car body. Mount the antenna securely referring to the instruction manual supplied with the antenna.

DC Cable

When the transceiver is to be operated from DC power, a DC power cable with an 7 A fuse should be used.

In DC Operation, please prepare a DC cable as Fig. 18.

DC power Cord

Fig. 18 DC Cable

Battary Capacity

During mobile Operation, the transceiver draws about 5 A of current, so a battery having about 35AH of capacity is sufficient for proper transceiver Operation. However, since the battery is given an additional load, it is advisable to use the transceiver while the car engine is operating. Note:

To insure safe driving of car, it is recommended that the transceiver be operated in fixed channel mode.

The TS-780 is capable of the following repeater opera- tions on the bands of 144 MHz to 146 MHz and 430 MHz to 440 MHz .

		Frequency		Shift
144 to 146 MHz	. D-A	- 6 0 0		k H z
	D-B	+	600	kHz
430 to 440 MHz	.D-A	-	7.6	MHz
	D-B	-	1.6	MHz

In the D - A Position, the transmitting frequency is

7.6MHz lower than the receiving frequency. In the D-B Position, the transmitting frequency is 1.6 MHz lower than the receiving frequency.

If the transmitting frequency is outside of the amateur band, the digital display goes out and no Signals will be transmitted.

Operating Procedure:

1)Turn the band switch to the Position representing the operating frequency.

2)Set the TX-OFFSET switch to the appropriate Position. The OFFSET indicator lights.

3)Turn the VFO dial to the desired receiving frequency,

and push the TONE switch. The built-in tone oscillator circuit (1,750 Hz) operates to send the 1,750 Hz- modulated Signal to operate a repeater Station. The TONE switch is a non-leck type so that, when the switch is released, the tone oscillator Stops sending the Signals.

The transmitting frequency is shifted 600 kHz down from the receiving frequency on the band of 144 to 146 MHz at D-A Position; and 7.6 MHz or 1.6 MHz down from the receiving frequency on the band of 430 to 440 MHz depending on the TX-OFFSET switch posi- tion. The shifted frequencies are digitally indicated.

If any of the shifted frequencies is outside of the amateur band, the digital display goes out, and no Signals will be transmitted.

The REV switch is used to check repeater input Signal. By depressing that switch, the TX and RX frequencies are reversed.

In case of other shift repeaters, set the SHIFT switch to SIMP, and the function switch to A-R or B-R.

For example, in case of a repeater Station with a shift of

+1 .6 MHz from 433 MHz, set the function switch to the A-R Position, VFO-A to 433.0 MHz and VFO-B to

4 3 4 . 6 MHz .

Then the TS-780 receives 433.0 MHz and transmits

434.6MHz Signals.

In a similar way, repeater operations of other shifts are possible.