Installation Manual

Maximizing Antenna Performance with the ATU

74 750.001.003

Revised June 1999

Inc.

Adjusting Performance with a Toggle Switch ATU

Step 1: IMPORTANT! Ensure that the wires running from the

toggle switch are plugged into the header. This

sometimes disconnects during shipping. The connector

should be oriented such that position 1 on the rotary dial is

connected to pin 1 on the header (Figure 30).

Step 2: Put the toggle switch into position 0, turn the rotary switch

knob, and watch the voltage meter. Note the position that

provides the peak voltage level on the voltage meter (if

any).

D.C. VOLTS

Optimum Tuning

Figure 31 Voltage meter showing optimum tuning

Step 3: Repeat Step 2 with the toggle switch in positions 2 and 1.

There are a total of 30 combinations available (10

positions on the rotary switch, and 3 on the toggle switch)

for determining optimum tuning. Check all positions for

peak meter level.

Step 4: Reset the positions of the rotary dial and the toggle switch

that gave the highest voltage on the meter (0 to 4 volts). 1

to 2 volts is a typical optimum reading.

Note: The ATU must be mounted with its connectors

pointing down for the voltmeter to read accurately.