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Basic operation with any transceiver – Elecraft KXPA100 Manual User Manual

Page 30

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Basic Operation with any Transceiver

The following instructions assume that your transceiver is connected to the KXPA100 amplifier as shown in
Figure 5 on page 18. If you are using a KX3 with the KX3 to KXPA100 Adapter Cable connected as shown in
Figure 3 on page 14, refer to Operation with the KX3 using the KX3 to KXPA100 Adapter Cable on page 24.

ALC Adjustment: If your transceiver adjusts RF output power in steps greater than 0.1 watt, the

KXPA100 Automatic Level Control (ALC) circuit must be adjusted to provide the correct output power.
See Adjusting the KXPA ALC on page 46

Initial Basic Operation Settings

On the KXPA100, set the

3 dB ATTEN

switch as follows:

o

Set the switch to

OUT/AUTO

if the driving transceiver is not capable of more than 5 watts

output.

o

Set the

3 dB ATTEN

switch to

IN

when using the amplifier with any other transceiver capable of

more than 5 watts output. Never apply more than 10 watts of RF drive to the KXPA100 at any
time, even with the

3 dB ATTEN

switch set to

IN

.

Switch the KXPA100

OFF/ON

switch to

ON

. The

ON

LED will light. The

ATT LED

will light if you

have the

3 dB ATTEN

switch set to

IN

.

Connect a 50-ohm dummy load or antenna feed line that presents an SWR of less than 1.5:1 to the
active KXPA100

ANT

connector. If you have the optional KXAT100 ATU, the

ANT 1 or ANT 2 LED

will light indicating which antenna connector is active and the

Man MODE

LED will light. If you do not

have the KXAT100 ATU installed use the

ANT 1

connector. Hold the KXAT100

AN T

switch to change

the selection. Be sure you have a suitable load attached to the active antenna connector.

Amplifier Basic Operation

Fault Conditions: If the

Fault

LED on the KXPA100 front panel lights, refer to Faults on

page 32 for a description and remedy.

Apply about 2 watts of RF drive to the KXPA100:

Transmit Mode: The

TX LED

on the amplifier front panel will light indicating that it is in transmit

mode. (If the LED does not light, the amplifier remains in receive mode and the RF drive simply passes
through. Check the KEY line connections and make sure your transceiver is pulling the KEY line to
ground on transmit.)

Band Switching: The amplifier senses the frequency of the RF drive and automatically changes to the
correct band.