Elecraft KPA500 Owner's Manual - Manual (Page 16)

16
Band Switching
Automatic Band Switching: The KPA500 automatically measures the frequency of the RF drive
and selects the proper band. The
PA KEY input must be connected to the driving transmitter.
Manual Band Switching: Tap any of the front-panel BAND switches to select that band.
Coordinated K3 and KPA500 Band Switching: When the optional AUX cable (pg 10) is
connected between the KPA500 and the K3:
 The KPA500 will follow the band selected on a K3 transceiver.
 Tapping a BAND switch on the KPA500 will cause the K3 to change bands accordingly.
Band switching control in which the KPA500 follows the transceiver band selection without
transmitting is available with other popular transceivers such as Icom and Yaesu with the
appropriate interconnection cable. See AUX Connector Interface on pg 26. However, the control
is one-way. The KPA500 cannot command the transceiver to change bands.
The automatic band selection function is active whenever the PA KEY is low (transmit
mode) and the transmitter is delivering RF drive to the KPA500. The automatic band selection
function overrides band selection made by any other means to protect the KPA500 from
damage by wrong-band operation.
Transmitting
The POWER (W) and standing wave ratio ( SWR) bargraphs are functional when the amplifier is in
standby ( STBY ). Twenty-five watts from the driving transceiver will illuminate the first POWER LED.
You may run up to 100 watts through the KPA500 in STBY.
1. Tap the operate/standby (OPER/STBY) switch and confirm that the STBY LED goes out and
the OPER LED lights.
2. Apply a few watts of RF drive and note that the POWER (W)
bargraph illuminates to indicate
the RF output power. Never exceed 40 watts of drive to the KPA500 in OPER mode. The
KPA500 will not amplify without the PA KEY signal. Note that an asterisk will appear on the left
side of the LCD display confirming that a valid PA KEY signal is being received from the driving
transceiver. If an underscore appears instead of the asterisk, amplifier operation is being inhibited
(See the
INHIBIT menu entry on pg 20)
NOTE
If you apply RF drive at a frequency below 1.6 MHz, between 26 MHz and 28
MHz, or above 54 MHz,
INVALID will appear on the LCD and the KPA500 will
not amplify.
(Continued on next page)