ELECRAFT KPA1500 Installation and operating instructions

Rev: 2.1
KPA1500 Connections to the Icom IC-7300
Application Note
June 2018 Rev 2.1
Background
Many operators want to use the Elecraft KPA1500 amplifier with their Icom IC-7300 transceiver. This
Application Note will discuss how this can be done with the Icom IC-7300. Many other Icom radios can
likely be adapted to work with the KPA1500 using the techniques described here.
Connecting your radio to the KPA1500
You will be connecting the KPA1500 to the SEND jack on the rear of the Icom transceiver.
Here's the wiring diagram from the IC-7300 Owner's Manual. Item #9 below is the SEND jack. Use the
cable terminated in dual RCA/Phono plug that was supplied in the box with the KPA1500 to make this
connection.
While the KPA1500 can accommodate it, there is no need to use the ALC connection with the KPA1500
unless the transceiver vendor requires its use.

Rev: 2.1
Connect the other end of the RCA cable to the KPA1500's KEY IN jack ( Item #10 in the image below) from
the KPA1500 Owner's Manual.
Connecting the CI-V system
The KPA1500 includes the ability to read the VFO frequency directly from the Icom radio using Icom’s CI-V
communication system.
After Training the Tuner built into the KPA1500, it will be able to pre-select the tuning elements needed
directly from memory as you QSY between bands or even frequencies within a band.
To make this work, use the Elecraft cable, (Elecraft part number E980229) to the XCVR SERIAL port on the
KPA1500 and the Remote port on the Icom radio. See item #6 in the Icom rear panel image above for the
Remote port location.
Setting up the CI-V connection in the KPA1500
In this section, we will be configuring the KPA1500 and the Icom radio so that the KPA1500 can read the
VFO frequency automatically as you change bands and frequencies.
Please find the menu items below and make the designated changes.
Menu item
Value
KPA1500
RADIO TYPE
ICOM

Rev: 2.1
SERIAL SPEED XVCR
4800, 9600 or 19200
ICOM radio
CI-V Baud Rate
4800, 9600 or 19200
Must agree with KPA1500 setting
CI-V Output (for ANT)
ON
Note: All other Icom CI-V menu settings are assumed to be set to their Defaults as documented in the IC-
7300 Owners Manual
Procedure for Training the Tuner of the KPA1500
Overview
We will be stepping through each band where you have an antenna connected to the KPA1500, where
you’ll selecting the top, bottom and places in the middle of each band where you expect to operate. At
each of these points, we will be causing the Icom radio to emit a steady-state, CW RF signal for the KPA1500
to use while it executes a Full Tune Cycle. Since the KPA1500 contains an Automatic Tuner, it will
remember the settings it finds at each of the points in the band. This is referred to as 'Training the Tuner'.
The following sequence assumes that the Icom and KPA1500 are connected as discussed above.
Set up
●On the Icom, prepare it to produce a constant 25 watts in CW mode.
●On the KPA1500, Tap the ANT button to select the appropriate antenna for the selected band.
The ANT LED will light solidly indicating the antenna port selected.
●On the Icom radio, select the the appropriate band. Then, adjust VFO A to the lowest spot in that
band where your antenna will work.
For each VFO Setting perform the following to Train the Tuner in the KPA1500
●Tap the ATU TUNE button. The ATU IN light will begin to flash to indicate it is waiting for RF from
the transceiver.
●Apply 25 to 50 W of transmit drive. You will hear the relays searching for a match.
●When the relays stop, the ATU IN LED stops flashing, indicating Full Cycle Tune success.
●The resulting match is automatically stored in the appropriate memory bin.
●If a match cannot be found, the red FAULT LED illuminates, NO MATCH is shown on the LCD, and
no settings are stored. The ATU can create a match for SWR as high as 10:1.
●If no match is found, make sure the correct frequency band and antenna are selected.

Rev: 2.1
●You can use the KPA1500 Utility Operate panel to observe Full Cycle Tune activity and
transmission line/ antenna system SWR.
●If you have multiple antennas on one or more bands, repeat this procedure for each antenna port
and frequency combination. The KPA1500 tuner can remember settings for both antenna ports
separately.
How do you know how many times per band is needed to fully train the tuner?
See the Appendix of the KPA1500 Owners Manual for a table of all the frequencies to make it easier to
choose the right ones for your station.
Make it Easy for Your Tuner to Remember what it was Trained to Do
Once you have fully trained your KPA1500 tuner on all bands and all Antennas, you can save your work
using the KPA1500 Utility. Go to the Configuration tab in the Utility and select Save Configuration to
complete your tuner's training. Here’s what that will look like.
This completes the setup of the KPA1500 with the Icom IC-7300.