ELECRAFT KPA500 User manual

ELECRAFTKPA500
500-WATT AMPLIFIER
OWNER’S MANUAL
Revision D1, February 27, 2015
Copyright © 2015, Elecraft, Inc.
All Rights Reserved

2
Contents
Introduction...............................................................................................................................................4
Installation ................................................................................................................................................5
Mains Voltage Settings .......................................................................................................................................6
Positioning the Amplifier..................................................................................................................................10
Connections to the Amplifier............................................................................................................................11
Operation ................................................................................................................................................15
Power On...........................................................................................................................................................15
Band Switching.................................................................................................................................................16
Transmitting......................................................................................................................................................16
Using ALC ........................................................................................................................................................17
Monitoring.........................................................................................................................................................18
Remote Operation .............................................................................................................................................18
Fault Conditions................................................................................................................................................19
Menu .................................................................................................................................................................20
Firmware Updates.............................................................................................................................................21
Checking your Firmware Revision ...................................................................................................................21
Wattmeter Calibration Procedure...........................................................................................................22
Specifications..........................................................................................................................................23
Customer Service and Support ...............................................................................................................24
Theory of Operation ...............................................................................................................................25
AUX Connector Interface.......................................................................................................................26
KPA500 AUX Connector Pinout (DE-15 Male)...............................................................................................26
Elecraft KPAK3AUX K3 Cable .......................................................................................................................27
Icom Cable ........................................................................................................................................................27
Yaesu Cable ......................................................................................................................................................28
BCD Interface.........................................................................................................................................28
Elecraft manuals with color images may be downloaded from
www.elecraft.com.

3
WARNING
Dangerous Voltages
Inside the KPA500
Before opening the KPA500 enclosure:
1. Turn off the KPA500 by tapping the front panel ON switch
and wait until the fan stops. (The fan drains the power
supply to a safe voltage.)
2. Place the rear panel rocker switch in off (O) position and
disconnect mains power from the rear panel.
Key to Symbols Abbreviations and Text Styles
Important – read carefully
Operating tip
TEMP Tap switch function (labeled above a switch; press for less than 1/2 second)
PK HOLD Hold switch function (labeled below a switch; press for at least1/2 sec. to
activate)
LED Light Emitting Diode
LCD Liquid Crystal Display
CAUTION
Follow the instructions under a Caution to avoid damage to the equipment.
WARNING
Follow the instructions under a Warning to avoid serious personal injury.

4
Introduction
On behalf of our entire design team, we’d like to thank you for choosing the Elecraft KPA500 amplifier.
The KPA500 offers a unique combination of features. It’s one of the smallest 500-W amplifiers available, yet it
includes a built-in low-noise linear power supply based on a rugged toroidal transformer. It is capable of fully
automatic operation, yet has an alphanumeric display and a full complement of front panel switches for precise
manual control. A comprehensive remote-control command set is also included.
The KPA500 can be used with nearly any transceiver, thanks to its instantaneous RF-based band switching,
advanced protection circuitry, adjustable ALC, and extensive parametric monitoring. It also has inputs that
allow direct band switching from many popular transceivers. T/R is completely noise-free thanks to the use of
PIN-diode switching.
Of course the KPA500 is an ideal companion for the Elecraft K3 transceiver, both physically and electrically.
The K3 can sense whether the amp is in standby or operate mode, then select the appropriate per-band power
settings. This allows you to set up the K3 for “barefoot” operation at one power level on each band, then switch
the amp to operate and set up optimal drive levels for full 500-W output. The K3/KPA500 combination is also
capable of extremely fast break-in, especially when the K3 is placed in QRQ (high-speed CW) mode. The two
are so well-integrated that you can use the per-band switches on the amplifier to change bands at the transceiver.
If you use the KPA500 with both the K3 transceiver and P3 panadapter – our new “K-Line” – you’ll enjoy a
high degree of operating convenience, along with world-class performance and the power to get the job done.
73,
Wayne, N6KR
Eric, WA6HHQ

5
Installation
Installation consists of the following:
Installing fuses and setting the internal transformer taps according to the mains voltages used (page 5).
Positioning the KPA500 to provide for proper cooling (page 10).
Cabling the KPA500 to your other station equipment (page 10).
The KPA500 rear panel is shown in Figure 1. The connectors and controls are described following the figure.
Figure 1. KPA 500 Rear Panel
SO-239 RF connector to your external antenna tuning unit (ATU), antenna or dummy load.
Mains connector for the supplied power cord.
ON/OFF rocker switch that controls mains power to the KPA500.
Fuse block containing mains fuses. The correct fuses must be installed as described under Mains Voltage
Settings on page 6.
AUX connector used for connecting the KPA500 to an Elecraft K3 transceiver using the optional
KPAK3AUX cable or with customer supplied cables for enhanced operation with Yaesu and Icom transceivers
(see AUX Connector Interface on pg 26.)
RCA type connector for PA Key input from the driving transceiver.
RCA type connector for ALC to control the driving transmitter RF level. The output is negative-going from
0 VDC to -12VDC.
RS232 (XVCR)connects the KPA500 to a Kenwood transceiver using a standard 9-pin serial cable. This
connector cannot be used to update KPA500 firmware (see pg 21).
RS232 (PC) connects the KPA500 to your personal computer with a standard 9-pin serial cable. Required for
updating the KPA500 firmware.
Station ground connection. A good station ground with short, direct leads connection each piece of
equipment is important for consistent, reliable operation.
SO-239 RF connector to the driving transceiver.

6
Mains Voltage Settings
Your KPA500 is supplied with the power cable you ordered; either one using the 115VAC connector common
in the USA or one with the common European (Schuko) plug for 200 VAC.
CAUTION
Do not connect mains power to your KPA500 or attempt to turn it on before
setting the fuse block switch and internal jumpers to match your supply
voltage as described below; otherwise you may do extensive damage to your
amplifier.
Fuse Block
Check to ensure the fuse block is set for either 115 VAC or 230 VAC to match your mains voltage. The
current voltage setting is shown in the red window.
If needed, change the fuse block setting as follows:
Position the rocker switch to off (O) and disconnect the mains cord (if connected). Then open the door
covering the fuse block and then carefully pry the red fuse block out of the holder as shown below:
Install the proper fuses in the block. Use two12A fuses for 115V or two 6A fuses for 230V. Use
normal (fast-blow) size 3AG fuses. Both 12A and 6A fuses are supplied in marked envelopes. Note
that the fuse block has a spring contact that presses one end of the fuse outward where it will rest
against an electrical contact when the fuse block is reinstalled in the holder.

7
Replace the fuse block so that the correct mains voltage appears in the window in the cover. The
orientation of the fuse holder sets the proper connections to the power transformer for each mains
voltage range. When replacing the fuse block in the holder squeeze the fuses against the spring
contact so they will slide into the holder.
Be sure the fuse block is fully seated in the holder as shown below before trying to close the door.
You may feel a lot of resistance just before it is fully seated as the fuses reach the contacts inside the
holder. That is normal.

8
Close the cover and be sure the fuse block is oriented correctly showing the proper mains voltage
as shown below:
If you are setting up your just received factory-built KPA500 or a just assembled kit, the transformer tap
is already set for either 116 to 126V or 231 to 250 V. Go directly to Power Supply Voltage Test on pg
10 to determine whether you need to adjust the tap as described below. If you are reinstalling the
amplifier in a new location and are unsure of the tap setting, open the top cover to verify that the correct
tap is set before applying mains power.
Power Supply Transformer Tap
WARNING
If the KPA500 has been previously turned on, tap the front panel ON switch to turn
it on, and then tap it again to turn the unit off and wait for the fan to stop before
removing mains power. This drains the power supply to a safe voltage. When the fan
stops, remove mains power at the rear panel. (Units shipped from the factory are safe
to open without turning them on first).

9
Remove the 14 screws securing the KPA500 top cover as shown below. Do not remove the screw
indicated. It is part of the safety interlock switch mechanism. Lift the top cover off.
Three taps are provided via red, green and yellow wires. Choose the tap according to the actual
mains voltage at the outlet you plan to use for the KPA500. If you cannot measure your mains
voltage, use the yellow tap.
115V Nominal Mains TAP 230V Nominal Mains
95V to 105V GREEN 190V to 210V
106V to 115V RED 211V to 230V
116V to 125V YELLOW 231V to 250V
Be sure to place the unused taps side-by-side on the terminals at the back panel as shown. Do not
leave them floating loose inside the unit.
Replace the top cover before proceeding. An interlock switch prevents operating the amplifier with
the top cover removed. Until you complete the Power Supply Voltage Test on the next page, only
install the corner screws to hold the cover and the interlock switch closed.

10
Power Supply Voltage Test
Test the power supply voltage output as follows:
The top cover must be in place on the KPA500 to activate the interlock
switch before you can test the supply voltage output.
Connect the mains supply cable to on the rear panel and plug the cable into the mains outlet.
Position the rear-panel power switch to On (I).
Tap the front panel ON switch ( on Figure 5). The LCD should light.
Tap the HV switch ( on Figure 2) and note the voltage displayed on the LCD. It must be between
65 and 85 volts. If it is outside of this range, immediately tap the ON switch to turn the KPA500 off,
wait until the fan stops completely, and then position the rear panel power switch to off (O). The fan
runs to discharge the power supply to a safe level. Do not disconnect mains power or position the
rear panel rocker switch to off until the fan stops.
Open the top cover and select a different transformer tap. If the voltage was too low, select a tap
further up the list in the above table. If the voltage was too high, select a tap further down the table.
The red FAULT LED ( on Figure 5) will light when you tap the ON switch to
protect your KPA500 if the power supply voltage is too far above the upper limit.
Use a power transformer tap lower on the above table and retry the test.
After you have confirmed the correct transformer tap, be sure to replace all 14 screws in the
top cover.
Positioning the Amplifier
Provide at least 2 inches (5 cm) clearance behind the fan and a 1 inch (2.5 cm) above the amplifier for normal
cooling air flow.
A clearance above the amplifier of less than 1 inch may be used when the amplifier is not subjected to high-
duty-cycle operation at full power (e.g. digital modes such as RTTY and PSK or contesting.) Higher duty-cycle
modes will cause the amplifier temperature to increase, resulting in higher speed cooling fan operation. For
those cases we recommend maintaining at least 1 inch (2.5 cm) clearance for cooling air above the amplifier.

11
Connections to the Amplifier
Always turn the amplifier off using the rear panel switch ( in Figure 1) before attaching
or removing cables.
The KPA500 may be used with the Elecraft K3, K2 or any HF/6 meter transmitter that has a PA Key output
meeting the requirements shown under note 4.below. In interconnections the transceiver are shown in Figure 2.
The driving transceiver must provide up to 40 watts of RF drive for full output and the output power must be
adjustable as described under Transmitting on pg 16.
The optional KPAK3AUX cable provides closer integration with the K3 by sharing band information between
the KPA500 and the transceiver (see Figure 3). The KPAK3AUX cable provides all the operational features
described under Operation, including coordinated band-switching (pg 16). The KPAK3AUX cable includes the
PA Key line. If you need access to this line so that other equipment can control the amplifier, you can install the
Key Line interrupter supplied with your KPAK3AUX cable set and use a separate key line as shown in Figure 4.
You must use the Key Line Interrupter when using a separate key line with the
KPAK3AUX cable set. Otherwise any external equipment inserted into the key line will not
be able to inhibit the amplifier.
You can make cables for use with Yaesu and Icom transceivers that also provide closer integration with the
KPA500. For details of those cables and the KPAK3AUX cable set see AUX Connector Interface on page 26.
NOTE
1. Connect your station ground to the GND thumbscrew . A good station ground is important for safety
and to minimize local radio frequency interference (RFI).
2. Attach the RF INPUT to the output of your driving transceiver or transmitter using a 50 ohm coaxial
cable with a PL-259 male connector on the KPA500 end.
3. Attach the RF OUTPUT to a suitable load with an SWR of less than 1.5:1. A dummy load is strongly
recommended for initial testing.
4. The driving transmitter must ground the PA KEY line circuit during transmit while sinking up to 1 mA.
If the transmitter Key Output is not a contact closure or equivalent, it must be at a level between +4 and
+16 VDC during receive. (Compatible with all known transmitters. No key line buffer required.)

12
Figure 2. Basic Cabling Diagram for Any Transceiver.

13
Figure 3. K3 Enhanced Cabling Using KPAK3AUX Cable.

14
Figure 4. K3 Enhanced Cabling Using KPAK3AUX Cable and Separate Key Line.

15
Operation
Power On
1. Ensure a suitable 50 ohm load is attached to the RF OUTPUT connector on the rear panel (Figure
1, ). A dummy load is recommended for initial tests.
2. Enable the power supply by pressing the rear panel rocker switch (Figure 1, ) to the On (I)
position.
Switches with a legend above and below the pushbutton have two
functions. Tap (press briefly) to activate the function labeled above a switch.
Hold to activate the function labeled below the switch. In the text, tap
functions are shown like this: TEMP . An example of a hold function is PK
HOLD .
Figure 5. KPA500 Front Panel.
3. Tap the ON switch . The LCD and STBY LED should light. When you tap the ON switch again to
turn the amplifier off you will hear the fan run. This is done to bleed off the 60V power supply voltage.
The fan stops when the voltage reaches a safe level so, if you are preparing to open the KPA500 cabinet
for any reason, be sure to allow the fan to run until it stops before switching off power with the rear
panel rocker switch or unplugging the KPA500 from mains power.
If at any time the FAULT LED lights, refer to Fault Conditions, pg. 18.

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 200 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)

17
3. Increase the drive power and confirm that the SWR bargraph indicates less than 1.5 while the
output indicated by the POWER (W) LEDs increases. For ease in reading the critical SWR levels,
the SWR LEDs are green from 1 to 1.5. The 1.5 to 2.1 SWR LEDs are yellow and the LEDs for
SWRs above 2.1 are red. Up to 40 watts of drive may be required to produce the full 500 watts
output from the KPA500. It is normal to hear hum from the power transformer. The hum level
will increase with the power level. During heavy use, you may hear audible clicking sounds,
particularly as amplifier components cool after transmitting. This is normal. It does not indicate
that the amplifier is being overly stressed.
NOTE
The KPA500 operates to full specifications when the HV under full load is
between 60V and 85V as shown on the LCD (Tap HV to display the voltage
under CW “key down” conditions at full power). The maximum voltage is set
using transformer taps as described on pg. 9.
The KPA500 will operate with reduced performance at voltages as low as 40V.
When the voltage is less than 60V the maximum output power may be less than
500W and distortion products will increase.
The KPA500 will fault and automatically switch off-line if the supply voltage
exceeds 90V to protect the power supply components. If your AC (Mains) line
regulation is poor, such that your supply voltage is at least 85V in standby but
sags below 60V during full power output, you may need to reduce the input drive
to limit the power output to less than 500 watts.
4. When driving the KPA500 with an Elecraft K3, use the K3’s per-band power control to set the
amplifier output just below the desired peak output on each band. Do not rely on ALC to control
the power output (see Using ALC, pg 17). At the K3, set CONFIG:POWER SET to Per Band. See
Per-Band Power Control in your K3 Owner’s manual for further details.
If you use the AUX cable interface between the K3 and KPA500 (pg 26), the KPA500
will send the OPER/STBY status to the K3. You can then set two per-band power levels at
the K3: one to drive the KPA500 when it is in OPER mode and another for pass-through
transmitting when the KPA500 is in STBY. The K3 will automatically furnish your preset
power levels as you switch the KPA500 between OPER and STBY.
Using ALC
Automatic Level Control (ALC) is a useful safety mechanism, but never use ALC as the principle power
control. Doing so causes many of the unwanted transmit dynamics you often hear on the air including excessive
intermodulation distortion (IMD) and clicks. Instead, set your transmitter power output correctly as described
under Transmitting (pg 16) and adjust the ALC so it does not affect output power in normal operation. To do
this, drive the KPA500 to the desired output. Adjust ALC THR in the menu (pg 20) until power just starts to drop
and then set ALC THR above this setting so it does not affect the output power in normal operation.
The Elecraft K3 ALC intentionally has a slow attack and much slower decay to avoid adding more distortion or
dynamics problems than necessary. However, not all of the negative effects of ALC action can be avoided. It is
still best to set the ALC threshold and then adjust the drive to avoid ALC action in normal operation.

18
Monitoring
KPA500 operation is monitored by the LEDs , and and reported in text on the LCD.
LEDs
The SWR of the load and the output power are displayed on LED bar graphs. The bar graphs are color-coded:
green for normal operating range, yellow for marginal levels and red for excessive levels. Excessive levels may
trigger a fault and shut the KPA500 off (see Fault Conditions below). An LED lights if a fault condition
occurs. Also two LEDs indicate whether the amplifier is in standby (STBY) or operating (OPER) mode.
LCD
Normally the LCD displays the band currently selected. The four switches around the LCD select other
information to be displayed on the screen and the behavior of the LEDs. Note that these switches have both tap
and hold functions (pg 3). Repeat the tap or hold action to return the LCD to the band display.
HV displays the PA voltage on the LCD. Must be between 65 and 85 V when the KPA500 is in
STBY.
CURRENT displays the PA current on the LCD. Must never exceed 20 A.
TEMP displays the heat sink temperature on the LCD. Must be less than 90C.
PWR displays the output power numerically on the LCD. Must not exceed 650 W.
MENU displays the menu system (see pg. 20).
EDIT enables editing menu parameters (see pg. 20).
PK HOLD toggles the peak power output display on the bar graph. When enabled, the LED
corresponding to the peak power output remains lighted for one second.
SWR displays the load SWR numerically on the LCD.
Remote Operation
The KPA500 can be controlled remotely using a personal computer connected to the RS232 port. A basic
remote operating capability is built into the KPA500 Utility program (see pg 21). For those who may wish to
develop their own software, a Command Reference Manual is available on the Elecraft web site.
(www.elecraft.com).

19
Fault Conditions
The FAULT indicator lights and the speaker sounds to indicate a fault condition has occurred. To avoid
unnecessarily interrupting amplification because of moderately abnormal conditions, there are two levels of
faults that may occur, attenuator faults and hard faults.
Attenuator Faults
Relatively minor faults such as excessive reflected power cause an internal 3dB attenuator to be switched into
the RF path that reduces the output to protect the KPA500. When an attenuator fault occurs, the FAULT LED
blinks and the cause is displayed on the LCD for about 1 second. The KPA500 tests the condition at intervals
and will return to normal operation automatically after the cause of the fault is removed. The interval between
tests is set with the ATTEN REL menu (pg 20). If the fault persists over time or if it is severe enough, a hard
fault will occur.
Hard Faults
Hard faults are those that require switching the KPA500 to STBY to protect it, such as conditions of extremely
high reflected power or high drive power, or because a critical component such as a power supply has failed.
When a Hard Fault occurs, the cause of the fault is displayed on the LCD. When the condition has been
corrected, tap the OP/STBY switch to return the KPA500 to normal operation, or tap the INFO switch to return
the KPA500 to STBY mode.
LCD Display Fault Fault Type Fault No.1
GAIN ERR Excessive overall amplifier gain. Hard 15
HI CURR Excessive power amplifier current.2Attenuator→Hard 2
HI TEMP Power amplifier temperature over limit.2 Hard 4
PWRIN HI Excessive driving power. Attenuator→Hard 6
PA DISS Power amplifiers are dissipating excessive power. 2 Hard 11
POUT HI Excessive power output. Attenuator→Hard 12
REFL HI Excessive reflected power (high SWR). Attenuator→Hard 9
60V HIGH 60 volt supply over limit (see Positioning the Amplifier, pg 10). Hard 8
60V FAIL 60 volt supply failure. Requires cycling KPA500 mains power after it
is corrected.3Hard 13
270V ERR 270 volt supply failure. Requires cycling KPA500 mains power after it
is corrected.3Hard 14
N/A Communication failure between KPA500 and K3. N/A 0
NOTES:
1. When the KPA500 is used with the Elecraft K3 transceiver, and the optional K3 interface cable
(see Elecraft KPAK3AUX K3 Cable ,pg 27) is used to connect the K3 to the KPA500, these
numbers will be displayed on the K3’s LCD briefly if a hard fault occurs.
2. These faults are commonly caused by excessive power output or excessive reflected power.
3. An open KPA500 top cover interlock switch will cause this fault. See pg 9. If you have just built
your KPA500 from a kit, ensure the interlock switch actuator is assembled exactly as shown under
Top Cover and Side Handle in the Assembly Manual. Leaving any parts out will cause the actuator
to be too short to operate the interlock switch properly.

20
Menu
Holding MENU enables the menu function to allow the following parameters to be set. With the menu
function enabled, the MENU, EDIT and switches next to the and symbols all respond to a simple tap. Use
them to scroll through the menu items. Tap EDIT and then the and switches to select the parameter and
tap MENU again to save the parameter. Tap MENU to exit the menu.
To reset all the parameters to the default value, press and hold the EDIT switch while tapping the ON switch to
turn the KPA500 on.
Menu Entry Default Description
ALC THR 210 ALC Threshold Adjustment: 0to 210. See Using ALC on pg 17.
ATTN REL 3 Attenuator Release Time: 1.4 – 5 seconds.
BAND CHG NOR NOR: OPER/STBY status the same after band change.
STBY: Switches amp to standby after band change.
DEMO NOR Factory Use Only.
FAN CTL NOR
Sets minimum fan speed.
NOR: fan is off when not needed.
1 to 6: selects various minimum speeds. Fan speed increases automatically as needed for
cooling.
FW REV Displays firmware revision.
INHIB IN DISABLE ENABLE allows the amplifier operation to be inhibited (won’t amplify) when a logic low is
applied to pin 11 of the AUX Connector (see pg 26). When amplification is inhibited, an
underscore instead of the asterisk appears on the left end of the LCD display.
LCD ADJ 30 LCD Contrast Adjustment.
LCD BRT 6 LCD Backlight Brightness. Use DAY in bright sunlight. 2 to 8 for indoor lighting.
LED BRT 6 LED Brightness.
PWR ADJ 100 Per-Band Wattmeter Calibration, range 80 to 120. These are percentages of the measured
value.See Wattmeter Calibration Procedure on page 22.
PWR ON STBY STBY: Amp is in standby mode when first turned on.
OPER: Amp is in operate mode when first turned on.
RADIO K3
Specifies driving transceiver interface:
K3: Allows use of Auxbus interface which allows the KPA500 band switches to change bands
on the K3; sends KPA500 mode to the K3 so the K3 can automatically select correct drive
power when the KPA500 is in OPER (see 16); reports KPA500 faults to K3.
BCD: Signals provided by Yaesu transceivers.
ANALOG: Signals provided by Icom transceivers. Note that Icom transceivers do not identify
WARC bands, but KPA500 frequency sensing will switch the KPA500 to the correct band
upon transmit.
SERIAL: Kenwood/Elecraft compatible interface using RS232X port. If transceiver is in split
mode, the transmit frequency will select proper band at KPA500.
RS232 P 38400 PC Serial Port Speed: 4800, 9600, 19200, 38400 bps
RS232 X 4800 Transceiver Serial Port Speed: 4800, 9600, 19200, 38400 bps. Set RADIO to SERIAL.
SER NUM Displays the unit serial number.
SER POLL N/A
ON: Enables KPA500 polling of the transceiver for frequency band via RS232X port (e.g. for
Kenwood/Elecraft compatible interface). Note: RADIO menu entry must be set to SERIAL.
OFF: Other device (PC, etc.) polls transceiver for frequency band.
N/A: RADIO menu not set to SERIAL.
SPEAKER ON Speaker (fault annunciator) ON or OFF.
TR TIME 0 QSK Delay Time: 0to 50 ms; Slows T/R release time for transceivers with poor transmit
timing characteristics.