Edit Configuration

Some KPA1500 configuration values may be set individually per band. The dialogs also provide an easy way to configure the same value for all bands.

Changes are not applied until one of the Apply or OK buttons are pressed. Pending changes from all tabs are written at once when Apply or OK is selected. OK saves changes and closes the dialog; Apply saves changes and leaves the dialog open.

Antenna Enable

Configure the enabled and preferred antenna connectors.

Enabled antennas are available for use on a given band. Disabled antennas are skipped by successive presses of the KPA1500 ANT button.

The Preferred antenna is selected when your KPA1500 changes to the indicated band.

Antenna Enable image

ATU SWR Thresholds

ATU SWR thresholds may be set individually by band, or to the same value for all bands. When SWR thresholds are the same for all bands and Band "All" is selected, that value is shown in SWR Thresholds. When SWR thresholds differ from band to band and Band "All" is selected, a blank is shown in SWR Thresholds.

The No Match SWR threshold is the same for all bands.

Retune

Choose the SWR above which your KPA1500 should retune (if ATU HiSWR Retune is enabled). If this threshold is set too low, the ATU may repeatedly retune on each transmission. The default is 1.8 to 1

Bypass

The KPA1500 ATU tuning algorithm first measures the SWR of the antenna with the ATU bypassed. If the antenna's SWR is "good enough", the preferred ATU setting is to bypass all inductors and capacitors. This threshold is used to choose your notion of "good enough".

With ATU MODE IN, the ATU setting can be "bypassed" for some frequencies and "not bypassed" on other frequencies. For example, my 20 meter antenna SWR is not flat across the band. At lower frequencies, SWR is low and my KPA1500 ATU setting is "bypassed". The antenna's SWR rises further up the band. On these frequencies the ATU matches the amplifier's impedance to the antenna. I don't have to think about which frequencies require "bypassed" or "not bypassed", because the antenna tuner has stored them during the "tuner training session" I performed initially. ATU relay settings are the same in "ATU MODE BYP" as they are when ATU MODE is "IN" and the ATU setting is "bypassed".

Stop Search

When an ATU HiSWR Retune is started, the ATU evaluates a few previously stored ATU settings for the current and nearby frequencies. The search stops when a ATU setting is "good enough". This threshold is your notion of "good enough".

A "full search" tune, started with an ATU TUNE button press, always searches for the lowest SWR.

No Match

If an ATU search tune completes with an SWR higher than the No Match SWR threshold, a NO MATCH fault occurs, which switches the amplifier to STBY.

The intended use of this threshold is to inhibit amplification into a poorly matched ATU setting, such as a disconnected antenna connector. You may reset this fault and continue to transmit, but reduce power to avoid encountering another fault threshold, such as high reflected power.

The No Match SWR threshold is the same for all bands.

SWR Threshold image

ATU HiSWR Retune

Your KPA1500 can store several different ATU settings for each frequency. If you have several antennas on a given band, or an antenna whose impedance changes because of weather or direction, you might have several different ATU settings for the same frequency and antenna connector. Normally ATU HiSWR Retune is turned off on bands with just one antenna. ATU HiSWR Retune can be used to select an ATU setting whenever SWR rises over the SWR Retune Threshold. ATU HiSWR Retune does not start a "full search" tune; it selects the best of a few predetermined ATU settings. Retune search requires constant carrier from the exciter, but it evaluates just a few predetermined ATU settings and should be quick. This ATU HiSWR retune search stops if an ATU setting is found that provides an SWR less than the SWR STOP threshold.

Press the ATU TUNE button for a "full search" tune.

ATU tuning is done with exciter power. The power amplifier is bypassed during ATU TUNE.

ATUHiSWRRetune image

ATU Mode Switch

You may prefer one ATU IN/BYP setting for all bands and antennas.

Alternatively, you may prefer to keep the ATU bypassed for certain antennas, such as a SteppIR or an antenna with a separate antenna tuner.

ATU Mode Switch image

ATU Settings/Bin

The KPA1500 ATU has storage enough for 31 distinct ATU settings per frequency segment (also called a "bin"). This is intended to provide enough space for different ATU settings for externally switched antennas, or for stations whose antennas may have different impedance depending on weather or antenna direction. If you have fewer antennas, it may be preferable to store fewer settings, related to the number of antennas available on each band. For example, I have only one 6 meter antenna, and the ATU settings are stable. However on 20 meters I may use a beam, or a vertical, or a wire antenna. I want room a few more ATU settings in each bin. The ATU HiSWR retune capability may be used to select the best of a few already-determined ATU settings. ATU Settings Per Bin is new in KPA1500 firmware version 01.54.

ATU Settings Per Bin image

ATU XCVR Key

Your KPA1500 requires a constant carrier from your K3/K3S during ATU HiSWR retune and ATU TUNE operations. You may choose to control this manually, by starting an ATU TUNE and then press a TUNE button to provide TUNE POWER. When the ATU tuning operation completes, tap the K3 TUNE button again to stop TUNE POWER.

ATU tuning requires fewer button presses if the KPA1500 signals the K3 to start and stop TUNE POWER when needed.

You may also choose to connect a keying cable from the tip of the 3.5mm KPA1500 TUNE connector to your exciter's straight key connect or for this purpose. This transceiver keying mechanism is not affected by the ATU XCVR Key setting.

AtuXcvrKey image

Network

Used for TCP/IP configuration. The KPA1500's network addresses are often supplied by a DHCP server on your network (my home router provides this capability). This page shows the IP address, Subnet Mask, and Gateway address assigned by the DHCP server. For static IP addresses, uncheck "DHCP", and provide the static IP, mask, and gateway IP addresses in dotted octet format.

The MAC is the Media Access Control address assigned uniquely to each KPA1500. This address is provided by the microcontroller manufacturer and may not be changed.

These concepts are described in Wikipedia, search for "IP address", "MAC address", "gateway address", and "subnet mask".

The TCP port number assigned to the KPA1500 TCP command server defaults to 1500. You may change it here. A remote access program will need the IP address and port number for connection.

You may need to leave the Edit Configuration dialog and reload it to observe the IP addresses when you enable DHCP.

Network image

Program Function Keys

This page is used to store a sequence of KPA1500 commands that are executed when the PF1 or PF2 button is pressed. PF1 is the HOLD function of the MODE pushbutton. PF2 is the HOLD function of the ANTENNA pushbutton. See the KPA1500 Programming Reference ^PF for command format. The command strings may be up to 127 characters long. PF keys are new in firmware version 01.54.

PF key image

A "power on banner" is briefly displayed when your KPA1500 is switched on.

Banner image