Operate

This page may be used to observe amplifier status and make adjustments. The KPA1500 Front Panel buttons, LCD, and LEDs are shown.

KPA1500 Buttons that may be tapped or held are shown as two buttons on this page. For example, the ATU TUNE button on the KPA1500 Front Panel is either tapped for ATU TUNE or held for an ATU MODE change. On this screen two different buttons are shown.

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Forward Power

The forward power, in Watts, measured between the KPA1500 power amplifier and its ATU. When the KPA1500 is in STBY, this is the power from your transmitter.

Reflected Power

The reflected power, in Watts, measured between the KPA1500 power amplifier and its ATU.

SWR

SWR as seen by the power amplifier, derived from the forward and reflected power measurements above. The SWR the power amplifier "sees", which may differ from the Antenna's SWR.

Bypass SWR

SWR measured when the ATU was bypassed, during ATU TUNE. This is the SWR of the antenna, captured during a search ATU tune.

Frequency

The frequency, in kHz, counted by the KPA1500's transmit frequency counter. This is used for band selection and to locate ATU settings.

Input Power

Transceiver power, in Watts, measured with a coupler at the power amplifier input. The input power coupler is bypassed when the amplifier is in STBY, then the transceiver power is displayed as forward power.

PA Current

Power Amplifier (PA) current, in Amperes.

Temperature

The temperature of the PA heat sink, in degrees Centigrade. Cooling fan speed is varied depending on this measurement.

Mode

The amplifier's MODE is "Operate" when the amplifier is adding gain, and "Standby" when the PA is bypassed, connecting the KPA1500 input RF connector to the input of the KPA1500 ATU.

The PA is temporarily bypassed while relays are changed during band switch and ATU tuning. MODE and the OPER and STBY LEDs are not changed during this process.

Antenna

Selects one of the two KPA1500 antenna connectors. Disabled antenna connectors may not be selected.

ATU Tune

Click the KPA1500 Utility Tune button or tap the KPA1500 front panel ATU TUNE button to start a "full tune". Click the KPA1500 Utility Tune button or tap the KPA1500 ATU TUNE button again to interrupt tuning.

ATU Mode

When ATU MODE is "IN", the Antenna Tuner can help to match the power amplifier impedance to the antenna impedance.

When ATU MODE is "IN", and the antenna tuner determines that the ATU bypassed setting is adequate for the current antenna, both ATU IN and ATU BYP are illuminated.

When ATU MODE is "BYP", the Antenna Tuner is bypassed.

ATU MODE is independent of MODE OPER/STBY; the ATU may be used without the KPA1500 power amplifier

Tapping the ATU TUNE button changes ATU MODE to IN.

Power

The checkbox at the bottom right turns the KPA1500 power on or off.

Advanced Mode Operate Page

When Advanced Mode is selected, additional items are shown:

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PA Voltage

The measured voltage of the 52V supply. Shown when Advanced Mode is selected.

Dissipated Power

Dissipated power is the difference between DC input power (PA Current times PA voltage) and the output power RF in Watts. This difference is dissipated as heat. Dissipated power is a measure of the amplifier's efficiency. Shown when Advanced Mode is selected.

Efficiency

Efficiency is the ratio of RF output power to DC input power (PA current * PA voltage). Shown when Advanced Mode is selected.

Capacitance pF

Eight capacitors, ranging from 8 to 1360 picoFarads, may be used in any combination. Normally the KPA1500 selects capacitors during an ATU tune operation. You may manually select one or more of the check boxes to choose individual capacitors, or type the desired total capacitance in picoFarads into the text box. The KPA1500 Utility chooses the capacitors that result in the highest available capacitance that does not exceed your requested capacitance when you "leave" the text box by pressing the TAB key or click another area with the mouse. You may position the mouse cursor over the up or down arrow at the right edge of the text box and left click to "nudge" the capacitance up or down. Hold the left mouse button while over the up or down arrows to rapidly "spin" through the available values.

Note: when bypassed, firmware releases all capacitor relays, all inductor relays and the side relay to reduce power consumption. When the bypass relay is changed to "not bypassed", the last used L, C, and side relay settings are restored.

Inductance nH

The KPA1500 ATU has seven inductors, ranging from 50 to 4400 nanoHenries. See the section above on capacitors; the inductor group works the same way.

Note: when bypassed, firmware releases all capacitor relays, all inductor relays and the SIDE relay to reduce power consumption. When the bypass relay is changed to "not bypassed", the last used L, C, and SIDE relay settings are restored.

Caps on TX Side

Your KPA1500 ATU uses a bank of capacitors and a bank of inductors arranged in a switched L network. The capacitors may be switched to shunt either the transmitter or the antenna side of the series inductance. Generally, the capacitor should shunt the higher of the transmitter or antenna impedances. Your KPA1500 determines the appropriate setting during TUNE.

ATU Store

Saves the current ATU setting for subsequent recall. This might be used if you "tweak" the tuner settings and wish to save the adjusted value.