160m – 6m
Bands
2012
Introduced
Frequency1.8-54 MHz, continuous
Bands160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m
PowerNot a transmitter; rated by matching capability and power handling. Typical matching range is about 10:1 SWR at 600 W on 3-30 MHz (5 to 500 ohms), tightening to 3:1 SWR at up to 1000 W (16 to 150 ohms). On 160 m (1.8-2 MHz) it matches about 5:1 on the low-impedance side (10:1 high-impedance) at 600 W; on 6 m (30-60 MHz) up to 5:1 at 500 W. The power rating is ICAS (equal time transmit and receive, 5 minutes maximum at full power). Autotune works from about 7 to 100 W, with 20 to 100 W recommended for accuracy; a stored memory can be recalled at lower power.
ModesAll modes (a passive network that matches whatever the transmitter passes through it)
Weight2.1 kg (4.6 lb)
Year2012
Connectors
xmtr rf inXMTR SO-239, 50 ohm: RF input from the transceiver or amplifier
ant 1ANT 1 SO-239 antenna output
ant 2ANT 2 SO-239 antenna output
ant 3ANT 3 SO-239 antenna output (the tuner auto-selects the antenna assigned to each band)
amp controlAMP CONTROL connector for KPA500 integration (E850463 aux cable: band data and PA keying)
dataDATA 3.5 mm TRS jack for transceiver band data (for example Kenwood serial via the CBL-KENSER500 cable)
serialRS-232 serial port for the KAT500 Utility and firmware updates; Elecraft supplies a USB-to-serial (KXUSB) or serial (KXSER) cable
dc power11-15 VDC via a 2.1 mm coaxial barrel (center positive), 1.0 A maximum (200 mA typical)
groundGND wing-nut terminal for station ground
power req11 to 15 VDC at 1.0 A maximum (200 mA typical), through a 2.1 mm coaxial barrel (center positive). No mains connection.
Fully automatic antenna tuner covering 1.8 to 54 MHz continuously (160 through 6 meters), built around a relay-switched L-network of toroidal inductors and switched capacitors with no motorized parts Four SO-239 jacks: a transmitter input (XMTR) and three antenna outputs (ANT 1/2/3); the tuner automatically selects the antenna assigned to each band Stores L and C tuning solutions per frequency segment and per antenna, so it recalls a match in milliseconds on band or frequency changes instead of re-tuning Typical matching range about 10:1 SWR at 600 W on 3-30 MHz (5 to 500 ohms), tightening to 3:1 at up to 1000 W (16 to 150 ohms); about 5:1 low-impedance on 160 m; up to 5:1 at 500 W on 6 m; power rating is ICAS (5 minutes maximum at full power) Autotune works from about 7 to 100 W (20 to 100 W recommended for accuracy); a stored memory can be recalled at lower power Works with any transceiver or amplifier: Standard mode uses RF sensing and an internal frequency counter, Intermediate mode reads BCD band data, and Enhanced mode uses Elecraft serial band data Integrates with the K3/K3S transceiver and the KPA500 amplifier through the AMP CONTROL connector and the E850463 aux cable, sharing band selection and PA keying Rear-panel DATA 3.5 mm TRS jack for transceiver band data (for example Kenwood serial through the CBL-KENSER500 cable), plus an RS-232 serial port for the KAT500 Utility and firmware (Elecraft supplies a USB-to-serial KXUSB or serial KXSER cable) Self-protection circuits guard against switching high-power RF or matching loads outside the tuning range, and a built-in static-bleed resistor drains antenna static Front-panel SWR and status display, with remote control and monitoring through the shared KAT/KPA Utility software Powered from 11 to 15 VDC at 1.0 A maximum (200 mA typical) through a 2.1 mm coaxial barrel; no mains connection Low-profile enclosure 1.5 x 10.8 x 10.0 in (3.8 x 27.4 x 25.4 cm) at 4.6 lb (2.1 kg), matching the K3S footprint so it stacks in the K-line Uses the same tuning topology and algorithms as the internal autotuners in the K3S, KX3 and KX2 Sold as a no-soldering kit (KAT500-K) or factory-assembled (KAT500-F) at the same price, with field-updatable firmware
Strengths

Handles three antennas with automatic per-band selection and stores tuning solutions per segment and per antenna, so band and frequency changes recall a match in milliseconds with no tune button. The roughly 10:1 range at 600 watts forgives real-world antennas, it works with almost any transceiver or amplifier through RF sensing or band data, and it is low and light enough to stack with the K3S. Self-protection and a static-bleed resistor are built in.

Weaknesses

It costs more than typical 500-watt-class autotuners. The full 1000-watt rating narrows the matching range to 3:1, and the ICAS power rating limits continuous full-power transmit to five minutes. The relays click during a tune, so the speed advantage is in recalling stored memories rather than in silent operation.

Verdict

The KAT500 is a 500-watt-class automatic antenna tuner covering 160 through 6 meters with three switched antenna ports and per-segment, per-antenna tuning memories. It is built to sit beside the KPA500 amplifier and K3S transceiver but works with most radios and amplifiers through RF sensing or band data. Stations heading to full legal limit can instead use the KPA1500, which has a tuner built in.

The Elecraft KAT500 is a fully automatic antenna tuner and three-way antenna switch covering 1.8 to 54 MHz continuously, from 160 through 6 meters. It uses a relay-switched L-network of toroidal inductors and switched capacitors, with no motorized parts, and stores the inductance and capacitance settings for lowest SWR in memory per frequency segment and per antenna. Once a solution is stored, the tuner recalls it in milliseconds as the operating frequency moves, so band and frequency changes need no separate tune step.

It has four SO-239 jacks: a transmitter input and three antenna outputs, and it automatically selects the antenna assigned to each band. The typical matching range is about 10:1 SWR at 600 watts on the 3 to 30 MHz bands, tightening to 3:1 at up to 1000 watts, with a narrower range on 160 and 6 meters; the power rating is ICAS, limiting continuous full-power transmit to five minutes. Autotune works from about 7 to 100 watts. The tuner runs from 11 to 15 VDC through a coaxial barrel jack and draws well under an amp, and a static-bleed resistor and self-protection circuits are built in.

The KAT500 is designed to work with the K3S transceiver and the KPA500 amplifier through an AMP CONTROL connector and aux cable, but RF sensing, BCD band data, or Elecraft serial data let it work with most other transceivers and amplifiers. Its enclosure matches the K3S footprint and is only 1.5 inches tall, so it stacks in the K-line. Stations heading to full legal limit can instead use the KPA1500, which builds the tuner into the amplifier.