Elecraft KPA1500
$$$$$
| Frequency | 1.8-29.7 MHz (all amateur bands, 160-10 m), 50-54.2 MHz (6 m) |
| Bands | 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m |
| TX power | 1500 W (1500 W PEP output on CW, SSB and data from 50 to 60 W of typical drive. A pair of LDMOS transistors run from a 50 V high-current supply, about 50% efficient (varies by band). Rated 100% ICAS for full-duty digital modes (FM, RTTY, FT8, JT65 and similar); for continuous key-down the limit is 5 minutes transmit then at least 5 minutes receive on 1.8-30 MHz, and 50 seconds transmit / 50 seconds receive on 50 MHz.) |
| Modes | CW, SSB, Data (FT8/RTTY/JT65 and similar), AM/FM (within the rating and duty cycle) |
| Weight | 10 kg (22 lb) |
| Year | 2018 |
| rf input | SO-239, 50 ohm (PL-259 cable from the transceiver); at least 50 W drive (50-60 W typical) for 1500 W |
| ant 1 | SO-239 antenna output 1 (chosen with the front-panel ANTENNA switch) |
| ant 2 | SO-239 antenna output 2 (per-antenna ATU memories) |
| key in | RCA KEY IN: grounded on transmit (sinks up to 5 mA); if not a contact closure, must sit at +4 to +16 VDC on receive |
| alc out | ALC output, negative-going and adjustable, for transceivers that use ALC |
| pure signal | Low-level transmit sample output (about -60 dBm, rising to +10 dBm at 1500 W) from the internal directional coupler, for Pure Signal closed-loop pre-distortion |
| aux | AUX DE-15 (15-pin male): KPAK3AUX Enhanced Mode with K3/K3S (band data, antenna select, ATU memory recall); can also command the amp on/off |
| xcvr serial | XCVR SERIAL 3.5 mm TRS jack: serial band/frequency data for Elecraft KX3/KX2, Kenwood and other rigs (up to 38400 bps) |
| tune | TUNE 3.5 mm TRS jack: Icom remote-tuner control and CW-key tune start |
| usb | USB-B: KPA1500 Utility software and firmware updates |
| ethernet | RJ45 Ethernet: local and remote network operation |
| rem | REM: 12 VDC input for remote power on/off (for example from a K3S/K3 12 V DC OUT) |
| ground | GND terminal for station ground |
| hv supply | HV SUPPLY: Anderson PowerPole high-voltage (50 V) cable from the separate power supply |
| control | CONTROL: 15-pin control cable to the power supply |
| ac mains | Power-supply AC inlet: 200-250 VAC, 50/60 Hz, up to 20 A, with a NEMA 6-20 molded plug (US) |
| power req | Two-cabinet design. A separate switching power supply feeds the RF deck through an Anderson PowerPole high-voltage (50 V) cable and a 15-pin control cable. The power supply runs on 200-250 VAC, 50/60 Hz, up to 20 A and ships with a NEMA 6-20 molded plug (US), so it needs a dedicated 240 V / 20 A circuit. There is no 120 V option. |
Makes the full 1500-watt legal limit from only 50 to 60 watts of drive and includes a built-in automatic tuner with two antenna jacks, so the amplifier and antenna matching are handled in one system. LDMOS finals and a 100% ICAS rating suit modern high-duty digital operating, RF-sensing band switching follows almost any radio, and USB plus Ethernet allow full remote control. Transmit/receive switching is silent.
It is expensive, at flagship-transceiver money for the amplifier alone. The power supply is a separate cabinet and needs a dedicated 240 V / 20 A circuit (NEMA 6-20), which is real installation work. Continuous key-down on HF is limited to 5 minutes before a 5-minute cool-down, and solid-state protection folds back power where a tube amplifier might tolerate a brief mismatch.
The KPA1500 is Elecraft's 1500-watt solid-state linear amplifier with a built-in automatic antenna tuner, covering 160 through 10 meters plus 6 meters. It produces full legal-limit output from 50 to 60 watts of drive, switches bands automatically with almost any transceiver, and supports remote operation over Ethernet. It needs a dedicated 240 V circuit and sells at a premium, so operators who only need 500 watts or a lower price use the KPA500 instead.
The Elecraft KPA1500 is a 1500-watt solid-state linear amplifier with a built-in automatic antenna tuner, covering all amateur bands from 1.8 to 29.7 MHz plus the 6-meter band at 50 to 54.2 MHz. Its output stage is a pair of LDMOS transistors run from a 50-volt high-current supply, and 50 to 60 watts of drive produces the full legal-limit output. The internal tuner has two SO-239 antenna outputs with per-band and per-antenna memories, matching up to 3:1 SWR at the full 1500 watts and up to 10:1 at reduced power on the HF bands.
The amplifier comes in two cabinets: a 22-pound RF deck and a separate 17-pound switching power supply, each the same size, joined by an Anderson PowerPole high-voltage cable and a 15-pin control cable. The power supply runs only on 200-250 VAC and ships with a NEMA 6-20 plug, so a dedicated 240-volt, 20-amp circuit is required. Operation is instant-on, with RF-sensing automatic band switching that follows almost any transceiver from the keyed RF, silent PIN-diode transmit/receive switching, and a 100% ICAS duty rating that suits FT8 and other high-duty digital modes. A low-level Pure Signal sample output supports closed-loop pre-distortion to reduce intermodulation.
The rear panel carries an RCA key input, an adjustable ALC output, a 3.5 mm serial port for Elecraft and Kenwood band data, a tune jack for Icom remote tuners, and USB plus Ethernet for full remote control and firmware updates through the KPA1500 Utility. Over the KPAK3AUX cable it integrates with the K3S and sits at the top of Elecraft's line beside the K4. Operators who need only 500 watts, a single cabinet, or a lower price choose the KPA500 instead.