Elecraft K3S vs Elecraft K4
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Elecraft K3S or Elecraft K4? I’ve put both radios side by side: data from the manufacturers’ spec sheets and photos at the same scale. The Elecraft K3S wins on transmit current draw and weight; the Elecraft K4 wins on the second receiver, spectrum and waterfall, LAN / remote operation and memory channels.
ElecraftK3S
HF · 6 m100 Wtuner3.8 kgdiscontinued
ElecraftK4
HF · 6 m100 Wtuner4.5 kg
Specs side by side
| ElecraftK3S▲ 2 | ElecraftK4▲ 4 | |
|---|---|---|
| Bands and modes | ||
| Transmit bands | HF 1.8–29.7 MHz50–52 MHz | HF 1.8–29.7 MHz50–52 MHz |
| Receive range | 0.1–30 · 44–54 MHz | 0.1–54 MHz |
| Modes | SSBCWAMFMRTTYPSK | SSBCWAMFMRTTYPSK |
| Transmit power | ||
| HF | 100 W | 100 W |
| 50 MHz (6 m) | 100 W | 100 W |
| Receiver | ||
| Construction | down-conversion superhet (1st IF 8.215 MHz), up to 5 crystal roofing filters (from 200 Hz), DSP at the 2nd IF (15 kHz) | SDR, direct RF sampling; modular (upgradeable to K4D / K4HD) |
| Second receiver | — | dual receive on any bands (shared A/D converter; K4D: separate KRX4 receiver) |
| Spectrum and waterfall | — | dual spectrum + waterfall, mini-pan |
| Features | ||
| Antenna tuner | internal KAT3A option, up to 10:1 SWR | internal KAT4 option, up to SWR 10:1 (160 and 6 m: 5:1) |
| Display | segmented LCD, backlit | 7″ colour touchscreen; HDMI output |
| LAN / remote operation | — | built-in LAN, remote operation without a PC (K4 ↔ K4, K4/0) |
| USB | USB-B: CAT + audio; RS-232 (RJ-45) | USB-B: CAT + audio, 3× USB-A (1 on the front) |
| SD card | — | — |
| Antenna connectors | 1× SO-239 (2× with KAT3A) + RX ANT, XVTR (BNC) | 1× SO-239 (3× with KAT4) + RX ANT, XVTR (BNC) |
| Power and case | ||
| Power | 13.8 V DC, external power supply | 13.8 V DC, external power supply |
| Transmit current draw | 22 A ▲ | 25 A |
| Dimensions | 272 × 102 × 254 mmwidth × height × depth | 343 × 114 × 280 mmw × h × d |
| Weight | 3.8 kg ▲ | 4.5 kg |
| Other | ||
| Memory channels | 100 | 200 ▲ |
| Release | 2015discontinued | 2020 |
Data: manufacturers’ spec sheets and manuals · as of 31.10.2026
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