Elecraft K4 firmware
Elecraft · K4 · K4 · HF transceiver
Latest firmware for the Elecraft K4 is vR38 (June 17, 2026).
Specifications
K4 specifications
- Type
- Amateur HF/VHF(UHF) transceiver
- Frequency range
- TX: 10-160 m + WARC and 60 m / 6 m / RX: 0.1-54 MHz / 2 m and 70 cm option still in planning?
- Modes
- AM / FM / SSB / CW / Data
Show the full specification Hide the full specification
General
- Mode
- AM / FM / SSB / CW / Data
- Type
- Amateur HF/VHF(UHF) transceiver
- Weight
- 4.54 Kg (10 lb)
- Power supply
- 11-15 VDC (Anderson PowerPoles)
- Tuning steps
- 1 / 10 Hz
- Other features
- Modular hybrid design for easy upgrade and expansion. DSP. 7" color touch display. HDMI video output. Ethernet jack. Remote control. Single or dual panadapter. USB-jacks. RS-232C. Transverter I/O. Iambic keyer. Twin RX. CW, PSK31/63 and RTTY encode/decode. Real-time clock. RX and TX equalizer. Built-in help system. Linux-based computing module.
- Frequency range
- TX: 10-160 m + WARC and 60 m / 6 m RX: 0.1-54 MHz 2 m and 70 cm option still in planning?
- Dimensions (W*H*D)
- 343*114*254 mm (13.5*4.5*10")
- Frequency stability
- ±0.3 ppm (No temperature reference)
- Repeater shift / offset
- ±? KHz
- Channels / memory management
- 999 regular?? 4 quick memory
- Antenna impedance / connector
- 50 ohm / SO-239 (Plus three SO-239 with optional KAT4)
- Current drain / power consumption
- RX: Less than 3 A TX: Max 25 A
Miscellaneous
- Manufactured
- USA, 2019-202x
Receiver Section
- Sensitivity
- SSB/CW (MDS) 0.1-23 MHz, Preamp OFf/1/2: -118/-128/-135 dBm 23-54 MHz, Preamp OFf/1/2/3: -118/-128/-135/-141 dBm
- Receiver system
- Direct-sampling SDR
- AF output power / speaker
- 2.5 W at 1% distortion / 4 ohm
Transmitter Section
- RF output power
- HF6 m2 m*70 cm* AM:0.1-100 W0.1-100 W (85 W)0.1-15 W0.1-15 W FM:0.1-100 W0.1-100 W (85 W)0.1-15 W0.1-15 W SSB (PEP):0.1-100 W0.1-100 W (85 W)0.1-15 W0.1-15 W CW:0.1-100 W0.1-100 W (85 W)0.1-15 W0.1-15 W * With optional VHF/UHF band module (Planned)
- Spurious emissions
- HF: Better than -50 dB 6 m: Better than -60 dB
- Microphone input level
- ? mV
- Max FM deviation (Factory set)
- FM: ±5 KHz NFM: ±2.5 KHz
- Microphone impedance / connector
- ? ohm / 8-pin (Metal locking ring connector)
Changelog
K4 firmware changelog
-
vR38first tracked Production release of beta version with known FSK RTTY limitation
Firmware history
All versions below were published by Elecraft on elecraft.com. Third-party and modified firmware is never listed.
-
Production release of beta version with known FSK RTTY limitation — summary by updatemystuff.com
Source:
elecraft.comRelease notes & downloadShow release notes Hide release notes
June 17, 2026
This release is functionally identical to R38.BETA4, which has been tested and promoted to production status. See below for details.
FSK RTTY BUG NOTE: At present, FSK RTTY transmissions from a K4/0 (or from a K4 used as a client) will not work unless TEXT DECODE is enabled. This will be addressed in a future release. (When operating a K4 standalone, FSK RTTY transmit will work with or without text decode enabled.)
Watch the K4 for updates
Get an email the moment Elecraft publishes new firmware. Just your email — no account or password needed.
