The Elecraft K4 is a direct-sampling SDR 160 to 6 meters all mode transceiver. It features a large 7″ full-color touch display, and has an HDMI jack for an external display. There is a rich and intuitive set of controls, and a nice DVR.
The easily adjustable DSP features are standard, there are receive, transmit, and equalizer settings for each mode. The direct sampling technology produces an extremely flat passband response resulting in cleaner transmit and receive audio. The DSP can be upgraded in the field to add new algorithms and modes.
The Elecraft K4 has dual receivers that cover from 100 kHz to 54 MHz, and full DVR capabilities plus several built-in data encode/decode modes. A high resolution mini-pan for each receiver cover 1kHz in CW, and 5 kHz in SSB, which allows fine tuning at contest speeds.
The K4 is designed to be 100% remote controlled by computer, another K4, or ethernet. The remote displays include panadapters. There are three USB A ports, one in the front and two in the rear. You will 1 to 4 so239 antenna ports depending on the hardware you choose. There is four BNC connector for transverters, or beverage antennas plus all the standard connection that high end radios include.
Three Models of Elecraft K4
- Basic K4 with dual receive
- K4D with diversity receive
- K4HD with a dual superhet module
The software is updatable via the internet. Hardware can be updates as it becomes available by you, or by sending it in to the factory. The new K4’s CPU provides unlimited room for expansion.
The optional KAT4 antenna tuner can tune a whopping 10:1 matching range can be added during the original purchase or at a later date. It includes 3 antenna jacks, any one of which can be selected as an input for one or both receivers.
- 100 kHz – 54 MHz RX frequency
- VHF/UHF range to be determined
- +/- 0.1 ppm typ.
- CW, SSB, AM, FM, and Data modes
- 7” LCD color touch & mouse control
- CW, PSK31/63, RTTY Text modes
- ATU: 10:1+ range; 3 ant. jacks (Optional)
- Up to 5 Antennas
- 16 bit A to Converter/s
- 11-15 VDC
- 2-3 A RX current drain
- 4-23 A TX current drain
- 3 USB-A
- 1 USB-B with two VCP’s plus audio
- 1 DE9
- 1 Ethernet
- 1 video output
- 1 Rear mic
- 1 Rear phones
- 1 TX sample in
- 1 REF in
- 1 LINE in/out
- 1 RX in/out
- 1 Ant in/out
- 1 Txvr in/out 2nd RX ant
- 1 speakers
- 1 PTT in
- 1 KEY out
- 1 Paddle
- 1 CW key
- 1 15 ACC
- 1 12 V out
- 1 Ground screw ,wingnut
- 4.5”H x. 13.5”W, 10” D
- Approx. 10 lbs.
Elecraft K4 Review
The 7″ color display is amazing, and the touch sensitivity is just right. The controls are thoughtfully laid out leaving room for expansion. Having independent controls for the A and B bands is nice, I use the K-POD for controlling the B band during split operation.
The flip down stand on the bottom is the highest one I have seen on a radio, and I like it. I usually have a short piece of 1×3 under it with other radios. The internal fan has 4 speed levels that I can set, but it is not on a thermostat. The menu is one of the best I have used, My radio arrived slightly off frequency, And I was able to adjust it using the WWV and reference frequency in about 5 minutes. Other radios would have been on the way beck to the factory.
The update process is painless.t is finished in a few button pushed using the internet connected to the radio. Having three USB ports is very handy, I have a mouse in one of the rear ones leaving the one in the front open for thumb drives. There is a microphone input and key jack, both in 3.5mm, for a headset in the rear which is nice. I would like to see the 8 pin foster jack in the rear to keep the front of the clean, but none of the manufactures do this.
Elecraft K4 and Amplifier
I paired this up with the Palstar LA1K and AT2K using my Skyloop antenna that I already owned. They do not communicate with the radio like a KPA500/1500 does, but works very well like it is. I did have to make my own interface cable, because I could not find one for this set up.
The receiver is the best I have heard to date, clear and punchy signals. Rob Sherwood has done some great testing on the K4, and shown the receiver is in the top 5 of all. Add in all the other features, and this is a next generation radio.
The internal keyer works very well, but the weight settings were different from my Yaesu. The optional tuner when working at low power is great, it is a beast and sounds like a machine gun a little. The start-up process scares me sometimes, the pop sound is amplified because of my amplified Bose speakers. But this is normal for the K4.
The computer connection was one of the easiest I have dealt with, the two ports showed up and work perfectly. I plugged a 22″ monitor into the display port, and it looks fantastic. The choice to get the K-pod was an easy one, and it speeds frequency changes during a contest.
The extra 16 macro buttons can be set for most radio features, including the memory channels. I kike to use the K-pod on VFO B when working split, because I can turn both frequencies. The third position on the rocker switch controls the RIT/XIT knob where I have the pan span set for quick span changes.
I have also used an HDMI capture card to put the display image on my computer. The mini pan is absolutely a fantastic feature, it makes tuning CW and SSB much quicker. This is a nice radio, and I can not wait to see what the future software may bring us.