The KX3 transceiver is designed for HF amateur band operation. The KX3 natively supports 160m - 6m.
An optional 2m accessory can extend the band support to 2m, though the installation of that accessory is a more intensive, electronics hobbyist task.
As with all radios, do not transmit when the antenna is disconnected. Avoid touching the antenna or feed line when transmitting. Power down the radio and disconnect the feed line when making antenna adjustments.
Avoid excessive temperatures:
- When charging internal batteries, select 4 hours or less. Only charge when necessary.
- After transmitting for a few hours, cease transmission to let the radio cool off.
- Optionally, install a heat sink over the top edge of the transceiver.
Avoid excessive ALC (during excessive drive, the meter will read either 10+ bars, or no bars).
When opening the radio, be gentle. Avoid accidentally dislodging or damaging the internal wires and components, such as when replacing internal batteries or installing accessory modules.
- KX3 shield (heat sink optional)
- Elecraft USB-A to 3.5mm TRS data cable
- Elecraft PTT microphone
- CW paddles + suitable CW cable
- 3.5mm TRS audio cables
- 3.5mm TRS/TRRS headphones or earbuds (microphone optional)
- Microsoft Windows laptop
- TRRS male to TRS female microphone splitter
- portable speaker with 3.5mm TRS auxiliary audio input jack
- Hosa GMM-105 3.5mm 1-to-5 Knucklebones Signal Splitter
- HF antenna, such as an Elecraft AX1, or MFJ-1899T, or a homebrew speaker wire antenna
- Elecraft AXB1 bipod stand; or an Elecraft AXT1 camera tripod adapter with a camera tripod and 25 - 50 ft feed line with BNC connectors
- an appropriate counterpoise / grounding / radial wire
- ARRL Band Plan chart
Two grub screws unscrew a few turns, in order to release two stand legs.
The grub screw near the antenna BNC port can serve as a connection for grounding.
Power on / Power off: Press and hold Band-. Then press and hold ATU Tune. Finally, release both buttons. Recommend to habitually press the Band- button first, in order to avoid accidentally tuning, especially when antennas / feed lines are disconnected.
Main menu access: Press, hold, release DISP.
Navigation: VFO knob.
Value selection: Frequency knob.
Confirm main menu selection: Press, hold, release DISP.
Mode selection: Press and release MODE.
Antenna tuning: Press and release ATU TUNE. Optionally, tune a second time.
Assign the same frequency in A to B: Press and release A>B.
Swap frequencies A and B: Press and Release A/B.
Most buttons and knobs feature additional menus via quick press and release; as well as press, hold, and release.
Settings generally apply and persist on a per-band, per-mode basis. Explicitly power down prior to disconnecting external power sources, in order to save the current settings.
- KX3 requires 8x AA internal batteries in order to boot up, even when using an external power source.
- Prefer 8 x NiMH rechargeable AA internal batteries (nominal 1.2V).
- Set low battery threshold to 8 x 1.2V = 9.6V.
- Recommend Adafruit USB Type C 3.1 PD to 5.5mm Barrel Jack Cable - 15V 5A Output adapter for either internal battery charging, or continuous external power supply.
- Recommend FXLION Nano ONE V Mount Battery 14.8V as a more convenient power source than the internal batteries. This also keeps the internal batteries in reserve as an emergency backup.
- When using USB Type C AC wall adapters to charge internal KX3 batteries, disconnect other devices. Many wall adapters lack sufficient output power to charge the KX3 and other devices simultaneously.
- Setting BKLIGHT off minimizes power drain.
- Setting AF gain low minimizes power drain.
- Using headphones or earbuds minimizes power drain.
- Power on the KX3. (This requires a minimum level of internal battery charge remaining.)
- Open the main menu.
- Select BAT CHG.
- Select 4 hours.
- Optionally, power down. The screen will show a charge countdown timer.
- Ensure KX3 has sufficient internal battery charge (no low battery warning).
- Connect Elecraft USB-A to 3.5mm TRS data cable from a computer to the ACC1 3.5mm TRS data input jack.
- Launch the Elecraft utility application.
- Download the latest primary and DSP firmware from Elecraft.
- Extract the firmware files to a known file system path.
- Use the Elecraft utility application to import the file system path.
- Check the KX3 installed vs latest cached firmware versions.
- Optionally, backup KX3 user configuration.
- Optionally, set a new boot message like "HELLO WORLD" rather than the confusing, default CQ ATX message.
- Update firmware. This can take several minutes.
- Select an appropriate band.
- Select an appropriate frequency.
- Select an appropriate phone mode, such as AM, FM, LSB, or USB (Upper Side Band).
- Select the desired transmission power, e.g. 5W - 10W.
- Tune the antenna.
- Monitor the frequency for the noise floor. Optionally, adjust the AF/RF-SQL/MON knob to the desired speaker volume.
- Use the main menu to enable MIC BIAS.
- Use the main menu to set MIC BTN to PTT.
- Connect a PTT microphone to the MIC 3.5mm TRS audio input jack.
- Use the Keyer/Mic/Pwr knob to lower microphone gain, about 22 dB.
- Press the microphone PTT button. Repeat "Test " at a comfortable volume, while adjusting the microphone gain, until the ALC meter reads about 5 bars.
- Call CQ, join nets, respond to CQ, etc.
- Select an appropriate band.
- Select an appropriate frequency.
- Select CW mode.
- Select the desired transmission power, e.g. 5W - 10W.
- Tune the antenna.
- Monitor the frequency for the noise floor. Optionally, adjust the AF/RF-SQL/MON knob to the desired speaker volume.
- Use the main menu to disable MIC BTN.
- Connect a CW paddle or straight keyer to the key 3.5mm TRS audio input jack.
- Use the Keyer/Mic/Pwr knob to lower microphone gain, about 22 dB.
- Select VOX.
- Select the desired WPM.
- Key "Test ", while adjusting the microphone gain, until the ALC meter reads about 5 bars.
- Optionally, enable TEXT decoding.
- Call CQ, join nets, respond to CQ, etc.
- Select an appropriate band.
- Select an appropriate frequency.
- Select data mode.
- Select the desired transmission power, e.g. 5W - 10W. For WSPR, recommend 5W in order to stabilize ALC.
- Tune the antenna.
- Use the main menu to disable MIC BIAS.
- Use the main menu to disable MIC BTN.
- Connect Elecraft USB-A to 3.5mm TRS data cable from a computer to the ACC1 3.5mm TRS data input jack.
- Many digital radio modes require sub-second clock accuracy in order to function. Ensure the computer is synchronized within one second to the correct civilian time, such as reported by NIST NTP servers. Regularly re-sync the time as necessary. The time.is service can identify the current accuracy of your computer's clock.
- Launch WSJTX or similar amateur radio data application.
- Set the computer's CAT to COM3.
- Apply the desired digital mode, e.g. WSPR, FT4, FT8, etc.
- Using either the KX3 controls and/or the amateur radio data application controls, adjust the frequency for the application.
- Connect the KX3 phone female 3.5mm TRS audio output jack to the microphone splitter's female microphone jack.
- Connect the KX3 microphone female 3.5mm TRS audio input jack to the microphone splitter's female headphone jack.
- Connect microphone splitter's 3.5mm TRRS male jack to the computer's 3.5mm TRRS headset female jack.
- Optionally, insert a portable speaker, two 3.5mm TRS audio cables, and a knucklebones splitter between the KX3 microphone or phone jack and the microphone splitter, in order to monitor transmission or reception in analog during digital operation, for troubleshooting purposes.
- Configure the amateur radio data application to target the microphone splitter for input and output audio devices (often registered as a "headset").
- For FT-based modes, set the application's output Pwr to match the KX3 transmission power.
- Set the data application's signal Pwr low.
- Use the Keyer/Mic/Pwr knob to lower microphone gain, about 22 dB.
- Set the computer's audio output volume to 50%. Some data applications will relect this same volume in the transmission signal, while others may not. But it's a good habit to develop, in order to establish good ALC.
- Activate the data application's tuning feature. While the data tuning signal is running, adjust the microphone gain, until the ALC meter reads about 5 bars.
- Conduct data activities, call CQ, respond to CQ, etc.
Note that self spotting reports may succeed more often with FT8 than WSPR, due to the limited number of WSPR monitoring stations.