KX2 Firmware Information

KX2 MCU 3.02 / DSP 1.52, 18 MAR. 2022

* MORE OPERATIMG TIME AT 10 W IN CW MODE:  In CW mode, we now allow up to 10 W output as long as the supply is above 9 V (key-down). In other modes the criteria for 10 W output is still 10 V. This is required to preserve low transmit IMD.

KX2 MCU 3.01 / DSP 1.52, 20 NOV. 2021

* KXIBC2 INTERNAL BATTERY CHARGER SUPPORT:  If a KXIBC2 is installed, set MENU: KXIBC2 to NOR. This will allow the operator to optional monitor battery voltage by tapping DISP and selecting the “BT XX.X” display (by rotating the VFO B/OFS knob). Internal battery charging is automated and can be done with or without the radio turned on. When charging is in progress, the KXIBC2’s yellow LED is illuminated. For further details, refer to the KXIBC2 manual.

KX2 MCU 3.00 / DSP 1.52, 6-8-2020

* LPF RELAY CONTROL IMPROVED:  Longer on/off pulses are now sent to the latching relays on the RF board to ensure reliability at temperature extremes. If problems persist with the 40/60 meter LPF relay, add a jumper from the “SPARE A” pad (U1 pin 26) to U1 pin 2. This revision of firmware uses the SPARE A I/O expander output (GPA5) as a supplemental to the original 40/60 meter relay drive line.

KX2 MCU 2.97 / DSP 1.52, 4-27-2019

* ATU TUNING IMPROVED WITH LOW SUPPLY/BATTERY VOLTAGE:  ATU tuning should now be reliable down to as low as 8.5 V. Results may vary somewhat due to component tolerances, but all radios should show improvement.

KX2 MCU 2.94 / DSP 1.52, 12-3-2018

* AM MODE TX POWER CONTROL IMPROVED:  AM mode power output level is now maintained closer to the target.

* ADDED SWR READ COMMAND:  "SW;" returns the most recent SWR reading in transmit or TUNE mode, e.g. "SW023;" for an SWR of 2.3:1. The value is not automatically updated on band change; update always occurs on any transmit. Max value returned is "SW99;" (SWR = 99.9:1).

KX2 MCU 2.89 / DSP 1.52, 12-10-2017

* ADDED FM MODE:  FM mode can be used on any band, but it is intended for use with 10-meter repeaters (or 10 meter FM simplex DXing) as well as with external transverters. (For transverter band display setup instructions, see owner’s manual.)  FM is considered experimental on the KX2 pending field test results.

FM Instructions: 
   - FM mode can be enabled or disabled using MENU:FM MODE
   - To adjust squelch, tap FIL, then rotate the AF GAIN knob
   - To select +/-/SIMPLEX repeater offset, hold SPLIT 
   - Set up repeater splits per-band/per-memory using MENU:RPT OFS
   - Adjust FM deviation using MENU:FM DEV
   - To adjust PL tone deviation, locate MENU:FM DEV, then tap ‘1’ (PRE) 
   - To select PL tone, use MENU:FM TONE. Tap ‘1’ to turn tone on/off. 
Note: 1750 Hz tone not usable at this time.

* MIC REMOTE FUNCTIONS: These functions are being redesigned and have been temporarily disabled.

KX2 MCU 2.86 / DSP 1.52, 11-30-2017

* MAX POWER OUTPUT NOW 12 W ON 80-20 METERS. This power level is intended for light-duty cycle operation, e.g. hunt and pounce. (Note: When using 12 W, recommended supply voltage is 13.5-14 V; minimum 12.8 V. 12 W output is not guaranteed. If current drain is excessive, reduce power.)

KX2 MCU 2.84 / DSP 1.52, 11-21-2017

* SW TONE SETTING BUG FIX:  Corrected a problem that prevented Morse audio tones from being turned off once turned on using the SW TONE menu entry.

KX2 MCU 2.81 / DSP 1.52, 10-5-2017

* MH3 MIC EXTENDED RADIO CONTROLS:  See separate document, “KX2 Remote Control Using the MH3 Mic.”

* MH3 PTT DOUBLE-TAP FREQUENCY REPORT:  Tapping PTT twice quickly reports the current operating frequency as 3 digits in Morse code audio. For example, if you’re on 14.285 MHz USB, the report will be “U 285”. This is useful in conjunction with MH3 extended radio controls (see above), as well as during mobile operation.

KX2 MCU 2.80 / DSP 1.52, 10-2-2017

* TXCRNUL MENU PARAMETER FIX:  This parameter now has a range of -9999 to +9999.

KX2 MCU 2.79 / DSP 1.52, 9-10-2017

* SIDETONE VOLUME CAN BE SET LOWER:  MON=1 is now about 12 dB lower in volume than it was originally. MON=50 is about the same as the original maximum.

* AUTO-OFF TIMER RANGE IS 5 TO 100 MINUTES:  Auto-power-off (MENU: AUTO OFF) allows the radio to turn itself off if no controls are touched for the specified length of time. (The original range was 3 to 20 minutes.) If auto power-off is not desired, set the menu parameter to INFINITE (default). 

* VFO A LOCK DISABLES COARSE VFO A TUNING WITH OFS/B CONTROL: This is intended to prevent accidental frequency changes due to touching the OFS/B control. As long as VFO A is locked, the offset-tuning feature will also be locked. (RIT, if used, is still *not* locked. RIT may be needed to fine-tune received signals even if the VFO itself is locked on a given transmit frequency.)  Note: Coarse tuning steps for VFO A are set up per-mode using MENU:VFO CRS. The OFS/B control can be used to coarse-tune VFO A if RIT and XIT are both turned off and the control is not assigned to VFO B (“B” LED).

* FILTER BANDWIDTH & ULTIMATE ATTENUATION FIX:  Filter bandwidth settings ending in x00 Hz are now increased internally to x50 Hz to ensure excellent ultimate attenuation (stop band). For example, a setting of 400 Hz becomes 450 Hz. This is a temporary workaround for a DSP algorithmic issue with the x00 settings that will be corrected in a future release. Available bandwidth settings are now 50 Hz, 150 Hz, 250 Hz, 350 Hz, etc. These are entirely adequate for virtually all operating purposes. 

KX2 MCU 2.77 / DSP 1.50, 5-26-2017

* BUILT-IN LOGGING (CW and DATA MODES):  When using the KX2 hand-held, logging may be difficult. The KX2 can now capture up to 2048 transmitted characters, along with time, band, and mode, so you can update a paper or electronic log later on.
     To enable logging, set MENU:LOGGING to ON. Logging applies to CW (C), PSK-D (P) and FSK-D (F) modes, and only when using the internal keyer. To take advantage of time stamping, either set the time (MENU:TIME) on every power-up of the KX2, or install a KXIO2, which includes a real-time clock powered by the internal battery.
     When logging is enabled, the DVR icon (above the S-meter) flashes slowly. Outgoing text decode is turned on, allowing you to make sure you’ve sent call signs accurately. If you fill the log, LOG FULL will be shown briefly, and the DVR icon will stop flashing. 
     To review logged text, tap DISP and rotate VFO B to find the LOG display. The VFO A knob can then be used to scroll through text. Time/mode/band are shown on VFO A (e.g., “0023 C14”); text is shown on VFO B. Holding CLR erases the entire log.
     To “dump” the log, send “LG;” to the KX2 via KX2 Utility’s Command Tester screen.
     Tips: To conserve space, use message buffers (MSG) to send CQs, name/QTH, etc. Messages are not recorded in the log. To start/stop logging quickly, assign the LOGGING menu entry to a programmable function switch (PF1-PF4).
  
KX2 MCU 2.75 / DSP 1.49, 4-3-2017

* FOUR PROGRAMMABLE FUNCTIONS:  The KX2 now has four programmable functions, PF1-PF4, rather than one. These can be used to quickly access often-used menu entries. To set up a programmable function, locate the desired menu entry, hold PFn, then tap any of ‘1’ through ‘4’. Exit the menu. From then on, the menu function can be accessed using the associated PFn switch. If a menu entry has only two values (such as ON/OFF), accessing it via a programmable function will select the alternate value, then exit the menu immediately. This is especially useful with menu entries such as DUAL RX, VOX MD, ALT MD, and ATU DATA (see rev. 2.73, below).

KX2 MCU 2.73 / DSP 1.49, 3-30-2017

* TWO ATU DATA SETS:  The KX2 will now store two full sets of per-band data for the internal ATU (KXAT2). Use the ATU DATA menu entry to select which set to use. Typically SET 1 is used at a home location, and SET 2 for field operation. They can also be used in cases where more than one antenna is available for a given band. (Note: The ATU DATA menu entry has no effect on KXAT100 ATU data, which is already stored separately for each of the KXPA100 amplifier’s antenna jacks. The KX2 can remotely switch KXPA100 antennas using the ANT.X SW menu entry.)

* ATU LC NETWORK VALUE DISPLAY:  In either the ATU.DATA or ATU MD menu entry, tapping the "ATU" switch shows the present values of L (inductance), C (capacitance) and N (L-network configuration). This applies only to the internal ATU (KXAT2). The displayed data format is LxxCxxNy. <xx> is a 2-digit hexadecimal value that, when converted to binary, shows which ATU L or C relays are engaged. <y> shows which side of the L-network the capacitance is on: Nt = TX side, and NA = antenna side.

* ATU CLEAR AFFECTS ONLY CURRENT DATA SET: Within the ATU DATA or ATU MD menu entries, CLR (hold of the OFS/B knob) now clears KXAT2 ATU data only for the presently selected data set (SET 1 or SET 2) on the present band. As before, CLR is recommended when using the internal ATU with a new antenna. Once the data is cleared, very few ATU tune operations will usually be needed to cover an entire band. Note: If a KXPA100 amplifier is connected, the CLR operation applies to the KXAT100 ATU’s per-band/per-antenna data, not to the data for the internal KXAT2 ATU.

KX2 MCU 2.71 / DSP 1.49, 1-30-2017

* PSK-D/FSK-D SIDETONE HANG FIXED:  Corrected a problem where sending characters at very slow speeds or with paddles continuously pressed could cause a transmit timeout, leaving the sidetone on.

KX2 MCU 2.69 / DSP 1.49, 9-6-2016

* PSK63 FIX:  DSP revision 1.49 corrects a problem with PSK63 mode. 

* ALT MD MENU ENTRY IMPROVEMENT:  Some users found that the ALT MD menu entry didn’t switch modes consistently or cleanly. This is a long operation internally to the firmware, so the VFO A knob rate was slowed down (parameter adjust).

KX2 MCU 2.68 / DSP 1.48, 8-23-2016

* AM MODE ADDED:  AM mode is now available on the KX2. (AM mode can be removed from the MODE switch rotation by setting MENU:AM MODE to OFF.) AM Receive: AM mode can provide a “warmer” sound when used to copy shortwave broadcast stations, and VFO tuning is less critical than when using SSB modes to copy AM. MENU:VFO CRS provides coarse-tuning selections of 1, 5, 9 and 10 kHz for AM mode. AM Transmit:  AM is far less power-efficient than SSB, so SSB is preferred for most communication purposes. However, AM is in use on the ham bands. A good place to look for AM signals is around 3.870 MHz at night. Note: Speech compression should in general be turned off when transmitting in AM mode (set MENU:TX CMP to 0). 

KX2 MCU 2.67 / DSP 1.48, 7-16-2016

* ALT MD (Alternate Mode) MENU ENTRY IMPROVED:  When ALT MD is assigned to the programmable function switch (PFn), holding the switch selects NOR or ALT on successive presses without remaining in  the menu. (ALT MD is used to select between LSB/USB, CW-norm/CW-reverse, or DATA-norm/DATA-reverse on a per-band basis.)

KX2 MCU 2.66 / DSP 1.48, 6-24-2016

* DSP BUG FIXES: Eliminates the “ERR DSP” and “ERR DSE” error conditions that appeared on a small number of KX2s, typically at power-up.

KX2 MCU 2.62 / DSP 1.46, 6-15-2016

* MIC BTN, MIC BIAS, and all VOX MENU SETTINGS ADJUSTABLE IN ALL MODES: Locking these out was causing problems in some cases. None of these settings apply to the internal mic, but you can now adjust them with or without an external mic plugged in.

KX2 MCU 2.61 / DSP 1.46, 5-31-2016

* AUDIO-CW USER INTERFACE IMPROVEMENTS:  The KX2 can emit CW characters when switches are pressed and knobs are turned, etc. For details, see the document, “Elecraft KX2 Physical Description and Audio-CW User Interface.” Audio-CW tones can be enabled in the menu (see MENU:SW TONE), or on power-up, by holding APF along with RATE and A/B. Release RATE and A/B first, then release APF. This sets the speed to 20 WPM. The menu entry provides more speed selections. 

KX2 MCU 2.60 / DSP 1.46, 5-11-2016

* MONITOR LEVEL CONTROL GRANULARITY IMPROVED.

* AF GAIN CONTROL GRANULARITY IMPROVED.