Elecraft K3S
firmware v4.73
Elecraft · Released Nov 11, 2013 · First seen Sep 14, 2026
Source:
elecraft.com
v4.73 is not the latest firmware for the Elecraft K3S: the current version is v5.67 (January 22, 2019). Go to v5.67
In short — summary by updatemystuff.com
RIT can now be toggled during transmission, crystal filter offset adjustable in CW.
- RIT toggles during transmission via switch and remote command
- Crystal filter lower edge adjustable in CW to 0.1, 0.2, or 0.3 kHz
- A>B switch sends VFO update in AI2 mode for computer control
Written from Elecraft's release notes, which are printed in full below.
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What's in this update
MCU 4.73 / DSP 2.82
- RIT CAN NOW BE TURNED ON/OFF DURING TX: This applies to both the RIT switch and the "RT" remote-control command. Note: If RIT is turned on or off during transmission of a CW character, the length of one code element may be affected. This will be corrected in a future release.
- CRYSTAL FILTER OFFSET ADJUSTABLE IN CW MODE: You can now set the crystal filter lower edge in CW mode to 0.1, 0.2, or 0.3 kHz above zero beat. The default is 0.2 kHz. The 0.1-kHz selection provides enhanced bass response, but may allow you to hear a low-pitched opposite-sideband signal when tuned near very strong signals. The 0.3-kHz selection may be preferred by some operators in extremely strong-signal environments. To change the setting: Select CW mode, then go into MENU: RX EQ and tap '0' (CWT) to choose the desired XFIL LO value.
- A>B SWITCH TAP SENDS VFO UPDATE IN "AI2" MODE: This is useful for those writing computer-control applications.
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