Elecraft K3S
firmware v4.77
Elecraft · Released Dec 30, 2013 · First seen Sep 14, 2026
Source:
elecraft.com
v4.77 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
RS232 data handling fixed during band changes.
- RS232 data no longer locked during band changes
Written from Elecraft's release notes, which are printed in full below.
Was this useful? Thanks.
What's in this update
MCU 4.77 / DSP 2.82
- NO LOSS OF RS232 DATA DURING BAND CHANGES: On any band change, the K3 sends band data to possibly-connected XV-series transverters and the KRC2. This takes 15 milliseconds, during which RS232 data (from PC applications) was locked out. RS232 data is now properly handled during this time, which could eliminate some K3-to-PC communications issues on band change.
updatemystuff.com never hosts firmware files — always download from the official source.
Get it from ElecraftWatch the K3S for updates
Create a free account and get an email the moment Elecraft publishes new firmware.
Create account & watch