Elecraft K3S
firmware v1.66
Elecraft · Released Jan 29, 2008 · First seen Sep 14, 2026
Source:
elecraft.com
v1.66 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
Fixed ATU TUNE to automatically use 5W/10W power instead of TUN PWR menu value
- ATU TUNE power corrected to automatic 5W/10W operation
- No longer affected by TUN PWR menu or power knob
Written from Elecraft's release notes, which are printed in full below.
Was this useful? Thanks.
What's in this update
- CORRECTED ATU TUNE PROBLEM: In version 1.65, tapping ATU TUN would use the value set in the new TUN PWR menu entry, and afterward set the power knob to the TUN PWR value.
The ATU TUNE power level is supposed to be fixed (5W and 10W, automatically controlled). It should not be affected by either the TUN PWR menu entry or the power knob.
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