Elecraft K3S firmware v5.67

MCU 5.67 / DSP 2.88 / FPF 1.26

• 6 M GAIN REDUCTION (FOR USE WITH KPA3A): In some cases the KPA3A may have more gain than necessary on 6 meters. As a precaution, all radios using a KPA3A (instead of the older KPA3) should be configured to insert some attenuation. See instructions below. No hardware modifications are required.

INSTRUCTIONS: [Do this only on a K3S, or a K3 that has a KPA3A installed.]

1. Sel​ect the 6 meter band.
2. Connect a dummy load rated at 50 W (or higher) to the transceiver.
3. Set the PWR control to 50 watts.
4. Place the ATU in bypass mode.
5. Locate the CONFIG: TUN PWR menu entry. Set the value to NOR using VFO A.
6. Locate the CONFIG: TXGN HP menu entry.
7. Tap the '8' switch (NR) once to add "ATN6" to the parameter display on VFO A.

(Tapping it a second time would return to the original non-attenuated setting.)

8. Exit the menu.
9. Hold TUNE to do automatic power calibration on 6 meters at the 50 W level. After a few seconds, tap XMIT to terminate the TUNE ope​ration.

NOTE: If you have difficulty reaching full power on 6 meters after making this change, it could be because your PA module is actually a KPA3, not a KPA3A.

In this case, re-do the above procedure, changing the TXGN HP menu setting back to the original (i.e., without "ATN6" showing). (Max. power output at 50 MHz is specified at 100 W +/- 1 dB, typical. 1 dB below 100 W is approx. 90 W.

See Specifications for max output at 51 MHz and higher.)

• T/R TIMING IMPROVED. Adds more margin during KPA3A TX sequencing.