[Elecraft] K3 - FT8 - low power issues when TX audio below 900hz

[LA8AW]

Hi,

On all HF bands I have very low power output when I TX with a audio
frequency below  900hz. Between 900 - 2300hz all is normal.  On 50Mhz,
power the output start dropping when I come below 500Hz. (FL1 2.7 selected
on all bands)

Using Microham MicroKeyer II; Audio switching is set to Digital settings,
using line in (rear). Tested with 2 different MicroKeyer II same result.

FT8 is soundcard configured Input: Line (microham CODEC), Output: Headset
Earphone (microHAM CODEC).

This was causing problems for me when I tried to work stations running DX
Mode (KH1).

K3 with the "new" synth card, all mods done.
Filters installed: 2.7, 1.8, 1.0, 0.4, 0.25
DATA enabled for all filters

Any hints on where to look next?


73 de LA8AW - Odd-Egil