[Elecraft] Crystal Filter Offset in 4.81, What does it mean?

[Wayne Burdick]

Arie Kleingeld PA3A <pa3a at xs4all.nl> wrote:

> Lyle,
> 
> What are you saying here?

Arie,

The K3 has excellent opposite sideband suppression (the combined suppression of the crystal filters in the first I.F., and the DSP in the second I.F.). 

The present change (allowing you to move the crystal filter edge) came about because exactly *one* customer in England claimed to be hearing an OSB image at extremely low pitch in CW mode in the presence of "monster" signals. This was the first such comment I had heard about the K3, which isn't bad considering we've shipped some 8000 of them.

We added the new menu entry to satisfy this demanding customer because, as I told him a the time, I didn't want anyone to ever hear an OSB image, no matter how small, on the K3. He's using the 0.3-kHz setting, though I couldn't tell any difference between 0.2 (the default) and 0.3.

At one point in the K3's history, 0.1 was the setting used. Even then there were no complaints about OSB images, so if you want lower pitch, go for it.

73,
Wayne
N6KR