[Elecraft] KX1: Can I Improve Opposite Sideband Rejection?

[Mike Morrow]

> Can the opposite sideband rejection of the KX1 be improved? The
> receiver is sensitive enough, but, when I have a strong signal,
> as I tune by it, I can hear the signal on both sides of the BFO.

That's characteristic of the KX1, which uses a 3-pole crystal filter
network in its IF.

The K1 has much better opposite sideband rejection because it has a
four-pole crystal filter network.

I supposed one could re-design the KX1 to add an extra IF crystal.
I wish that had been part of the original design.  I think it's
an important performance attribute, even on small QRP rigs.  It costs
so very little in terms of space, PCB real estate, and cost of parts.
It does make a noticeable difference.

Mike / KK5F