[Elecraft] KX3 Sherwood RX Test Numbers Posted

[Matt Maguire]

Jim,

This is my understanding of note "v":

The KX3 is a direct conversion architecture, and relies of the I & Q signals to cancel out opposite sideband. For this cancellation to work, the balance of amplitude and phase needs to be very precise, and it looks like Elecraft have managed to get the image to be 65dB down, which is very good.

Based on the note "v" comment, it seems for the case of CW, this image will normally occur 1kHz away from the desired signal. If you have a close-in signal 1kHz away, then what you can do is enable 8kHz shift, which means the image is now 16 kHz away. Now the close-in dynamic range is 96dB, since the roofing filter can't be used with the 8kHz IF. Of course, if you are unlucky enough to have a strong signal 16kHz away (on the other side of your LO), then this signal will be down 65dB.

73, Matt VK2ACL

On 11/08/2012, at 5:39 AM, Jim Brown <jim at audiosystemsgroup.com> wrote:

> Great numbers!  Wayne has outdone himself again.
> 
> Can you explain note "v?"
> 
> 73, Jim K9YC
> 
> 
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