[Elecraft] Confusion on Roofing Filters

[Wayne Burdick]

Mike, w0ih wrote:

> I'm a bit confused on the specifications of the roofing filters on  
> the KX3.
> Will there be a roofing filter that is standard...?

The KX3's direct-conversion/quadrature (I/Q) receiver works with or  
without roofing filters. You could certainly start with the basic unit  
and add the roofing filter module later, if necessary, for your  
operating conditions.

In fact, the KX3 is the only transceiver of this type that we know of  
that even offers a balanced roofing filter in the receive I/Q path.  
It's been a challenge, but we the results will be worth it. Adding  
this module makes the KX3's receiver perform more like a superhet,  
with better blocking and IMD dynamic range. But it will retaining the  
advantages of I/Q demodulation, including very flat passband response,  
fewer mixing spurs, no-tune RF filtering, and the ability to use SDR  
(software-defined-radio) applications.

We'll clarify all this when we update the KX3 brochure.

73,
Wayne