[Elecraft] Where's the KX1 feedback?

[Sverre Holm]

> The KX1 does USB and LSB by using high-side or low-side 
> injection from the DDS.  For 15m operation, it would need to 
> output at ~16 MHz and ~26 MHz. 

A DDS-based CW transmitter does not need a transmit mixer, and from the
schematics, the KX1 is no exception. For 20 meters operation, the DDS
generates 14 MHz directly, and for 15 m, it would need to generate 21
MHz directly.

My AT Sprint generates 14 MHz from a 40 MHz clock, so with the 50 MHz
clock in the KX1 and scaling, that translates to about 17-18 MHz (17m).
Another issue is transmit filtering and if the present filter is good
enough for 17 m, or if there is room for more filters. It sounds
unlikely from the reports of tight space in the KX1, but I have no
experience with the KX1 myself.


Sverre
LA3ZA