[Elecraft] DDS-VFO Maybe off Topic

[John, KI6WX]

Lee;
A DDS VFO does have some issues when used to directly drive a transmitter. 
The biggest one is spurious outputs.  These may be only 70 dB down from the 
carrier and a few kHz to 100's of kHz away.  Now when you are running low 
power, such as the KX1, this doesn't matter too much.  But if you directly 
run a kW from a DDS VFO, you may make some other folks not too happy with 
your spurious outputs.

-John
 KI6WX


>
>  I've been researching the DDS VFO topic on the Internet and found that 
> somethings have been done in this area in the USA, but most of the sites 
> are found in Japan or Europe.  Why has the DDS-VFO type of circuit caught 
> on here?  I am looking for a kit or a project I could build for some Xtal 
> control rigs I have rather than buy Xtals.  Seems to me that would a nice 
> way to go.  I know that Flex Radio has done quite a bit of work with DDS 
> and so has Elecraft.  I wonder if there is a market out there for DDS VFO 
> technology and a crystal replacement....
>
>  Lee - K0WA