[Elecraft] ADT-200A Fully DSP transceiver

[Paul Christensen]

Eric Swartz:

> At 50W it will not have enough drive to drive most legacy tube based
> amps to full power, especially the widely used 3-500z based legacy amps
> from Heath and Ameritron.

Very true.  But I suspect few owners of the ADT-200A would even consider 
using it with such an amplifier.

What the ADT-200A does presently offer -- that nobody else does at the 
moment, is utilize an advanced PA pre-distortion technique (apply opposite 
non-linearity) to significantly drive down transmitted RF non-linearities 
(typically -50 dBc 3rd-order).

Moreover, the transceiver, right out of the box, allows the user to sample 
the output of an amplifier (I plan on using an SPE 1K-FA) and feed the RF 
sample back into the transceiver's monitor point such that the 
pre-distortion algorithm drives down IMD of the total transmitted output. 
For amateur radio, that's an extremely novel and powerful feature derived 
from Mil and commercial applications.  In effect, the ADT-200A takes a 
solid-state amplifier that would otherwise offer only mediocre SSB IMD 
performance and turn it into one with stellar performance -- without ever 
having to take a screwdriver to the amp.

That's impressive.

Paul, W9AC