Topband: DSP-based technology

[K4IQJ]

I have implemented full beam steering on my receiving four square array 
using DSP.
At the moment the antennas are four DX engineering receiving verticals
feeding an USRP. (Universal Software Radio Peripheral from Ettus Research 
(www.ettus.com).
The USRP can handle up to four antennas, each digitized at 64 MSPS.
It is definitely not yet ready for prime time, but the basic USRP code
(gnuradio based) is running.  I can steer the array, peak or null signals
etc.  The phase and gain of each antenna can be adjusted separately or they 
can all be moved in tandem to
steer the complete array.  The next step is to add RF amplification ahead of 
the USRP.

I still have a long way to go to get the full system running in a user
friendly manner and then to be able to integrate it into the rest of the
radio system.

Dick, K4IQJ