UDRX Update

Dayton Hamvention 2015
Dennis recently completed the Software Defined Receiver for the UDRX-440.  It now goes to Basil for integration with our framework.

This is a complete general purpose software defined receiver with a socket interface to support multiple protocols.   AGC is implemented in hardware as there is no conventional FM limiter which would prevent us from implementing other modulations. The MSK receiver utilizes dual software PLLs to implement Mark and Space separately allowing us to track not only carrier error but frequency shift as well. Lock times for a 100Hz frequency error are on the order of 15 mSec or about one and a half characters at 9600, reducing training time for TX/RX switching. There is a separate debug socket for reporting modem state suitable for advanced diagnostics. The fixed point DSP receiver uses less than 10% of available CPU cycles.

When combined with the previously implemented software designed transmitter, we now have a complete SDR transceiver.

The transmitter PA is now running at full power and initial thermal evaluation shows that we have met our goal of 100% duty cycle in a 20C shack without a fan. A separate temp-controlled fan kit will be available for high ambient temperature, continuous duty applications. Spurious emissions are less than -60 dBc.

These are the last significant milestones for the UDRX. Once integration and characterization are complete we will move the UDRX into Pilot Production on the full manufacturing line for field testing.

If you are at Hamvention, please come by our booth (EH0515) and visit with Bryan and John — we are thrilled to have reached this point.