High Performance Software Defined Radio

An Open Source Design


License NCL
Author John, AJ6BC


Themis - GPS-disciplined Frequency Standard


About the Themis Module

Themis is an HPSDR GPS_disciplined_oscillator (GPSDO) design that is an experimental approach for disciplining Crystal Oven (OCXO) OCXO's and provides 1PPS, 10MHz, and GPS Timestamping to the Atlas Bus for the HPSDR System. Two OCXO's are currently supported - the MTI-Milliren 270 and the MTI-Milliren 220. An on-board DSP provides the disciplining algorithms plus will allow experimentation with custom algorithms. The GPS engine is the LEA-6T from u-Blox. Themis plugs into Khronos as an option to the other GPSDO options.

A Block Diagram is available at Block Diagram

Themis layout

Project leader is John, AJ6BC.

Link to Wiki

Our HPSDR Wiki will contain the latest news, links, files, etc. for Themis. Here is the direct link to the HPSDR Wiki: THEMIS