PENELOPE - Companion Transmitter to Mercury
8th Februay 2007 - Update. Block diagram updated to reflect current Breadboard design.
7th February 2007 - Update. Block diagram updated to reflect design feedback. Breadboard built, tested and working. Prototype PCB layout started.
3rd February 2007 - Initial Specification
The Atlas compatible transmitter will use Digital Up Conversion (DUC) techniques and process the I and Q signal from the PC (or Sasquatch DSP board) directly without the need for a sound card.
Some of the planned features include:
1.8 - 55MHz frequency coverage 1W pep output Low level transverter output AM, C-AM, FM, CW, PSK etc RF phase and magnitude outputs for future Envelope Elimination and Restoration (EER) power amplifier Open drain FET for PTT control of external amplifiers Seven open collector outputs for Linear, relay etc control, Solid state antenna changeover relay for fast QSK. Optional on board microphone ADC or use with a Janus card Frequency options: o On board high performance 125MHz crystal oscillator o External 125MHz source o On board oscillator can be phase locked to 10MHz reference e.g. Gibraltar o On board 10MHz OCXO/TCXO option FPGA based DUC enabling future code upgrades USB interface to PC via Ozy board I and Q balanced adjustment not required due to digital generation of RF waveform ADC for ALC or PA linearization etc. ALC processed in the FPGA to avoid delays associated with PC processing
Lyle, KK7P, has kindly agreed to lay out the PCB. Please provide feedback, comments and feature requests via the hpsdr reflector.
A block diagram is shown below.
Update Feb 14 2007: Preliminary Alpha schematic (XA8) for Penelope is here : http://www.hamsdr.com/personaldirectory.aspx?id=503