From HPSDRwiki
Revision as of 06:51, 7 August 2011 by KV0S (Talk | contribs) (Update 7 August 2011)

Jump to: navigation, search

Hermes - A DUC/DDC Transceiver

Hardware block diagram. Click to enlarge.

Project Leader: Kevin M0KHZ

Hermes is a single board Digital Up and Down Conversion (DUC/DDC) full duplex HF + 6m multi-mode transceiver.

It is basically the Mercury, Penelope, Metis and Excalibur boards rolled into one PCB. The board communicates to an associated PC via 100T/1000T Ethernet.

Hermes has the following features and facilities:

  • Uninterrupted coverage from 50kHz to 54MHz
  • Transmit and receiver image rejection > 110dB
  • Full duplex operation, any split over entire 160m to 6m range
  • Future expansion possible to eight independent receivers using the same antenna
  • 500mW RF output on 160 – 6m amateur bands
  • Built-in high performance preamp, with a noise floor typically -135dBm in 500Hz
  • Software-selectable 31dB input attenuator in 1dB steps
  • High performance receiver – same specifications as the HPSDR Mercury receiver (ie Blocking Dynamic Range typically about 125dB)
  • FPGA code can be updated via the Ethernet connection
  • Seven user-configurable open-collector outputs, independently selectable per band and Tx/Rx (for relay control, etc - with sequencing via PC code)
  • Separate open-collector PTT connection for amplifier control, etc, with sequencer
  • Microphone PTT jumper-selectable from tip or ring connection
  • Bias for electret microphones via jumper
  • Four user-configurable 12 bit analogue inputs (for ALC, SWR etc)
  • Three user-configurable digital inputs (for linear amplifier over temperature, etc)
  • Optional in-built switch mode power supply – less than xxxmA (receive) from a 13.8V supply
  • I2C bus connector for control of external equipment
  • Full QSK using the Kiss Konsole software, since digital signal processing is not used in the controlling PC for CW carrier generation
  • Low-level transmitter output for transverter use (0dBm) as well as user-selectable output attenuator
  • Stereo audio outputs at line and headphone levels
  • In-built 1W stereo audio amplifier for directly driving speakers
  • Direct, de-bounced connections for a Morse key (straight or iambic) and PTT
  • 122.88MHz master clock, which can be phase-locked to an internal 10MHz TCXO or external frequency reference
  • Jumper-selectable external frequency reference, with signal processing, to suit numerous GPS-locked 10MHz reference sources
  • Direct ribbon cable interface to Apollo 15W power amplifier, low pass filters and automatic ATU or Alex Antenna switch, HPFs and Tx LPFs
  • Low noise, high efficiency, Switching Power Supply designed by Kjell Karson,LA2NI
  • Ethernet interface supports fixed, APIP or DHCP IP address
  • Hermes responds to ping and ARP requests, auto senses Ethernet cable connection and connection speed

Apollo is a combined 15w PA, Low Pass Filter bank and Automatic ATU. The Apollo project is led by Kjell Karlsen LA2NI.

Hermes and Apollo in enclosure - photo copyright Kjell Karlsen 2010.

Update 7 August 2011

The primary PCB layout team member of Hermes, Abhi has a blog on Hermes at . --KV0S, Dave 06:51, 7 August 2011 (PDT)

Update 7 July 2011

A prototype board has been built and tested. The board is fully functional and meets or exceeds the performance of the Mercury/Penelope/Metis/Excalibur boards the design is based on.

Some minor board layout issues are currently being addressed and a pre-production layout is presently being prepared. The KD5TFD and W5WC versions of PowerSDR(TM) as well as KISS Konsole have been modified to provide native Hermes support.

Ken, N9VV, has a lot of information regarding Hermes on his web site here

(click for larger image) photo courtesy Abhi Arunoday