HERMES
Hermes - A DUC/DDC Transceiver
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.
Update 7 August 2011
The primary PCB layout team member of Hermes, Abhi has a blog on Hermes at HPSDR Hermes .
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 http://www.n9vv.com/hamradio.html
