Topband: Direct down conversion HPSDR transceiver kit

[Steve Ireland]

G'day

 

As some on this reflector will know, Greg ZL3IX and I both use High
Performance Software Defined Radio or 'HPSDR' transceivers on 160m, which
have direct down (rx) and direct up (tx) conversion SDR architectures.  This
is the architecture chosen by FlexRadio for its new 'Signature' range.

One of the problems for those lowbanders who are interested in trying the
HPSDR has been the difficulty in obtaining all the necessary PCBs.  This has
now been got round by the introduction of a single board full-duplex
multi-mode transceiver board called the Hermes, which covers 160m to 10m and
is available from the Tucson Amateur Packet Radio Group (TAPR) -
<http://www.tapr.org/kits_hermes.html> http://www.tapr.org/kits_hermes.html.
Hermes is basically the Mercury <http://www.tapr.org/kits_merc.html> ,
PennyLane <http://www.tapr.org/kits_PL.html> , Metis
<http://www.tapr.org/kits_metis.html>  and Excalibur
<http://www.tapr.org/kits_excalibur.html>  HPSDR boards rolled into one and
communicates to an associated PC via 100T/1000T Ethernet. 

For those lowbanders who like 'bleeding-edge' radio, Hermes has the
following features: 

*	Supports 7 fully independent receivers (sharing the same antenna -
and with suitable PC software) 
*	Each receiver can display 48/96/192kHz of spectrum 
*	Blocking Dynamic Range about typically 125dB) 
*	Transmit and receiver image rejection > 110dB 
*	Transmitter two-tone 3rd order IMD of -50dBc on 20m @ 400mW output 
*	500mW RF output on 160 - 10m amateur bands, 350mW on 6m 
*	Built-in high performance preamp, with a noise floor typically
-135dBm in 500Hz 
*	Software-selectable 31dB input attenuator in 1dB steps 
*	Full QSK operation (performance dependant on associated PC and
control software) 
*	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 
*	Low phase noise (-140dBc/Hz @ 1kHz at 14MHz) 122.88MHz master
clock,which can be phase-locked to an internal 10MHz TCXO or external
frequency reference 
*	Direct ribbon cable interface to Apollo
<http://openhpsdr.org/wiki/index.php?title=Apollo>  15W power amplifier, low
pass filters and automatic ATU or Alex <http://www.tapr.org/kits_alex.html>
Antenna switch, HPFs and Tx LPFs 
*	Ethernet interface supports fixed, APIP or DHCP IP address 

Vy 73

Steve, VK6VZ