Transcript Using New Technology for Improved CW and SSB EME

Software Defined Radios
A Contester’s Perspective
by
Bob Wilson, N6TV
[email protected]
With thanks to
Jeffrey Pawlan, WA6KBL
Ilberto di Bene, I2PHD
Visalia DX Convention
Contest Forum
April 26th, 2008
This is not a technical talk
 I will not try to explain how SDRs
work
 I will try to show how they could
be used by contesters
What you will see
 Brief overview of some available
SDR hardware
 Demo of WinRad software, by I2PHD
 The “Waterfall display”
 Demo of CW Skimmer by VE3NEA
 An SDR on the Web
 Implications and Discussion
Softrock-40
Softrock 6.1
RFSpace SDR-IQ
Microtelecom Perseus
(used to make demo recordings)
FlexRadio Flex-5000A
FlexRadio Flex-5000C
How to add an SDR “Band Scope” to
your current transceiver


Feed IF out to an SDR tuned to IF freq.
- or Share your transmit antenna with an SDR
receiver
1. Connect “Rx Ant Out” to input of a 2-way Power Splitter


Output 1  SDR’s “Antenna” connector
Output 2  Rig’s “Rx Ant In”
2. Press “RX ANT” button


Rig’s T/R circuit protects SDR front end
QSK works fine
WinRad demo
 Playback of a 10 min. recording made with a
Perseus SDR
 Captured low end of 20m (~ 122 kHz wide)
 Antenna: 5 ele 20m yagi, 42’ boom
 Instructions at http://www.kkn.net/~n6tv
– WinRad Software: 1.4 MB
– Recording: 300 MB (zipped!)
Advantages of the “Waterfall”
Display
 Scan a band with your eyes instead of your
ears
 You can see faint signals and “new” signals
 You can find “holes” where you can call CQ
– Or call in a pileup
 Clicking is faster than turning a knob
 Significant improvement over legacy “band
scopes”
CW Skimmer Demo
 CW Skimmer running in “3 kHz mode”
 With a compatible SDR, you could watch up
to 96 kHz of a band with CW Skimmer
CW Skimmer
 CW Skimmer = Code reader + bandscope
 Simultaneous decoding of multiple channels
 Another program can take CW Skimmer
output and feed it into your contest software
“bandmap” window
– Or automatically post packet spots to a remote
cluster (e.g. N4ZR)
An SDR on the Web
 40 and 80m remote SDR in the Netherlands
 http://websdr.ewi.utwente.nl:8901/
 Note: contest rules generally prohibit the
use of remote receiving sites, even for M/M
– They are not within the property limits / 500m
circle
– They are not spotting nets
– They are not a “remote base”
 But great for “testing propagation”
The CW Skimmer Controversy
 Can single-ops legally use a local CW
Skimmer in a contest?
– Code readers are not prohibited
– Band scopes are not prohibited
– A local CW Skimmer is not a spotting net
– Nothing in ARRL rules seems to prohibit it
– CQ WW rules may prohibit it if K3EST says CW
Skimmer counts as “other DX Alerting
Assistance”
Editorial Opinion
 CW Skimmer represents a major advance in the
radio arts
 It is far from perfect – banning them now seems
premature
 Let the radio arts advance
 We never banned tape recorders, memory keyers,
computer sent CW, computer logging, super check
partial windows, pre-fill databases, code readers,
band scopes, etc., so what’s the big deal?
Remember the Turbine-powered
car?
 Built by Andy Granatelli of STP
 Entered in 1967 and 1968 Indy 500
– Driven by Parnelli Jones, Joe Leonard
 Almost won both races
 Never “banned” outright but …
– So outclassed everything else that USAC reduced the
allowable intake area sufficiently to strangle the engines
and render them non-competitive.
 Should we write rules that stifle innovation?
What you just saw
 SDR hardware
 Demo of WinRad and the “Waterfall
display”
 Demo of CW Skimmer by VE3NEA
 An SDR on the Web
 Still missing: integration of SDRs
with contest software
What’s Next?
 RTTY Skimmer? SSB Skimmer?
 A “robot” – a totally automated op?
– “Z80 OP” – developed by N6TR, in 1986!
 Let’s sponsor an “X-Prize”
– First totally automated op. to make Top Ten box
in the CW NA Sprint
 Competition encourage advancements in
the radio arts
– Don’t write rules that stifle innovation
Discussion