TAPR:
Tomorrow’s Ham Radio
Technology Today
John Ackermann, N8UR
Tucson Amateur Packet Radio, Inc.
Who am I?
• A ham for 25+ years (ex-AG9V, WB9OWI)
• A lawyer by trade, working for NCR Corp.
• Active in DXing and Contesting, but
became interested in packet radio, joined
TAPR, and never looked back
– Board member and VP since 1995
– Elected President in 2000
• Contact Information:
jra@febo.com or n8ur@tapr.org
http://www.febo.com
01 937 445-2966
What is TAPR?
• Founded in Tucson, Arizona in early 1980s;
quickly became an international
organization
• Today, over 2000 members worldwide
• Contact Information:
8987-309 E. Tanque Verde Road
Tucson, AZ 85749-9399 USA
01 940 383-0000
tapr@tapr.org
http://www.tapr.org
Previous TAPR Projects/Products
• TNC-1 -- the project that started it all
• TNC-2 -- the “standard” TNC
– OEM’d by AEA, MFJ, PacComm, and others
• TrakBox (satellite antenna tracker, with
AMSAT)
• DSP-93 (early DSP modem)
• 9600 Baud Modem
• Many Others
TAPR Today
• Focused on “Enabling Technology”
– Tools that let hams continue to be on the
leading edge
• Major Projects:
– FHSS Spread Spectrum Radio
– Software Defined Radio
– PIC-based Project Kits
• Co-Sponsor (with ARRL) of the annual
Digital Communications Conference
Current Products
•
•
•
•
•
PIC-E -- Universal Packet Radio Encoder
T-238 -- One-Wire Weather Station
Compact Flash Adapter II
Totally Accurate Clock
METCON-2 -- Universal Remote
Control/Sensor
• EZ-Trak -- New Generation Satellite
Antenna Tracker
Books and Publications
• PSR -- TAPR’s Quarterly Journal
• DCC Proceedings
• Wireless Digital Communications: Design
and Theory by Tom McDermott, N5EG
• Networking Without Wires: TCP/IP over
Amateur Radio by John Ackermann, N8UR
• Spread Spectrum Update edited by Greg
Jones, WD5IVD and Steve Bible, N7HPR
TAPR’s Online Presence
• http://www.tapr.org
• Mailing lists:
–
–
–
–
aprssig@lists.tapr.org (APRS)
netsig@lists.tapr.org (Packet Networking)
ss@lists.tapr.org (Spread Spectrum)
Many, many others
• File Downloads
– APRS software, etc.
What Is a Software Defined Radio
(SDR)?
Performs the majority of signal processing in the
digital domain using programmable DSPs and
hardware support, but some signal processing is still
done in the analog domain, such as in the RF and IF
circuits.
What Is a Software Radio (SW)?
The ultimate device, where the antenna is connected
directly to an A-D/D-A converter and all signal
processing is done digitally using fully
programmable high speed DSPs. All functions,
modes, applications, etc. can be reconfigured by
software.
Why Software Defined Radios?
• Dale Hatfield, WØIFO,
Chief, Office of Engineering and Technology,
Federal Communications Commission
“This could stimulate a whole new generation of
amateur innovation that not only includes the
more spectrally efficient systems I mentioned
earlier, but also radios that could adapt to their
environment as well.”
Speech to AMRAD’s 25th Anniversary Dinner June 17, 2000
http://www.fcc.gov/Speeches/misc/dnh061700.html
Benefits of SDR
•
•
•
•
Flexible
Reduced Obsolescence
Enhances Experimentation
Brings Analog and Digital World Together
New Breed of Radio
•
•
•
•
•
Reprogrammable
Multiband/Multimode
Networkable
Simultaneous voice, data, and video
Full convergence of digital networks and radio
science.
Block Diagram
Software Defined Radio
Antenna
RF
IF
Bandpass
Filter
Variable
Local
Frequency Oscillator
Oscillator (fixed)
Baseband
ADC/DAC
DSP
Block Diagram
Software Defined Radio
Antenna
RF
Local
Oscillator
(fixed)
IF
Baseband
ADC/DAC
DSP
Block Diagram
Software Radio
Antenna
RF
ADC/DAC
IF
Baseband
DSP
Looking Ahead
• Smart Radios that configure themselves to
perform the communications task requested (using
different frequency bands, modes, etc.)
• Cognitive Radios that learn about their
environment (e.g., other users nearby, interference,
location, elevation) to optimally configure
themselves to maximize efficiency and reduce
interference.
Technical Challenges
• Dynamic Radio
• ADC/DAC Speed
• Smart Radio Algorithms
How to Build a SDR
• DSP-10 by Bob Larkin, W7PUA
QST - Sep, Oct, Nov 1999
http://www.proaxis.com/~boblark/dsp10.htm
http://www.arrl.org/tis/info/vhfproj.html
• R2-DSP by Rob Frohne, KL7NA
QST - Apr 1998
http://www.wwc.edu/~frohro/R2_DSP/R2-DSP.html
• A Panoramic Transceiving System for PSK31
by Skip Teller, KH6TY and Dave Benson, NN1G
QST - Jun 2000
http://www.arrl.org/tis/info/psk31.html
(see also the new 80M “Whistler” radio by the same folks)
The DSP-10 As a SDR
DSP-10
Constructed by
Ernie Manly, W7LHL
143 - 149 MHz
Receive
RF Amp
Synthesizer
124.3 to 128.4 MHz
5 kHz Steps
Synthesizer
19.680 MHz
10 MHz
Ext. Ref.
(Optional)
U1,U2
R
ANT or
XVRTR
TR SW
(D2)
J211
J212
T
2-Pole
LC Filter
32 dB
150 MHz
Transmit
RF Amp
143 - 149 MHz
R
19.665 MHz
T
4-Pole
LC Filter
J213
First
Mixer
U4,U5
Low-Pass
Filter
R
Receiver Second IF
10-20 kHz
TR SW
(U11A,U11C)
(U15)
T
U109B,
Q5,Q6
10-20 kHz
Audio
Power Amp
Audio
Filters
o
90
TR
SW
(U11B)
DAC
R
ADC
o
90
SSB and CW
Detector
+/-
AGC
R
LMS
Denoise
Sinewave BFO
12.5 -17.5 kHz
J102
FFT Spectrum
Analyzer
PTT
CW Key
Low-Pass Filter
IF Driver
50 dB
Microphone
Second
Mixer
40 dB
Q1,
U10A
T
4-Pole
Crystal Filter
(U3)
IF Amp
TR SW
(U12A,U12B)
28 kHz
TR SW
(D1)
J103
Arc Tangent
FM Detector
SW
FM
Squelch
Analog Devices EZ-Kit Lite
1024 Points
J201
Serial Data
to PC
U14
J204
Speaker
QRP 5-Watt 1296 EME QSO
On 25 February 2001 Ernie, W7LHL, and Larry, W7SZ, were successful with a PUA43 mode
QSO on 1296 MHz EME (Moon bounce). They were using a QRP power level of 5-Watts and backyard TVRO dishes of 10 and 12 feet.
Copy was Q5 as can be seen on the screen at the left (click on it for a bigger version). They were using a 28 character setting on PUA43 (see
below for more information on the PUA43 mode). The extra characters were being used for redundancy in portions of the message. The
message would begin to appear in a few minutes, but Q5 copy was taking roughly 15 to 30 minutes per message. They exchanged call signs,
grid squares, and confirmations both ways. Copy at W7LHL was not quite as good as for the other direction, but both stations received a
complete message in the 28 characters. This was their first attempt at using the 5-Watt level for a QSO. As was reported earlier they had
been successful at higher power during January.
None of those involved are aware of any previous 5 Watt 1296 MHz EME QSO's although this may well have been done using larger
antennas. Any information on this would be appreciated.
The PUA43 mode described below is ideal for this type of work. The limits of signal strength have yet to be fully explored. Both Ernie and
Larry reported that they were kept busy with antenna pointing and playing screen "anagrams," so were not sure what their patience level
might be if the power kept dropping. The nature of the mode is to trade-off time for increased sensitivity.
Single Yagi, 150 Watt 2-Meter EME QSO
W7SLB and W7PUA demonstrated a QSO on 2-meter EME, using the PUA43 mode of the DSP-10. Single Yagis and transmitter powers of
150 Watts or less were used on both ends of the contact. Details are available on the weak signals page and the linked text