Embed Size (px)
DESCRIPTION
Radio Technology, and radio frequency
Citation preview
TAPR:Tomorrow’s Ham Radio
Technology Today
John Ackermann, N8URTucson 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:[email protected] or [email protected]://www.febo.com01 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 RoadTucson, AZ 85749-9399 USA01 940 [email protected]://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:– [email protected] (APRS)– [email protected] (Packet Networking)– [email protected] (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 DiagramSoftware Defined Radio
VariableFrequencyOscillator
LocalOscillator
(fixed)
Antenna
BandpassFilter
RF IF Baseband
ADC/DACDSP
Block DiagramBlock DiagramSoftware Defined RadioSoftware Defined Radio
LocalOscillator
(fixed)
Antenna RF IF Baseband
DSPADC/DAC
Block DiagramBlock DiagramSoftware RadioSoftware Radio
Antenna RF IF Baseband
DSPADC/DAC
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, W7PUAQST - Sep, Oct, Nov 1999
http://www.proaxis.com/~boblark/dsp10.htm
http://www.arrl.org/tis/info/vhfproj.html
• R2-DSP by Rob Frohne, KL7NAQST - Apr 1998
http://www.wwc.edu/~frohro/R2_DSP/R2-DSP.html
• A Panoramic Transceiving System for PSK31by 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 byErnie Manly, W7LHL
TR SW(D2)
U1,U2
TR SW(D1)
U4,U5
Synthesizer124.3 to 128.4 MHz
5 kHz Steps
Synthesizer19.680 MHz
TR SW(U11A,U11C)
Q1,U10A
ADC 90o
Arc TangentFM Detector
Sinewave BFO12.5 -17.5 kHz
90o
SW
+ / - AGC
AudioFilters
LMSDenoise
DAC U14
FFT SpectrumAnalyzer
FMSquelch
SSB and CWDetector
Analog Devices EZ-Kit Lite
Speaker
Serial Datato PC
1024 Points
AudioPower Amp
IF Amp
50 dB
ANT orXVRTR
R
T
R
T
143 - 149 MHz
150 MHz
2-PoleLC Filter
Low-PassFilter
40 dB
TransmitRF Amp
ReceiveRF Amp
32 dB143 - 149 MHz 19.665 MHz
FirstMixer(U3)
SecondMixer(U15)
28 kHz
Low-Pass Filter4-PoleCrystal Filter
4-PoleLC Filter
TRSW
(U11B)
U109B,Q5,Q6
IF Driver
TR SW(U12A,U12B)
Microphone
R
T
T
R
R
PTT
CW Key
10 MHzExt. Ref.(Optional)
10-20 kHz
J212
J213
J211
J102
J103
J201
J204
Receiver Second IF10-20 kHz
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 QSOW7SLB 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
