Copies of the papers presented at, or published for DCC are available in various ways. A paper printed in the proceedings will be available for purchase in most cases in hard copy as the DCC proceedings. It will in most cases also be available as an individual paper in PDF format as a free download via a link below the abstract (where available) It may also be available on CD-ROM. A paper printed in the proceedings may not have been presented at the conference. Also a presentation at DCC may not be in the printed proceedings. In those cases it may be available on DVD, CD-ROM or as a MP3 download. Links to what is available will be on the page specific to the particular year's DCC.
Printed copies are available at lulu.com. The price for the TAPR and ARRL 34th Digital Communications Conference 2015 Proceedings is:
$ 20 US +applicable shipping/handling.
- Chicago, IL
- Steve Bible, N7HPR, Conference Manager
- Local Hosts
- Mark Thompson, WB9QZB
- Kermit Carlson, W9XA
34th ARRL and TAPR Digital Communications Conference
October 9-11, 2015
Unfortunately, all the video links below have been broken by a change of ISP for the host. The following will take you to an index at You Tube. (hint: the episode number in the broken link may help you find the video).
QRPi - A Raspberry Pi QRP TX Shield Design
by Zoltan Doczi, HA7DCD
"Be Smart, Not Strong" this should be the self explaining phrase of the QRP term in amateur radio.
Low power operation is always more difficult than using hundreds or thousands of watts RF power.
But the smile on your face after the first thousands miles long QSO, using portions of one watt is
worth the challenge! QRP enthusiasts instead of spending time and money on increasing power
capabilities of its station prefer a smarter way: to learn about new modulations and coding techniques
and applying them in everyday HAM operation practice.
Nowadays one of the most impressive QRP mode is Joe Taylor, K1JT's  WSPR  (pronounced "whisper"). WSPR stands for "Weak Signal Propagation Reporter". Programs written for WSPR mode designed for sending and receiving low-power transmissions to test propagation paths on the MF and HF and recently UHF bands. Users with internet access can watch results in real time at wsprnet.org
The QRPi board (or shield as referred by the community today) is an inexpensive way of turning a Raspberry Pi single-board computer into a QRP transmitter.
Keywords: QRP, RPi, SDR, WSPR, open-source
VOA Radiogram: Text and Images via Shortwave Broadcasting
by Kim Andrew Elliott, KD9XB
The Internet has largely replaced shortwave radio for the broadcast of news and
information across international boundaries. A growing number of countries, however, are
blocking Internet content from abroad. As a possible workaround, digital text modes familiar to
the amateur radio community can be used to broadcast news via existing shortwave transmitters
and can be received on any shortwave radio, but software is required to decode the text. VOA
Radiogram is a weekly Voice of America program experimenting with text and images through
a shortwave broadcast transmitter
Keywords: broadcasting, HF, shortwave, MFSK
HF Receiver Testing: Issues & Advances
by Adam Farson, VA7OJ/AB4OJ
ARDEN, AMATEUR RADIO EMERGENCY DATA NETWORK
by Andre Hansen, K6AH
Mesh technology has been around for over ten years. Over the past two years developers on the
AREDN. team have advanced the art by porting Broadband-Hamnet.s extremely popular mesh
firmware to the Ubiquiti airMAX line of commercial Wireless ISP routers. This has literally changed
the complexion of mesh implementations from an experimental, hobby-oriented, novelty into a viable
alternative network suitable for restoring some degree of Inter/intra-net connectivity .when all else
More recently, the developers of this software have kicked-off a new project, AREDN, focused on taking this technology to the next level in EMCOMM communications.
This paper begins with an introduction to the AREDN Project and mesh networking and concludes with a roadmap for the Project.s future. It dives into implementation techniques and considerations as well as avoidable pitfalls.
Keywords: AREDN, EMCOMM, mesh, BBHN
Feher Modulation 16 QAM
by Patrick Jungwirth, PhD
We present simulations of conventional quadrature amplitude modulation (QAM) and Feher-QAM to
estimate the bandwidth improvement for Feher-QAM. We show more than a 10% improvement
(reduction) in bandwidth for Feher-QAM over conventional QAM. We also show the power spectral
density for Feher-QAM has a much faster convergence than conventional QAM.
Conventional digital modulation techniques are limited by embedded rectangular windowing functions. Some more advanced modulation techniques utilize raised cosine windowing functions (filters) to improve sidelobes. Feher modulation uses a half cycle raised cosine waveform to reduce bandwidth and improve sidelobe attenuation. Feher modulation offers the equivalent power spectral density convergence of a raised cosine windowing function with twice the width (half the bandwidth). All symbol transitions in Feher modulation are smooth and occur at zero slope points. The smooth, zero slope transitions help improve intersymbol interference, and reduce timing jitter problems.
Key words: Feher modulation, QAM, Feher-QAM
Update on DATV-Express exciter for Digital-ATV
by Ken Konechy, W6HHC
The old technology of analog-ATV suffers from susceptibility to snow and
multi-path ghost images. Digital-ATV (DATV) using new technologies like
digital modulation, and Forward Error Correction (FEC) can result in
robust video reception where analog-ATV fails, as well as providing more
narrow bandwidths on the ham bands. This presentation will review
progress by the DATV-Express Project Team since DCC2014. These new
- Making the exciter more portable by Hardkernel ODROID U3 Single-Board-Computer
- Support of Narrow-BandWidth DATV down to 0.5 MHz
- Using Express_Server software to provide video by UDP
- DatvExpressServerApp software on Windows (no Linux)
- DatvExpressSdrApp software for FM and SSB (no Linux)
- A brief report on the European MiniTiouner USB-based Receiver Project
Measuring the Ionosphere at vertical incidence using Hermes,
Alex, and Munin Open HPSDR and Gnuradio.
by Tom McDermott, N5EG
This paper describes a monostatic method for measuring the vertical virtual height and the vertical
velocity of the F-layer of the ionosphere. The equipment is simple and relatively low power, it uses the
Open HPSDR Hermes transceiver module, Munin broadband Power Amplifier (PA), and Alex RF filter
module. The antennas consist of a 40m dipole and antenna tuner for transmit and an active receive
loop antenna. The software real-time processing (reception, windowing, and correlation) is done using
Gnuradio on a Linux PC, followed by post-processing using a Python program (multiple sweep
integration and plotting).
Key words: Monostatic, Ionosphere, Doppler, Correlation, HPSDR, Gnuradio
Arduino CAT Controller HPSDR
by John Melton, G0ORX/N6LYT
- Abstract: Simple CAT coltroller for HPSDR using an Arduino micro-controller and a few switches and a step encoder.
ARDOP (Amateur Radio Digital Open Protocol)
by Rick Muething, KN6KB, Matthew Pitts, N8OHU and John Wiseman, GM8BPQ
- Abstract: The popularity of low cost PCs and tablets with substantial DSP processing power and an increasing awareness of digital signal processing in the amateur community have created an explosion of digital modes. Some of the challenges this poses are lack of portability, inconsistent .virtual TNC. interfaces and protocols optimized for single uses. ARDOP is a new protocol development which was targeted to address these challenges. The development started in 2014 and Alpha testing of the ARDOP_Win TNC (Windows version) was begun in April 2015. From the beginning the protocol was designed to cover a wide spectrum of amateur uses and be fully documented with open sourced code to encourage learning, experimentation, evolution and portability to other platforms both software and hardware. Key words: ARQ, FEC, 4FSK, 8FSK, 16FSK, 4PSK, 8PSK, WINMOR, cyclic prefix, bandwidth negotiation, automatic timing, open source and sound card protocols.
An OS Independent and Device-Independent Mobile Web Front
Panel for Radio Transceivers
by Bruce Perens, K6BP
by Patrick Prescott, KC1AJT
- Abstract: An in-depth look at mesh networking using repurposed WiFi equipment in FCC Part 97 Amateur Radio spectrum.
OpenWebRX: SDR Web Application for the Masses
by Andras Retzler, HA7ILM
Modulation . Demodulation Software Radio
by Alex Schwarz, VE7DXW and Guy Roels, ON6MU and Omar H. Longoria
Design of a Practical Handheld Software Radio: Part II
by Chris Testa, KD2BMH
- Abstract: The design of a standalone battery powered Software Defined Radio (SDR) is presented. Three rounds of prototypes were designed, built, and tested over the last three years. The hardware architecture of the newest design is detailed, with the goal of getting the device into the field to build real RF links. The software stack, from the high-level websocket user interface down to the embedded Linux operating system are discussed. Finally, the latest work on the Field Programmable Gate Array (FPGA) modem are presented, including optimization work that drastically improves simulation performance.
Software Defined Radio Server
by Phil Theis, K3TUF
SatNOGS: Satellite Networked Open Ground Station
by Daniel J. White, Ph.D., AD0CQ
The SatNOGS, or Satellite Network Open
Ground Stations, project promotes and supports free and
open space applications. It seeks to solve the problem
of connecting many satellite users/observers to many
ground station operators. Modern open software, web,
and hardware techniques are used in implementing the
Network, Database, Client, and Ground Station subprojects.
Modularity in all the systems promotes the
dual-use of ground stations by not interfering with local
operation while utilizing the great amount of time a
civilian, non-commercial ground station would otherwise
Keywords: Terms.SatNOGS, CubeSat, software-defined radio, satellite ground station, open source
The TASS RF Switch
by John Ackermann, N8UR
- Abstract: A High Performance RF Switch for Lab and Hamshack
Bandwidth Requirements for Digital Voice
by Bryan Hoyer - K7UDR
Amateur Radio Voice and Data Network Interconnection
by John Hays, K7VE
- Abstract: BRINGING SANITY TO A DISJOINTED LANDSCAPE
SDRs and Stuff
by Steve Hicks, N5AC
- Phase noise considerations
- The ADC Overload Myth
- Noise Reduction Techniques
- Wideband Noise Blanking
- Digital Voice Modes
- SO2R / Full Duplex
Issues with the Open Hardware Model
by Bruce Perens, K6BP
Ham Radio -- Now What?
by Ward Silver, N0AX
The Saturday Evening Banquet Speaker
3D Modeling for the Radio Amateur
by Steven Bible, N7HPR
The Sunday Morning Seminar
Video of the presentations at the 34th DCC will be available:
Check for availability at: HamRadioNow.tv.