Here you will find brief summaries of presentations from past MARC meetings, with slides, photographs, or other material from the meeting. If you missed a meeting, and want to know more about what went on, this is where you can find out. If you presented at a meeting, and want to share your information more widely, contact Ben Tovar with the information you would like to see posted.
October 28, 2016: Intermidiate Frequency (IF) Filtering
Ethan presented the basic principles on IF, and how it is used in receivers.
September 30, 2016: Emergency preparedness
Presented by: Brent Walls, N9BA
Brent Walls, the newly elected ARRL Section Manager for the state of Indiana, did a presentation on . Brent will be doing a presentation on emergency preparedness, including the interactions of various response groups.
August 26, 2016: Tropospheric Ducting
Presented by: Gordon West, WB6NOA
Gordon West gave a very engaging introduction on Tropospheric Ducting via Skype from his station in Southern California. As Gordon related, tropospheric ducting is a weather related phenomenon that tends to occur on June to August when both the temperature and humidity is high, but there is no wind. This changes the air refraction index which allows VHF and UHF (and sometimes even microwaves) to travel thousands miles, rather than their maximum usual of hundreds of miles.
Gordon showed us radio contacts on 2 meters from Souther California all the way to Hawaii (2,500 miles) on FM and SSB/morse-code beacons.
For more information:
April 29, 2016: VHF/UHF Dual Band J-Pole
Presented by: Ed Fong, WB6IQN
Prof. Ed Fong presented his design on a dual band VHF/UHF J-Pole, via conference call. Thank you Ed for the most engaging presentation! For more information on Ed's antennas you can consult the ARRL Antenna Handbook, or visit his webpage .
January 29, 2016: Summits on the Air activations
Presented by: Barry Keating, WD4MSM
Barry Keating gave us a great presentation on his Summits on the Air activations in Rocky Mountain National Park and the town of Estes Park, CO with a follow-up about marine radio technology and its relation to amateur radio.
November 28, 2014: Amateur RF Modulation
Ethan presented some high-level theory on RF modulation for Amateur service, starting with CW and ending with modern digital modes. Slides are available here and much more information on the subject can be found in the ARRL Handbook and other texts.
September 26, 2014: Automatic Packet Reporting System (APRS)
Presented by: Bob Bruninga, WB4APR
Bob gave an updated version of his Dayton Hamvention 2014 talk on APRS to the MARC members in attendance via conference call. He stressed the importance of human-to-human communication in APRS's mission and discussed the various advanced features of APRS that are available to the modern ham, including features accessible from a standard HT or mobile radio without dedicated APRS features. His slides are available here in PowerPoint format.
May 30, 2014: DVB-T Dongles for Amateur Radio
Presented by: Alton Floyd, W8ADF
Al showed us a variety of uses for cheap USB DVB-T television tuner dongles in amateur radio and spectrum monitoring, including hardware assists and software packages. His slides are available here, and they include links to interesting software and resources.
January 31, 2014: DIY Stealth Antennas
Presented by: Jean-Paul Louis, AC9GH
Jean-Paul gave a presentation on small antennas that can be easily concealed but provide excellent performance. His presentation covered slim jim antennas for 2 meters and magnetic loop antennas for HF. Physical construction, matching, radiation patterns, and mounting techniques were discussed.
Slides from his presentation are available here