Presentation Abstracts

Cables and VSWR

Pete, WV3S
pmhiltz@gmail.com

In response to a misunderstanding of the effect of cable length on Standing Wave Ratio (SWR), this presentation uses mathematics and the Smith Chart to demonstrate the effects of cable length on impedance and SWR and demonstrates why not all antennas, at all frequencies, can be tuned to a 1:1 ratio.

If you’d like this short talk for your group, please contact the author.

Length: 13 slides, 30 minutes
Medium: Open Office Presentation


Gamma Matching Part 1

Pete, WV3S
pmhiltz@gmail.com

This talk describes the process of designing a gamma match based on the electrical model of the match as a shorted transmission line composed of the antenna and parallel rod, in parallel with the impedance of the dipole transformed through the same transmission line. It discusses the model and the process, given the physical parameters of the design as input, of calculating the input impedance and establishes the need for a matching capacitance.

The talk gives the needed mathematics and whenever possible, uses both mathematics and the Smith Chart to determine the needed capacitance. Matlab software is shown that automatically identifies the distance to the short that gives an impedance of 50 + jX Ώ and calculates the required capacitance to cancel the antenna’s inductive impedance component.

Part 2 will present the results of using this process to build a 52 MHz horizontal dipole.

If you’d like this short talk for your group, please contact the author.

Length: 27 slides, 45 minutes
Medium: Open Office Presentation


Gamma Matching Part 2

Pete, WV3S
pmhiltz@gmail.com

This talk describes the application of the theory of Part 1 to build a 52 MHz horizontal dipole.

If you’d like this short talk for your group, please contact the author.

Length: 27 slides, 45 minutes
Medium: Open Office Presentation


Using the MFJ 269 Antenna Analyzer

Andy, WO3L

This talk discusses the use of the MFJ 269 Antenna Analyzer.  Included is information about its principle of operation and some of the limits on its use.

Length: 13 slides, 30 minutes
Medium: Open Office Presentation


Station Building

Jim, WX3B

This talk summarizes considerations such as local terrain, choice of antennas, HF rigs and power as you consider building / enhancing your HF station.
Length: 45 minutes
Medium: Microsoft PowerPoint

Unusual Antennas for Diverse Circumstances

Curt, WB8YYY

While coax fed dipoles, verticals and Yagi antennas are the most common radiators – there are many other viable antennas that can be used. While a very high end station may only use these common antennas – many smaller stations can consider the benefit of these other antennas. There are circumstances where effective antennas need not be resonant, center fed or constrained to only one or a few bands. An enterprising ham – whether operator portable or at their home station should consider these alternatives. An effective antenna must fit (a) space available, (b) budget, (c) preferences and (d) laws of physics. Today’s amateurs are radiating effective signals with a variety of antennas.


WSPRlite & Antenna Testing

David, AA3DA

A short presentation on WSPRlite and how it works and what my results have been. This is the little package sold by SOTABEAMS. Fascinating instant reports on propagation from the little 200 milli watt coded WSPR transmission.


Portable Stations

Mark, W3MSR

Portable equipment indicates a configuration that allows for relatively rapid collection, transportation, and deployment of amateur radio gear. This talk is about non-fixed stations in the field. Mobile stations of various types is a topic for another day.


Basics of 3D Printing

Chet Andes, Carroll Community College

A discussion of 3D printing with a focus on the basics along with information about courses taught by CCC on the topic.


Terrain Mapping for Antenna Performance

Jim, WX3B

Have you ever dreamed about finding that perfect property for High Frequency (HF) operation for Amateur Radio?
Please join Jim Nitzberg, WX3B as he describes 3 extremely useful tools that work together to quickly give you an evaluation
of a given GPS location.  Gone are the days of using paper topographic maps, or even using MicroDEM and joining electronic maps together.
Dean Straw, N6BV provides High Frequency Terrain Analysis (HFTA) – a free application sold with the ARRL Antenna Book.
Google Inc provides Google Earth (We have all used that application, right?)
…AND…
Stu Phillips, K6TU provides www.k6tu.net, a service that has been available now for several years, with FREE TERRAIN files for use DIRECTLY with HFTA.
NOTE:  Stu’s web site provides optional HFTA sweep modeling and VOACAP predictions in real time for a very small yearly contribution.
Jim will illustrate how to use these 3 tools together, and how to interpret what the results of HFTA are telling you about specific geographic locations.  Jim’s presentation can be found here.

Printed Circuit Board Design

Al Grasley

A discussion of printed circuit board design and creation.


National Traffic System

Chris, AB3WG

A discussion of the National Traffic System.


Army MARS

Mark, N4EOC

History and current operations of the Army Military Auxiliary Radio System.


Stealth Antennas

TBD

Discussion of stealth antenna for those who are space limited.


No Strain Shack Tour

Andy, WO3L

A pictorial tour of club hamshacks.


Club Review

Pete, WV3S

A discussion of the Club’s ByLaws, changes made in the past year, business processes, loaner equipment, and other topics designed to inform the membership of how the Club operates.

Length: TBD
Medium: Microsoft Powerpoint Presentation


 

High Power SW Transmitter Tour

Fred, K3TAZ

In February of 2018 I was given a tour of the transmitter site for WRMI – Radio Miami International. The slide show has pictures of some of the 23 antennas on 660 acres and also shots of storm damage caused by last seasons hurricanes. The presentation includes a brief discussion of the 4CV100,000 RF power tubes and transmitter maintenance. Work shop areas are shown as well as transmission lines used for high power HF broadcasting. Audio processing equipment is discussed, for use in the unique environment of the shortwave spectrum.

Length: TBD
Medium: Microsoft Powerpoint Presentation