Misc Archive information

“RF IMPEDANCE AND THE SMITH CHART”

• Resistance & Reactance (capacitance/inductance) >>> Impedance /Reflection coefficient and SWR
• Relation between impedance and reflection coefficient / Impedance mapped onto a polar graph
• Constant resistance circles, constant reactance arcs (circles) / SWR circles, rotation along a 50-ohm transmission line
• Open-source, cross-platform RF/Microwave software for learning/experimenting: QUCS http://qucs.sourceforge.net
• Example impedance calculations at either end of the feedline / Impedances of an approximate 40 m dipole at 20 m and 17 m
• Simple matching circuit calculation for the non-resonant 40 m dipole that could allow 17 m operation.

Amateur Radio at Microwave Frequencies: Hands-on equipment and concepts demonstration of getting on the air at UHF and above. “You will be surpised at how little it takes to get into microwaves. You can build a rig for less than $200.”

Example components:

• discarded satellite TV dish / mixer (~$50) / stable frequency source module (~$50?)
• power supply for freq. source module (requires -20V @ 1.5 amp) / Your existing VHF/UHF SSB transceiver for use as an IF section, or even a 10m rig could be used.

Concepts discussed and demonstrated:

• rectangular waveguides vs. coaxial cables or twin-lead t-lines
• polarization
• near-field and far-field regions in the vicinity of an antenna or aperture
• power units Watts, milliwatts, dBm, dB, orders of magnitude, signal levels
• standing waves
• reflective materials, lossy dielectric materials
• cut-off freq. in waveguides
• microwaves behaving like light rays
• parabolic dish antennas with very high gain and small beam-width
• interesting propagation effects/unexpected communication paths

Space Weather and its affect on radio propagation. Rob is a Senior Master Sergeant in the United Sates Air Force assigned to Space Weather at NOAA. Rob recently relocated to Colorado from Dayton, Ohio (yes, he knows all about Hamvention).

Removed broken Link Aug 2020 Jerry N0OUW

Robert Steenburgh (KA8JBY) did the October presentation at the club. He wanted to share this solar hurricane with us.

Audio Engineering.
Ray’s company maintains the sound equipment for the US House & Senate chambers in Washington D.C.
Did you ever wonder how echoes are handled in stadiums? Come find out.
http://www.soundfirst.com/

Digital modes and radio control with Ham Radio Deluxe (software)

Wayne Smith – N0LEA will present. More info about the software at: http://hrd.ham-radio.ch/

Alternative power, including solar cells.

Dave has a cottage 15 miles from the nearest power.

Learn how Dave provides all his energy needs from solar cells & batteries, a small generator and propane.

These topics apply to Shack-in-a-Box phase IV.

Surprise presentation on the Hoover Dam. – ; (Broken Link Removed 3/9/20 N0OUW)

Dan was in town visiting his brother Jim (N0IRK) and agreed to show us where he works.

Rich brought show & tell – a base station using an HT. Often times a new ham only has an HT as their first radio

Field Day preparation: How to use the club’s new IC7000. Download the manual. Rmoved Broken Link 

Aug 2020 Jerry N0OUW

Amateur Rockets and Radio watch this presentation.

Thanks Dan (W3ETA) for converting this presentation to a web format.

Christmas Party

Pirates in the Caribbean – BVI sailing

Christmas Party

Tiger Cruise – US Navy

Sebastian NS0W

Chris K8CRM