Amateur Radio (Page 2)

Ham Radio, Hobby Projects related to Communications.

An Amateur Radio Enthusiast from Brazil. JK De Marco. In these pages Hams will find his ideas on QRP, Antennas and Complete circuits.

PY2WM JK De Marco Projects

 A 40 dB RF Attenuator

A 40 dB RF Attenuator

“To measure power of a high power transmitter, or to be able to observe the output signal on an oscilloscope or spectrum analyzer, it is necessary that the signal is attenuated in accordance with the instrument, while it must be ensured that the transmitter is “seeing” the correct impedance. So it requires an attenuator that works with three ports (input, output, and output attenuated), all while maintaining the correct impedance of 50 ohms.

The circuit assembly and is shown here in EMRFD and also in the QST. When properly calibrated can be used for precision measurements in section 0-500 MHz, or a a calibration capacitor C1, can be used for the range of 0-50 MHz with reliability.”

Other Projects and Ideas

  • Simple Homebrew Coil Winding Machine
  • Qrp-Br Spectrometer
  • Simple ESR meter
  • Swr Power Measuring mW To KW
  • 5 Volts Reference Voltage Calibrator

A firm based at Greenbackville, Virginia provides parts and kits for Amateur Radio applications. Products include data and audio cables for APRS and packet radio. They also offer simple serial communications testing and monitoring tools.

RPC Electronics – Amateur Radio Supplies

Emergency Vehical Flasher

A spinoff of the original LED chaser. It’s based on the PIC16F84 clocked at 10MHz. This is a basic model that can be adapted to many applications. They are much brighter and can be seen during the day better.

PIC Projects by ke4nyv

PIC Projects by ke4nyv

My Start as a Ham – Ralph’s Story – “I suppose my interest in things electrical began when at a very young age I poked a metal hairpin into an electrical outlet. To this day, I vividly remember the amazing flash and bang that resulted! Of course, I wanted to know why that happened. It was a few years more before I learned to read, and found out about electricity.”

Ham Shack of W5JGV – Ralph

Ananth Notes- Thank god you survived to tell the story, this was a Jolt of a start. Very few people survive this. I would like to add …

All Mains Inlet Sockets should be Shuttered, so that such a thing does not happen again to any child again. Another Law, No Mains Socket should be less that 5 feet above the ground level.

Then we should all move to a 24V home voltage standard, Read more at my Tech blog..

EMerge Alliance – Safe Low-voltage Power

Then ralph has many projects with educative information. A RF Ammeter the Easy Way. A 400 Watt 60 Hertz Power Inverter. These are interesting to study.

Experimental KW HV Switching Power Supply

A KW Switch Mode Regulated High Voltage Power Supply

The design of switching supplies is a bit more involved than traditional “big iron” transformer power supplies. When taken step-by-step, however, it is quite possible for an amateur to design and build a working high power switching power supply. This article describes a high power, high voltage switch mode power supply designed to operate a KW level RF power amplifier.

Home brew Litz Wire

The Litz wire was fashioned by taking two parallel strands of #18 AWG wire about 115 feet long and twisting them together in a clockwise direction with an electric drill until the twisted wires had about two turns per inch. The twisted wire was then cut into four equal length and laid side by side.

Amateur Radio Station operated by Maerin Bancroft. The Online Website includes a Technical section with drawings and building instructions for many projects.

G8NQN – Martin – Keadby North Lincolnshire UK

He has links to various sites that cover the RAE exam theory in detail, this section can be used as a reference for those taking the RAE at a training centre. e old 1/4 inch real to real tape machines

See also – Components Symbols and Pinouts

“In the early 70’s while still working as an electrical engineer, and as a Dj in the evenings I was given the opportunity by a Dj friend to visit the then new BBC Radio Leeds, they wanted anyone interested to go out with recording equipment and collect interesting stories on a freelance basis, both my friend and I where keen and during the following evenings and weekends we would get together and visit youth clubs etc, collecting news and interviews returning them to the studio’s and editing them, yes on the old 1/4 inch real to real tape machines ..”

Technical Backround pf Lucky Martin

John Owen has made Enriching Electronics Pages at vwlowen.co.uk. There are many Ham Radio projects too.

Amateur Radio and Calculators for Electronics

A highlight is the “Build A PICAXE Weather Station.” This is quite Exhaustive and Detailed.

Build a Project

Starting Electronics – a simple first project.

Here he teaches in simple tongue, The method and steps to towards the first project and that too, with the Sacred SG555 Timer.

Collection of calculators, ready-reckoners

Here is where he dazzles, He has developed very useful Calculators to make your Numbers Game a Piece of Cake.

Besides classical functions and dB conversions, RadioCalc includes a converter of Power to field strength commonly used for EMC/EMS test-set-up. Also impedance can be represented as a function of reflection coefficient (somehow like an electronic Smith-chart). This and many other functions are obtained by clicking into the arrow of the “Conversion off” window.

Radiocalc – Convertisseur Radio Universel

dB calc Radiocalc

Thanks to RadioCalc the different dB charts are obsolete by computing the ratios of Power (W) or Voltages (V) according to dB = 10*log(P2/P1) ou dB = 20*log(V2/V1).

Just for a trial : type 100/10 (or just 10) and push the dB button as the ‘W’ mode is chosen, the result will be 10 dB, then choose the ‘V’ mode by clicking in the V button (in the Quick dB window) push again dB, the result is now 20 dB.

From – Temcom – Consulting for test & measurement and electronics in France

(This was Earlier Radiocalc, i have now updated the link to the new site in France)

Learning AVR Assembler with practical examples, Want to learn how to program AT90S AVR processors in assembler language? This is the page for you!

AVR Assembler Tutorial - Gerhard Schmidt

AVR Assembler Tutorial – Gerhard Schmidt

Erlernen der AVR-Assemblersprache mit praktischen Beispielen. Wollten Sie schon immer Assemblersprache von AT90S AVR-Prozessoren erlernen? Das ist die Seite zum Lernen!

Four simple programming examples with extended comments as first steps of a practical introduction to assembler programming: Sense and requirements, Simple programming examples

Converting a digital value to an analog voltage using a buffered R/2R network, including wave generation like sawtooth, triangle, sinewave forms and a small tone player application.

DG4FAC – Gerhard Schmidt