RASON Projects Page

Designing Bipolar Transistor Audio PreAmps, Designing JFET Transistor Audio PreAmps, Designing Op Amp IC Audio PreAmps, Switching Regulator Basics, Using Transistors As Switches.

RASON Projects Page – Amateur Radio

  • 10 Amp, 13.8 Volt Power Supply
  • 12 Volt Gel Cell Charger
  • Thermal Fan Controller
  • Transistor Audio Amplifiers
  • 12 Volt Gel Cell Charger
  • Switching Regulator Basics


A Potpourri of Audio Amplifiers  By N1HFX

“I intentionally avoided the use of IC amplifiers to provide a real learning experience for audio amplifier design. Although many IC amplifiers provide excellent performance at low cost, we need to learn the basics first. I will address IC audio amplifiers in a future article.”

The Radio Amateur Society of Norwich
P.O. Box 329 – Norwich, Connecticut 06360

NE612 – Balanced mixer with Local Oscillator

I am designing a circuit that implements an AM radio circuit that ultilises the IC Double mixer and Oscillator NE612. I was just wondering whether there is any standard symbol for this kind of IC.

mail from CM

There is no standard symbol for NE612, just a square box. You have to make a custom part in the CAD software or see if someone has done that. check these links on info of NE612 circuit and symbol….

GM47: Simple 30m Band QRP CW-Transceive

The Rx mixer is followed by a IF stage featuring an NE592. The mixer’s balanced output is directly connected to the amplifier’s differential input, minimizing component count at this point.

Simple 30m Band QRP CW-Transceiver

Direct Conversion Receiver using NE612 for HF Bands

The NE612 is an integrated circuit which contains a balanced mixer with its own on-board local oscillator and voltage regulator. The mixer can provide up to 18dB of gain at 45 Mhz, and the local oscillator will operate up to 200 Mhz.

HF Transceiver using NE612

I would be working on the Transverter first, as with this, I could try out the 9Mhz SSB Module that I already have. I would be building the Transverter for the 14 Mhz band depending on the values from my DC Receiver project using the NE612 IC


N5ESE – Gizmos for QRP Ham Radio

“One day I noticed a project, obviously homebrew, mounted on a piece of plywood, and nearly covering the worktable. When I asked him what it was, he glowed as bright as the half-dozen tubes that lit up when he turned it on. Twenty seconds or so later, out spews from the speaker the cracklings and whistles of 40 Meter CW. I was amazed, and at that moment the homebrew bug bit me hard. I was determined to build something myself, and get my ham ticket.”

N5ESE – Gizmos for QRP Ham Radio

N5ESE - Gizmos for QRP Ham Radio

N5ESE’s GIZMOs For the QRP Homebrewer and Ham Operator

“Everybody loves a “gizmo”. Hams have a weakness for them. Gizmos can be expensive for full-power amateur radio equipment, but homebrewing QRP gizmos is “cheap and easy”. Most of the projects here cost less than $20 (or nothing, if you have a modest junk box), and take only a few hours to build). Most are even suitable for the novice builder. And all have real practical value, especially for homebrewers and QRP operators. “

Amateurfunkbasteln – Amateur Radio Crafts and Electronics

Amateur radio is a technical hobby. The attraction? To cover long distances with a low power radio to talk with other people, learn about their countries and cultures.

Amateurfunkbasteln – Amateur Radio Crafts and Electronics

But amateur radio also means tinker devices themselves, solder, apply electronics and learn something. In this sense, it can be a preparation for a technical career or even an engineering degree.

Use Google Translate, the pages are in German.

A Data Logger that records Slowly varying parameters, such as the temperature or decreasing the voltage of a battery. This copy records up to four measurements on parallel and saves it on a EEPROM.

Four Channel Data Logger - Amateurfunkbasteln

Four Channel Data Logger

It measures self-sufficient – without a PC – analog voltages (0-5V), it digitizes and stores the numerical value obtained in a separate memory. Later, after the measuring and recording phase, passes the data logger its information to the PC.

PY2WM JK De Marco Projects

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

RPC Electronics – Amateur Radio Supplies

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

Homo sapiens to Homo Ludens

A long, long time ago a bright ape figured out that by climbing down from the trees he could more easily master his life, and that of others……Homo sapiens wanted something else, and better. He started to play. Homo ludens was born!

Homo sapiens to Homo Ludens

  • Homo ludens radiactivus – amateur radio
  • Homo ludens radiohistoricus my antique radio collection
  • Homo ludens electronicus – electronic projects
  • Homo ludens aeromodellisticus – model airplanes

Transformers and coils: This is not a building project, but a short and concise lesson in how to design electromagnetic parts. It’s much simpler than what you may expect!

Thermal design: A short course in keeping electronic parts adequately cool.

From Hobby Hound – DIY Electronics

A 40 meter SSB QRP transceiver

“This transceiver was conceived as a power-efficient, small, lighweight unit to be carried in the backpack, along with antenna and battery, for use during trekking and mountaineering trips. It had to be reasonably rugged and reliable, and perform well. Furthermore, I wanted it to solve all the problems the old DSB transceivers had, such as frequency instability, distorted modulation, lack of sensitivity and selectivity, and others.”