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Electronics Tutorials – Ian Purdie VK2TIP

Offering free comprehensive basic electronics tutorials in amplifiers, antennas, ham radio, filters, oscillators, power supply, receivers, test equipment, transmitters, radio design and electronics design. Links to data sheets and electronics reference and text books.

Electronics Tutorials – Ian Purdie VK2TIP

Amateur Radio, Amplifiers, Antennas, Basic Electronics, Ham Radio, Oscillators, Test Equipment.

Starting out you need to cover simple electronics which encompasses the topics of ohms law, voltage, current, resistance, capacitance, inductance, reactance, impedance and Q. Further topics in these electronics tutorials are power supply basics as well as digital basics.

Electronics Tutorials - Ian Purdie VK2TIP

What are voltage controlled oscillators

A voltage controlled oscillator or as more commonly known, a vco, is an oscillator where the principal variable or tuning element is a varactor diode.

VK5JST Amateur Radio Ideas with Photos

The new Ham Project Pages are VHF/HF Aerial Analyser, A 600MHz Frequency Counter.  Then there is a an ESR Meter for Electrolytic Capacitors.

VK5JST Amateur Radio Ideas with Photos

With a two tone tester, a dummy load and an oscilloscope, a transmitter can be really put through its paces. Two tone testing consists of applying two clean non-harmonically related sine waves of approximately equal amplitude to the audio input of an SSB transmitter.

Simple Two Tone Oscillator


The sine waves are typically around 600 – 700Hz and 1800 – 2000Hz i.e. about 300Hz from either end of the audio pass band.

A Simple Two Tone Oscillator

This project was published in the September 2004 issue of the Australian magazine “Amateur Radio”.

Other Readworthy Pages

  • Easy PCB’s Made With Kitchen Appliances
  • How to Make a Q Meter
  • Making a High Current 13.8 VOLT Supply For SSB Transceivers
  • VK5MM’s excellent amateur radio homepage
  • Transformer Construction Details
  • Shortform Method of Designing Power Transformers

The photos at VK5JST Homepage are very educative and express the idea better than words. – delabs

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