Ham-Radio

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.

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

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.

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

delabs

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

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.

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

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)