EDITORIAL
Issue 2

By now you will have completed the first section in each of our two main courses. This will bring everyone together so we can present some of the more complex aspects of electronics in the near future. 
Even though the majority of modern designs are digital and contain LSI chips (Large Scale Integration), there is still a need for discrete circuitry around some of these chips - mainly in the "front-end."  The requirement is gradually decreasing but there is still a need to connect some to external devices. And this is where our two courses come in. Many of the specialised chips now cater for a variety of inputs but in the area of microcontrollers, the need for interfacing still exists. 
And that's why the Basic Electronics Course is covering transistor stages. These are simple stages capable of connecting every-day devices to digital circuits. Items such as microphones, inductive sensors (magnetic), thermal and liquid sensors are classified as analogue devices and have a small output. This output must be increased so it can be detected by the input of a microcontroller. 
Some microcontrollers have an analogue input to cater for such devices but the two types we are covering in the course do not have an analogue-to-digital converter feature. 
Some of the other PIC chips have internal A-to-D capabilities and are re-programmable, but for now we will be concentrating on the PIC16F84 model. For more help on selecting a microcontroller you can email a very knowledgeable and helpful subscriber: R. Jones.
After two more sections of the course you will see how these circuits interface (connect) microprocessor chips to the outside world.  This will bring our PIC Programming Course and Basic Electronics Course together. 
In the meantime there are more basics to cover and this issue continues with the courses. 

TO COME .  .  .
In the next issue we introduce two extra areas .  .  . FM Transmission and Model Railway projects. 
These two areas have proven very popular in our past magazines and books and cater for some of our most  dedicated enthusiasts. 
FM transmission is commonly called FM BUGGING and although these projects are extremely popular, they are frowned upon by the authorities in some countries and totally disallowed in others. This is pity as they form a very valuable learning tool for both audio and RF designs. 
The only way around this is to keep the antenna very short. 
If the antenna is extended to its full 180cm (6ft) the range of our devices is greater than 400 metres (400 yards) but at 10cm (6in) the range can be reduced to less than 10 metres (30ft)  and the signal will not penetrate the surroundings. 
Most of the quality of our devices lies in the incredible range produced by the circuits and this is circumvented if the antenna is shortened to almost nothing. 
However, the quality and efficiency of the circuit can be appreciated by building the devices and you will be able to experiment with the designs to see how they work. 
The audio quality is superb and they can be used as FM links from a microphone to a recording device such as a camera or VCR. They can be used in security areas to record  faint conversations and although this is another area of contention, we have to accept the fact that security needs to be stepped up to meet the current climate. 
Our devices offer only the basics in FM transmission however the result is absolutely amazing with just a handful of components.  
We have two FM transmitter articles ready for the next issues and they offer a learning experience like never before. You learn about getting the highest "Q-factor" for the oscillator and this involves a correctly designed coil/capacitor combination, correct layout and a matching antenna. 
This is the information you need when designing larger outputs to achieve the maximum range. The maximum range I have heard about is 360 miles with a 360uW transmitter (for a land-based unit). This is equivalent to 1 million miles per watt and some of the transmitters from "Voyager" spacecraft will be achieving better distances than this.   
This is some of the phenomenal enjoyment you can achieve with our simple designs.  

Model Railroad projects are always in demand and we have a range of over 20 projects for the serious modeller.  In the next issues we will be presenting a Capacitor Discharge Unit and Throttle. These are the first two projects you will need for any layout. 
Modelling (car, boat, train and plane) has come a long way with the assistance of electronics. It has made miniature models perform feats of realism that leave me in awe.  When I get down to "eye level" and watch some of the layouts, I wish I had more hours in the day to add to my range of hobbies. 
One thing we have done to add to the realism of layouts is the inclusion of electroluminescent materials. Especially effective is electroluminescent "string" or "rope" or "wire." This is very fine 2.3mm (3/8") "spaghetti" in a range of 10 colours. It can be used to produce miniature fluorescent lights or advertising signs. In the next issues we will have a kit to drive this material as well as flat panels. 

In all we have a lot of material ready for "uploading" and we will keep you posted via e-mail as soon as each issue is available for viewing. 

For now,
All the best, 

Colin Mitchell
Editor - TALKING ELECTRONICS Interactive