Welcome to the radiospurs Web site. Here you can dabble in random Broadcast related engineering topics.
So you want to design and possibly make a stereo encoder for FM broadcast usage. Modern day designs are totally digital, less the I/O parts so that is what will be described here. A DSP (digital signal processor) based design with the option to incorporate a RDS generator
RDS generators come in many forms, ranging from simple hash jobs based upon a PIC to high end DSP (digital signal processor) based generator. Here a simple design based upon a micro-processor is presented. This is a modulator less design based upon a pre-synthesised waveform presented through a DAC (Digital to Analogue convertor)
Filters come in many forms but are either passive or active, analogue or digital. The design varies considerable with the frequency band of use. A stepped waveguide is of no use below UHF (it would be enormous) like wise an active design using op-amps is considerable more difficult to make at microwaves than audio frequencies.
Software comes in many forms. We have already seen examples of micro-controller C code, DSP specific assembler and a C# based windows form application for RDS encoder control. Now other software will be presented: a SNMP client and server, a SNTP module, C# controls
Hardware also comes in many forms. To construct a transmitter is, basically, simple an oscillator, modulator, source of modulation, radiating element. Well we shall look at some of these (The ones I have at some stage designed, developed and in some cases (like the RDS generator) innovated).
Extra hardware will come into play when a complete transmitter system is to be implemented, STL microwave links, combiners etc.. Here are some tools to help with that.
Sometimes a client calls for a project design but then decides not to go ahead, cancels or just goes quiet. Here some of those expired projects are presented. Incomplete in the first instance but available in detail for registered users.