Using SMD – part 1

Why do I like using SMD? Let me explain, I began making radios using valves, it was all there was at the time. When I started work in the industry the first training courses were on valves and how they worked. Then the transistor came, then integrated circuits followed by surface mount devices, SMD. I guess I have followed the technology.

It is easy to be overwhelmed by progress and stick with what you know but there are many advantages to using SMD:

  • individual components, resistors and capacitors, are very cheap
  • many older devices are no longer available as wire ended e.g. the SA612
  • PCBs are smaller due to high packing density
  • high frequency boards are easier and cheaper
SI5351 board

An SMD VFO module

Above is an SI5351 board (ready made apart from soldering the SMA connectors) it is just 30mm wide and can used with an Arduino to make VFO with 3 programmable sine wave outputs. Current cost is less than £5 on ebay plus the Arduino.

You might need some new tools like a magnifier, fine tipped soldering iron and good quality tweezers. There are more including heated tweezers and a hot air gun for component removal but they can wait for a while.

So, my advice is do not be put off and have a go. Find a simple kit to practice with and then progress to more complex circuits. It helps if you know something about how SMD components are sized. Srat with the larger sizes and work down.

1206 and 0805 are popular SMD sizes

This is another good one to print out.

Over the coming month I will add to this series of posts and share some of the projects I am working on which include: a remote tuner, vector network analyser (VNA), wide range VFO/signal generator, a switched attenuator.