“Spijker” is a dutch word for nail, which you would normally use to hang something on the wall, or to construct wooden stuff. However, (brass) nails can also be used as as solder pad. PA0KLS used this idea to construct a receiver, called the “Spijkerradio” (nail radio). It is a nice project for starters to build their own radio.
The receiver is based on the good old 0V1. This was a very simple receiver with only one tube. PA0KLS redesigned the schema to replace the tube by transistors. He also added a small audio amplifier to allow usage of modern (low impedance) headphones or a small speaker.
All details of the radio were published in a series of articles in the dutch hamradio magazine “Electron”. You can download a collection of these articles here.
Most components come from my junkbox. I only bought a new FET, varicap, connectors and potentiometers. I used a PVC drainpipe for the core. All panels are made of copper clad.
I printed the front on self-adhesive label, then sticked it onto the (drilled) copper clad, and covered it with “Boeklon” (self-adhesive transparent plastic foil, normally used to seal book covers). Finally I cut out the holes and mounted the potentiometers.
I did not add the “fine tune option”, so tuning is a little bit difficult, it is doable however. The radio receives lots of stations, depending on your antenna type and position of course. The result looks very nice, and is a fine example of building your own stuff with simple materials. Although it is meant to be a starters project, I think it’s a bit too much to start with, especially for kids since they would like to have results in just a few hours. I think this project took about 15-20 hours altogether (apart from waiting for the paint to dry).
This project is more about building than using. Yes, it does receive radio stations, but don’t expect a stable or sensitive receiver, it simply isn’t. Still, it is a lot of fun to build it!