Beercan Receiver

The Beercan receiver

Joachim Köppen Kiel 2018

Since it is important that we touch the receiver ground with our hands, as to provide an electrical counterpoise to the antenna, the best thing would be to place the receiver into a metal container.

Why bother about a special metal box? The aluminum can from beer or soft drinks can be used to house the receiver and the 9 V battery. Its round shape fits nicely in the hand.

First, one removes the top lid of the can with a suitable pair of scissors. Then cut or drill a hole in its bottom to accept an insulated terminal for the antenna.

Prepare a round piece of circuit board to fit the opening at the top. This piece will hold the volume control potientiometer, the power switch and the socket for the ear phones. I soldered three M3 nuts to the board, so that three screws can fit through three holes in the can's rim and hold the board to close the can's opening. All these operations can a bit tricky to do it nicely.

The receiver is built on a piece of circuit board or Veroboard, which is held to the round board by a loop of thick copper wire.

Here is a closeup view of the input section:

Here is a pdf about this.

Another very convenient metal container is obtained from small round boxes for tea or candies: They are of suitable size, but they also come already with a plastic cover which makes life much easier.

Because there is enough space, the circuit is distributed on three small printed circuit boards:

On the left is the audio amplifier, at right the input section, and in the middle there is an additional active low pass filter (for 10 kHz):

A look inside the candy tin shows the three boards. The remaining empty space will be filled by a 9 V battery with some bubble wrap around it.

A view of the exterior shows the antenna terminal. The bottom of the candy tin is reinforced by a (decorative) piece from an old empty printed circuit board. This helps to hold the long telescopic whip antenna very steady, and prevents flexing of the thin metal sheet that forms the tin's bottom.

last update: Apr 2018 J.Köppen