Super small spy transceiver for 80 meters.

A complete radio station hidden in 3 matchboxes.
Antenna hidden in 3 fishing lines.

This is the complete radio station.
Antennae are the three fishing lines.
The matchbox contains power, equipment box and radio station.

On the left we see the power. A 9 volt battery with power cable.
In the middle we see the equipment box. It contains a headset and a morse key.
On the right we see the radio station.

Here you see the equipment box.
It contains a super small morse key and a small earpiece.

And this is the power.
The radio station is powered by a 9 volt battery.
A power cable with 1/10" pins.

This is a complete shortwave radio station.
It consists of an xtall oscillator at 3592 kHz,
receiver and a 0.3 Watt transmitter.
The modulation is CW.

This photo was taken during my first QSO.
120 km to a station in Oslo.
Here we see the Morse key, the earphone and the power.
The wire on the left is for the earphone,
but also has a connection to an audio recorder for my youtube video.

This is the electrical schematic I used during the design and construction process.
The oscillator is on the left. The receiver is at the bottom right.
The transmitter and antenna tuner are at the top right.

!!! This is the drawing from the video. There I had forgotten R1 and R2 in the oscillator. !!!

Mixer is mini circuits ade-1ask or ade-2ask.
Other mixers that go down in this frequency range work fine.


Here I have started the construction of the receiver.
It is placed on a small 1mm circuit board.
The main parts are an NE5532 opamp and a mixer ADE-2ASK.

Here we see the finished receiver.
On the left are three pins.
This is the headset output.
The blue component is the volume control.

To reduce the size, I have used a mixture of normal components and SMD components.


The oscillator also consists of both regular components and SMD components.


This is a 1mm PCB that fits in a matchbox.
On this plate I will mount the receiver and the oscillator.
Directly on the board, I will mount the transmitter and antenna tuner.
Pins on the right are the antenna output.
Pins on the long side are power input and key input.

Here I have started with the installation of the transmitter transistor and the antenna tuner.

The oscillator is also mounted here.

Here the receiver is mounted.

And here the Rx/Tx relay and the transmitter's transformer are mounted.

Now the whole radio is finished. It consists of a receiver with uV sensitivity and a transmitter of 0.3 Watt.


This is the antenna that was used on the Finnish radio KYYNEL in the Finnish Winter War.
It is a fantastically efficient NVIS antenna. It is easy to set up out in the field.
The antenna is balanced and connects directly to the radio.
Therefore, the radio also has a balanced antenna connection.