QRP and Youth

Part 4

We are inventing a prototype for a direct-amplifying receiver. On the test board is a detector similar to an amplifier used in a television. Everything is powered by our adjustable network source.

The head of the lab tested four types of connections, the last one having a bias voltage for the detector diode. When Michael heard how sensitive the receiver was he decided to build it.

The boys started with the most difficult work – winding the coil. There were 70 turns with a tap on the plastic wiring tube.

Small boxes we make from the parts of double-sided cuprextite.

The boys, working at three work stations, finish the assembly of their receivers.

Each receiver looks a little different, according to the imagination of the builder. The boys decided to miniaturize the construction and therefore placed the coils laying down. This allows the front panel to be lower than the prototype. The first one on the left is the prototype, the next one is a receiver by Jan Kriz (age12), the next one is by Jan Korinek (12) and the last one by Michael Riha (13).

The complete description of the receiver is HERE.