QRP and Youth

Part 5

Having built the MW receiver we started with the construction of the multi-purpose operating keys MPK-1. First we made the key itself. For it we used a micro-switch, a leaf spring made of "glasstextite" and wooden knob. The baseboard was made of 10 mm thick plastic plate.

From below we glued the hard rubber along the circumference, so the key will not slide over the table.

As with making shoes, we grind on the grinding machine the circumference of the baseboard along with the glued rubber.

The important detail of the micro-switch is placed on the baseboard. It is a quite small plate which limits the jump of the micro-switch. The keying is then more precise.

We produced four keys altogether. The prototype is on the left.

The wiring of the MPK-1 key was checked on the testing board.

The prototype of the MPK-1 is ready.

Honza Kříž has just finished his version of the MPK-1. It differs through its placement (turning) of the PCB board and with the location of the 2.5 mm jack connector for the transmitter cable.

The three keys are ready. From the left: the prototype, the products of Jenda Kříž and Jenda Kořínek. The fourth key will be Michal's but will be delayed because of his injury.

The full description of the MPK-1 can be found HERE