WhisverseKits, Learn Morse Code, a Telegraph Machine, Electric Circuit Experiment, Kit(No Battery)

I bought three of these for use by our Scout troop. Delivery was from China and took about 10 days. They were quite easy to assemble even with the enclosed small screwdriver. The instructions are in Chinese but I found the pictures to be clear. The fixing screws are quite small and easily lost, so a pot was useful to store them during assembly. The use of press connectors for joining the wires and components was effective and well thought through. One tip if doing this with a group of children : have a soldering iron ready in case a lead breaks at the board (this did not happen in our case). Once assembled and powered, one button activates the red LED whilst the other the green one. The buzzer sounds with one of the LEDs, which one depends which way round it was connected. If the buzzer becomes annoying it can simply be removed leaving the LEDs. I do not know the maximum range, however we used them to send Morse code in the Scout hut over a distance of about 10 m without signals dropping out. One issue is that a single transmitter activates all the receivers in its vicinity. However with care it is possible to pair them by gently adjusting the tuning coils. I did this before the kids assembled them on the wooden panels. In the end, they worked surprisingly well and at the price represent extremely good value for money.