Intro: Velleman MK118 Radio Kit Made Portable!
My grand kids are young and don't have their own radio so I wanted to build this kit with them so that they could understand how a radio works and enjoy the feeling of accomplishment in making something. I would tell them what part I wanted (resistor, capacitor, diode, etc) and they would have to find it and then properly place it on the board (I did the soldering).
Below is a brief pictorial of the modifications made to the circuitry and the project box used to house the circuit.
I took the basic idea of how to house the radio from Powerman666 (https://www.instructables.com/id/FM-Radio-Velleman-Mini-Kit-118RS-Modified/ ) and others and improved on the design to allow the radio to be both plugged in or portable.
In the photo above everything is soldered to the circuit board where it is suppose to go, except the speaker, power adapter and switch.
In the photo above the speaker is attached to the project box lid with longer screws than those that came with the kit. Also, notice the speaker cloth to protect the speaker. The project box was bought at Radio Shack.
Here is the modification I made to the circuit to allow the radio to run from both battery power or "wall wart". See my drawing below. (DANGER...only attempt this modification if you are totally familiar working with electricity, as the use of an incorrect component or connection may result in fire or injury.)
In the picture above I show the cut out for the power adapter. I used a drill bit to create the hole and then my small flat and curved files to shape the sides and bottom. I used my Multi tool with a sheetrock blade to cut the battery door. In the picture below, I've attached the circuit board to the lid. It lays directly on the speaker magnet. I made sure that nothing on the board touches the speaker housing.
In the picture above, I've soldered the push button switch to the circuit board and soldered the antenna wire from the circuit board to the external telescoping antenna. Next I installed the power adapter with the modified circuit and then fabricated a battery partition to fit snuggly into the slots inside the project box and then glued it in place.
With the circuit board attached to the project lid, the volume and tuner knobs from the circuit board stuck through the openings in the lid just enough for me to epoxy these wooden knobs I made. Then I attached an old transistor radio tuning dial so that the dial matched with the radio frequency. See below.
The picture above is not very good, but it shows the battery door with latch and the power adapter.
Below, the door is opened showing the 8 pack battery holder. I decided to attach a cord to the holder and made it shorter than the wire leads from the pack to the circuit board so that when my grandchildren take the battery pack out, the cord will prevent them from pulling the wires out of the pack or board.
They love the radio and take it with them everywhere. I also took pictures of them helping me make it so that they could prove to their friends that they actually helped build it.