Hello again fellow fixers and readers! Since the last weekend, the weather has started to warm up, so it was great to be able to enjoy some warm, sunny weather (while staying safe of course!)
Anyway, last time, Gareth found a couple of radios in our spares room, and of the two radios, we opted to work on the Morphy Richards 27024, since it is the more compact of the two, and that it should be easier to repurpose the radio’s buttons for controlling media playback and other functionality.
So now, it was time to get an inside look of the radio, which can be accessed by removing the six screws (one of which was missing when the radio was salvaged from the spares room) with a Philips screwdriver, and prising open the rear plastic casing with a spudger.
And here’s the internals of the radio! There are a few proprietary circuit boards and other parts that are held in place with screws, so thankfully we didn’t need to worry about any glued down parts that can be a pain to remove.
The antenna for receiving AM radio broadcasts was the first to go; it is a ferrite tube with copper wires wrapped around each side, one for medium wave and the other for long wave. The antenna is securely held in place by four white plastic pieces that are secured to the inside of the back cover with screws, and the wires are soldered to a small circuit board with wires that are joined together to form a cable that is plugged into the mainboard.
The circuit board for the audio jacks, the USB port and the power socket is still mounted on the inside rear casing; we left it in place for the time being, since we may be able to reuse the board for the functionality it provides our build. However, we may need the space it takes up to improvise I/O ports for desired components as needed.
The telescopic antenna was removed next; it was held in place by a plastic piece, a screw affixed to the front casing and a metal bracket with two screws holding it in position. The screws holding the metal brackets in place were removed first, then the once the single screw holding the telescopic antenna was removed, the antenna was free to be pulled out from the top of the radio. We opted to retain the metal brackets, because they provided some rigidity to the case and help the radio resist being moved around accidentally by unplugging peripherals.
The mainboard was the next to go; we decided that it wasn’t worth keeping for the build, since it incorporated a proprietary design that would likely hinder attempts at repurposing the board for our project. Removing the mainboard was a little tricker; it was a case of removing five screws holding it in place, then clipping the wires for the speakers and the circular boards for the control knobs, unplugging the connectors attached to the circuit board for the USB port, audio jacks and power socket, and prising it out with a blue plastic spudger.
Finally, the circuit board incorporating the switches for the front controls and the front headphone jack, was taken out by removing its screws, and then gently prising it out with the blue spudger. The original monochrome display was soldered to the board, and was held in place with a plastic frame that clips to the board itself. We are considering replacing it with a colour display, ideally one that can be installed as a drop-in replacement of sorts while retaining the plastic frame. However, we chose to eschew touchscreen functionality, as I noticed that the front casing had a thick, clear plastic window for the display, and that this plastic window would quite likely make using the touchscreen impractical.
After we gave the circuit board a quick test with the voltmeter, and found it to be a working board, we opted to keep it, as it had all the necessary components that we will need to repurpose the front controls for operating the build in practice. Otherwise, we would have had to source new switches and other components that would fit into the front casing, which can make the project more complicated. Also, retaining the circuit board along with the speakers helps to reduce e-waste by making use of usable parts that would otherwise be discarded along with the faulty or dead components.
So now, we had to decide upon how we will put our build together with the parts that we want to use. There are two possible approaches that we thought about:
- Bundling together microcontrollers that have the desired features. This allows for very quick boot-up times, since this system would only need to start up the firmwares for the microcontrollers, meaning that it can be used almost immediately. Cable management should be fairly straight-forward, since we can make use of the vacant screw holes to tidy up the inside of the radio.
- Using a single board computer with add-in boards for the desired features. This can offer more flexibility, as we can more easily adapt or upgrade our build by interchanging boards as use cases change and/or evolve. For example, if we decided that we want to listen to music from our media collections, then we could install an SSD, either onto a compatible board that attaches to a Raspberry Pi 4 (with a USB bridge connecting the two boards), or onto a custom mount with a USB to SATA cable connecting it to the SBC.
So what kind of radio are we going to build? Will we aim for a radio that receives DAB+/DAB/FM broadcasts? Will it be built for playing internet radio stations, podcasts and music from streaming services? Or perhaps make it into a digital jukebox that plays more songs from media collections than we know what to do with? We’ll reveal what our build is going to be, and how we’ll build up our radio in the next part of this project series! So until next time, stay safe, keep calm and just keep on fixing!