Makita DAB Radio Modifications

[Dimwit]

I wanted a Makita DAB radio but found it didn't come with bluetooth, this only comes with the FM version. So I bought the DMR104W model and I first used a bluetooth dongle plugged into the aux socket but found I had to keep connecting to it and charging it. After looking on the internet I found a few people had modified these radios to include a 12V radio decoder audio module complete with bluetooth, USB and SD card reader and a remote control these modules are designed to be fitted into a car. I also saw a few other interesting modifications which gave me some ideas.

The original radio

919ba2b964d10e911a7b9066d4a5e5d6.jpg (167.56 KiB) Viewed 10344 times

So I bought some parts off ebay including a Bluetooth radio module, a 2 port USB charger socket, a cigarette lighter socket, illuminated rocker switches and fuse holders.
My plan was to fit the radio module to give me Bluetooth, USB sockets for charging phones etc and the cigarette lighter socket so I could plug in accessories like a LED work light. Each of these to be switched on/off by individual switches and have fuse protection.

Radio module

p.jpg (8.05 KiB) Viewed 10344 times

USB socket

resized 1.jpg (136.12 KiB) Viewed 10344 times

Next came the scariest part drilling and cutting holes in the radio case. I decided to mount the cigarette lighter and the USB sockets on top as they have dust covers and would have protection when working on dusty sites. The radio module, switches and fuses holder were fitted on the right hand side to keep them all neatly together also the left hand side has a large metal plate on the inside used as a ground plane for the aerial. I managed to fit the radio module where the DAB logo was and it fits in just right in between the moulded lines. The fuse holders fitted perfectly in the space in front of the handle with the switches in a row below them. The output of the radio I connected to the AUX 2 input in the radio's battery compartment using a 3.5mm plug giving me the option of still using the input for something else if I want.

resized 2.jpg (164.71 KiB) Viewed 10344 times

resized 3.jpg (151.7 KiB) Viewed 10344 times

resized 4.jpg (174.71 KiB) Viewed 10344 times

The radio takes different Makita batteries and can also run off a mains adapter. I wanted all my mods to operate off all these as well, but was concerned about extra loading being put on the built in regulator pcb and possibly damaging the regulators. So built my own regulator board with two regulators one for the cigarette lighter socket and the other for the radio module and the USB sockets I also fitted diodes to block voltages being fed back to the output of the original regulators just in case they didn't like it. I mounted the regulators on a small piece of aluminium to act as a heat sink and it also gave my an ideal way to fix it at the rear of the case above the original regulator board.

resized 5.jpg (165.72 KiB) Viewed 10344 times

Once everything was fitted it was just a case of wiring it all in. Like I said all the different battery connectors and the mains adaptor input connect to my regulator board, with one regulator supplying the cigarette lighter socket via a fuse and the other regulator supplying the USB sockets and the radio module via the second fuse and each one can be switch on/off by it's own switch.
So far it has worked well and once I connected my phone via Bluetooth it remembers the pairing so no need to keep reconnecting.

resized 6.jpg (215.6 KiB) Viewed 10344 times

resized 7.jpg (129.66 KiB) Viewed 10344 times

resized 8.jpg (211.7 KiB) Viewed 10344 times

resized 9.jpg (183.08 KiB) Viewed 10344 times

[boxedin]

Very smart modification looks good

[Dimwit]

Thanks boxedin for the comment. It turned out even better than I thought it would.

[Konstantinos_K]

Superb work mate. It's integrated really good.

[getthewheelsinline]

Looks tidy! Got the makita DMR109 & would like a USB charger point only. Where did you take the 12v feed from to supply your new board? I plan to just test directly to the 12v output.

Thanks in advance.

[kellys_eye]

Are those regulators insulated from the heatsink? Many (but not all) have one of the pins connected to the heatsink tab (commonly the output) which leaves the heatsink 'live' (ok, only 12V but it's still a potential shorting hazard) so the heatsink needs to be kept away from other wiring/earth points.

[Dimwit]

"getthewheelsinline" Thanks for the comment
I took a feed from each of the three battery connectors and one from the DC adaptor intput to supply the voltage regulators on the new board. I also fitted a diode on each of these feeds to stop voltages being fed back to the orginal regulators.
I did consider picking up on the supply to the front mounted pcb after the orginal regulators but was concerned about extra load on them and the orginal wiring.

[Dimwit]

"kellys_eye" The regulators are not insulated from the heat sink just a small amount of heat sink compound under them. The tabs on both are connected to the ground pin. I know the heatsink is now connected to the ground of the new circuit but as the heatsink is secured to radio case and there is nothing live loose floating around inside the radio it has not been a problem.