My radio died a few weeks ago, so after taking it back for a refund, I decided to jump into the brave new world of DAB+ digital radio. My approach to this was to buy the absolute cheapest DAB+ receiver I could find here in Melbourne, which turned out to be the AKAI KDR-66RU for $38 at Big W.
Upon plugging it in and turning it on, it automatically started up in DAB+ mode and searched for stations. The clock set itself automatically from the DAB+ signal, and after flickering back and forth a few times it ended up in the correct time zone. (There is no option to set the clock manually.)
There’s one 5cm built-in speaker. The sound quality is mediocre on FM and worse on DAB+. Some of this may be a consequence of low bitrate transmissions, but I suspect the hardware is also a very significant factor.
The thing that annoys me most about this radio is the slow and tedious process of tuning it and selecting stations. Pressing “prev” and “next” moves through the list of all stations, but that’s a long list so I set my favourite stations as presets. And to switch to a preset station, you need to press “preset”, scroll through the presets with “prev” and “next”, then press “enter”.
Three button presses (at least), plus needing to look at the station name on the screen, isn’t a convenient experience for someone like me who likes to switch between channels a lot. Particularly combined with the fact that it sometimes takes over 5 seconds for the new station to actually start playing.
I know it’s possible for DAB+ to tune faster than this, but having not tried any other DAB+ receivers I don’t know how common it is.
Anyway… while I was testing the sound quality, I plugged external speakers into the headphone socket to see if they improved it much. When I unplugged them, I accidentally unplugged the power too, and after reconnecting it the receiver stopped working. Whether I was on DAB+ or FM, and whether I was using the internal speaker or not, it just produced a faint buzz rather than the received audio. Turning it off and on didn’t help, and neither did selecting “reset” in the menu, but it started working again after I disconnected and reconnected power for a second time.
At this point I’d decided I didn’t like this radio very much. So… let’s see what’s inside it!
The main board includes voltage regulators, a single-chip amplifier, and the keypad buttons.
Looking at the corner of the main board, we see this model number DAB6R, which leads us to where this radio actually comes from. (Update: I had a link to the manufacturer here but the page no longer exists.) Apparently it’s produced by Anchor Far East Co. in China.
This module, the Quantek Q8R+, contains all the “smart” stuff… it processes the keypad input, drives the LCD display, and includes a tuner and decoder for DAB+ and FM radio.
You can even get a datasheet with pinouts and specifications for the module! Unfortunately there’s no firmware available to the public to make it do anything cool, and I have no convenient way to connect other hardware to the module right now, so I put my radio back together rather than trying to build something awesome with it.
After several more resets and power-cycles, it started working again. And there’s a digital-only station here dedicated to the ’80s, so I suppose DAB+ isn’t so bad really. 🙂