Using my old Android phone purely for FM radio

Samsung will be the next major phone manufacturer to enable the dormant FM chips in its devices. The FM chips will be switched on in Samsung’s “upcoming smartphone models,” which will allow users to listen to local radio stations.

via Samsung is the latest OEM to unlock FM chips in new phones | Ars Technica

This recent update is interesting to me at least because my current phone is a Samsung. Of course it means my current model won’t have its FM receiver unlocked (and, in fact, I’m not even sure the UK model has FM functionality, enabled or not).

When I first read a few years ago that most phones’ WiFi/Bluetooth chips also enabled FM reception, but that most manufacturers disable it in software, I was baffled. But I’d lived under this cloud of ignorance for many years and never questioned it.

Before my current Samsung, I had one, and then another newer, Motorola Moto G – cheap and cheerful – which both had FM radio apps built in. And great apps, too! Good reception (as always with smartphones, using the earphone cable as an antenna), and the software is simple yet robust. It covers the basics, like auto-scanning, presets, sleep timer, and even RDS display.

But it also has a really nicely-done record function which not only directly makes an MP3 of the station you’re tuned into (rather than, say, recording the speaker via the mic or something hideous), but also automatically inserts the frequency into the filename when it saves.



The Motorola FM radio app makes for a great companion to pirate radio bandscans in a built-up area.

The presets/memory enables me to check for new stations I’ve not picked up yet, or to check on ones I’ve saved previously. Having a list of saved frequencies is great, and saving some as favourites makes it really easy to navigate a sea of potentially anonymous numbers.

The RDS enables me to get relatively quick station IDs with a decent enough signal (waiting for a twenty minute drum’n’bass mix to finish just on the off-chance the DJ actually name-checks the station is a bit beyond my levels of patience). And it turns out that pirate stations seem to love RDS – it’s rare I’ll find a station that doesn’t at least display the station ID. Some even post the show/DJ info, or a contact number/URL. There’s no easy way to export this data (not even copy and paste), but a quick screengrab will do in a pinch.

And, of course, the record function is fantastic for grabbing clear sample clips really easily. It lets me either record for 30-60 seconds to grab a reference clip, or I can even tune in, hit record, and leave it going with the screen off and audio on mute if I need a longer clip to grab a station ID.

It’s a bit of shame the recording function doesn’t have a buffer – quite often I’ll have heard a vital station ID or something else interesting and wasn’t recording. It’d be amazing to have a 5-second buffer for moments like that. Either way, the files are then saved on the device (or SD card, optionally), labelled and dated, and ready to be listened to on the device or exported to a computer/the web at a later date.

Anyway, now that I use my Samsung as my main phone, I held on to the old Motorola – and I’m glad I did. After a factory reset, and stripping off any unnecessary software (Moto phones run virtually stock Android, thankfully), the phone is a pretty decent pocket FM radio.

Running no other apps and living in airplane mode, the phone has a standby time measured in weeks rather than hours. And that’s if I choose to leave it on between sessions, which I do out of convenience, but could make it last month between charges if I needed to.

Of course it’s an overpowered/over-featured FM radio. But it’s one that lets me do some cool stuff, as well as make recordings, take screengrabs of RDS data, and make notes on the fly.

One next step would be to do some field tests – to compare the phone’s sensitivity with that of a ‘good’ FM receiver. Anecdotally, it certainly feels like the phone picks up a decent number of signals, locks onto them well, and performs pretty well. But until I’ve done some side-by-side tests, I can’t be sure. (Ironically, my ‘good’ FM receiver lacks both RDS and any recording function.)

Beyond that, I can also try again with the DVB-T dongle I’ve got for scanning other frequencies. But that necessitates some fiddly dongle/power/adapter compromises, as well as needed a more robust antenna. Simply using the phone as an FM radio with some cheap earphones and built in software is working brilliantly.