Image via the KTWR Blog
Many thanks to SWLing Post contributor, Dan Van Hoy, who writes:
[Regarding the reception of DRM via smart phone,] I happened to find this KTWR Guam post about decoding DRM30 with a smart phone, app, and an RTL-SDR:
Convert Smart Phone to DRM 30 HF receiver!
We are pleased to report successful use of an SDR Dongle used to directly receive and Decode DRM 30 over HF today.
The SDR Dongle is an RTLSDR v3 type connected to an android smartphone using an OTG cable (phone or tablet must be OTG capable).
The Software used:
1. Android driver (free)
2. DRM+SDR Android App ($4.99)The Frequency of the HF broadcast is directly assigned within the DRM+ SDR app with two settings
1. Frequency in Hertz
2. RF Gain (0-512)Demonstration video showing Clean DRM decode of AAC Audio and Journaline data along with live metadata. (our signal was very strong, so only a short wire used for Antenna, DX’rs will need an appropriate Antenna)
Now anyone with a smartphone and a $20 SDR can receive DRM 30 HF broadcasts…
You should have a test station always on day and night in SW (or in MW), which always sends the same announcement in various languages (English, Italian, German, Romanian, Chinese, French …) in DRM30, so that we can test our SDR RTL2832u receivers, IF downconverter, and be able to test them try if they work well.
Sounds great but…
Phone battery won’t last long with a dongle attached to it (requires power).
Phone will be doing a lot of processing / cpu cycles = lots of power being used.
On air content, come on be honest, most programmes are as dull as ditchwater
and impart barely anything of value to the listener.
It’s a bit like analog vs digi voice repeaters on ham radio.
Except you spend more time trying to get the darn radio to work / connect / programmed / updated
than the time you ever spend actually having a QSO.
Might just as well cut the wasted time out and use an old IC2E and an analog repeater in the first place.
It’s also why DAB radio on a cellphone is a bad idea, battery life !
Best to stick to plain old FM broadcast = low current receivers.
OK, so we’ve got an app for Android phones. Is there possibly going to be one for iPhone’s ?
Not many people are aware of this. But when the iPhone was conceived at the end of 2004. The original design team, which is different now. Actually looked at DRM as it only was the matter of adding the decoding chip, but passed as back then as now there is no market. Apple wasn’t the only one. Samsung also considered it, but didn’t see any value to it. I only know then from an interview I did with Danny Coster who was part of the original design team who left Apple in 2016.
They even in 2006 had a presentation team from the DRM Consortium give them a presentation. But after they researched themselves an could not find a consumer product from any major manufacture or even content. The idea was axed.