Should DAB be on portable shortwave radios?

At least since the 1970s, portable world band radios have covered the FM broadcast band (and of course mediumwave). People would purchase a radio to listen to shortwave broadcasts when on holiday, but they could also use it as a normal radio while at home. Back in those days there was no internet and international phone calls were prohibitively expensive. Shortwave was often the only viable way to receive information from your home country.when you travelled abroad. Some countries even ran a service to alert specific persons about an urgent situation at home, like an unexpected death. Radio Netherlands was such a station and my father and I were very keen never to skip this broadcast for a single day.

The market for shortwave receivers has decreased and shortwave listening has shifted from the broadcast bands to the amateur bands. There are far fewer stations broadcasting on shortwave and the ones that remain are mostly either religious propaganda or China Radio International. In the western world. any interesting broadcast could be listened to more conveniently via the internet.

But as any avid shortwave listener knows, you do not listen to shortwave broadcasts just to get the information, but for the thrill of receiving a signal from a great distance, especially if that signal was not supposed to reach you at all. For example if a religious broadcaster beams from Australia to India, but the signal takes the next hop and reaches Europe too.

If you live in an apartment with no real possibility to have an outdoor antenna, portable radios are the way to go. Even a nearby park in your home town gives you better reception than when you are at home.

None of the world band radios currently on the market has DAB+, but I think it should be included for the following reasons:

• If it was a good idea back then to have FM, why shouldn’t we have DAB+ on today’s world band radios? It’s the main broadcast band in many European countries.
• Some EU countries (but not The Netherlands) have laws that require all broadcast receivers to support digital radio. Apparently this is not widely enforced for shortwave radios, but why can’t we just have DAB+ on some of these radios anyway?
• Nearly all DAB+ radios also receive FM, but it is almost always implemented very poorly in terms of usability. One of my Sony DAB+ radios has excellent FM reception, but it mutes for over a second when you tune, even if just one 50 kHz step. This makes it impossible to explore the band by manual tuning. Some other radios refuse to stop on a station that’s too week, but they could hear the station if you do manage to get on that frequency eventually. The least thing we need is a DAB+ radio where the FM band can be manually tuned the same way as on traditional radios. And how much more DX-friendly could we make the DAB-side of things? In terms of manual tuning and useful information to identify a multiplex?
• When I’m actually travelling, I would want to pack one radio and have coverage of both local DAB+and the other bands such as mediumwave, shortwave and FM. Plus SSB on the amateur bands.

There are reasons why DAB+ isn’t included on world band radios:

• DAB+ is only a thing in Europe (and not even in all EU countries) and a few select other countries like Australia. It’s not used in China, where all manufacturers are and not in the USA, where China’s biggest export market is.
• Radios made by Tecsun (the largest manufacturer), have a numeric-only display. A DAB+ radio needs to be able to display station names. Tecsun radios don’t have RDS on FM either, even if they contain a tuner chip that demodulates the RDS bitstream..
• Some radios do have 14-segment displays for station names (like the Sangean ATS-909x), even some DAB+ radios do, but for serious DAB+ support you are practically required to have a matrix display. Matrix displays require a more complex CPU to control them and they cannot stay on while the radio is off. Many portable world band radios display the time when they are off, which is very practical when you use your travel radio as an alarm clock. The CPU needs very little power to maintain a 7-segment display.

There is a whole cottage industry in China that produces longwave, mediumwave, shortwave, FM receivers based on the Si4732 or TEF6686 tuner chips, combined with a colour matrix display and an ESP-32 microcontroller. Some of these have numeric keypads, some of them have airband coverage and some combine the Si4732 (that can do SSB) and the TEF6686 (that has better overall AM and FM reception) in one radio. Some of these designs are open-source. There is a separate open-source design based on the Si4684 that receives DAB+ (even though the chip can do FM, this is not enabled). There are SDRs based on the Raspberry Pi Pico, that can receive 0-30 MHz in all modes with little more than a Raspberry Pi Pico, some analogue multiplexers and frontend filtering.

The chips exists, the designs exists, so why shouldn’t some hobbyist throw an Si4732 and an SI4684 in one box to create some half decent world band radio with DAB+? Or turn the Raspberry Pico Rx into a capable receiver for 0-30 MHz and pair it with the Si4684 for DAB+ and FM?