SWLing Post contributor, Fred Studenberg, recently contacted me about an ingenious car (mobile) shortwave radio he’s designed. Though originally designed for his own personal use, Fred’s now considering initiating a production run of the radio for the commercial market. To do so, however, he needs funding to help pay for parts, and this is where we can help: by voting for his shortwave car radio design in this contest–! Fred writes with details about his radio:
I wanted a high performance shortwave receiver in my car without the clutter of a separate unit under the dash. It had to be easy to tune stations and not require any modifications to my car’s built-in radio and audio system. I looked everywhere, and there was nothing that even came close to meeting my requirements.
Being a retired RF communications engineer, I set about designing a high performance digital radio. It installs remotely in the trunk or hatchback area and broadcasts tuned shortwave audio to your car FM radio. No modifications at all to the car radio or FM system are required. It is powered right off your car’s power plug.
Operation is simple: tune your car FM radio to 88.1 or 88.3 and use a small handheld wireless key fob controller to scan through the 100 preset channels. You have access to full shortwave band coverage in 5 KHz tuning steps with excellent sensitivity and selectivity. There is even a digital noise blanker to eliminate spark plug ignition interference. You can also manually scan to find new stations to add to preset memory, quick tune to WWV for time checks, and even switch the audio bandwidth for voice or music.
If your FM radio has RDS display you can see the tuned shortwave frequency as well as a digital “S” meter. If your car radio does not have RDS, it still works. Just press the scan button on the wireless controller until you hear something interesting or go into manual mode and scan the various shortwave bands listening for something of interest.
This started as a project just for my use, but after I showed it to a few people, I was encouraged to make it commercially available. I’ve entered it in a design contest that will provide $10,000 worth of parts to help launch a production run.
You can see full information on the radio at www.carshortwaveradio.com and there is a link right at the top to take one to the voting site, or go directly to the voting site at Your IoT and look for the car shortwave radio entry.
If readers are interested in seeing this in production, indicate your interest by voting. You have to vote by logging in with your Facebook account, which presumes you have a FB account–if not, they are easy to set up, and you can use a pseudonym and leave out all the personal info they ask [for] at signup.
I voted for Fred’s design earlier today. It does require using your Facebook login to vote, but the contest site can only read the public profile you choose to provide, and–if you allow it–your email address.
If you have a Facebook account, please consider helping Fred out by voting for his shortwave car radio design!
I can appreciate Fred’s motivation, but would not spend over $200 on his device when I can buy a Software Defined Receiver for about $50 which can be connected to the micro USB port on a tablet or mobile phone. Then you can feed the audio to your amplifier using the phone’s headphone jack or the bluetooth interface, instead of retransmiting on the commercial FM band. With a SDR you can also receive the DRM stations (which is the emerging world standard for digital broadcasting on the HF bands.) The improvement in sound quality is amazing, and I would not go to the trouble of installing a mobile receiver which does not support it.
All of this just serves to demonstrate that the market is ripe for manufacturers to start making integrated SDR/DRM chipsets for mobile applications: when inexpensive mobile DRM shortwave receivers become widely available, most HF broadcasters will switch to digital transmission. A GPS unit could also serve as a SDR controller.
Hard core shortwave enthusiasts will tolerate poor sound quality because they like to listen to distant stations. But the general public is only interested in reliable reception of their favorite programs. We have to remember that DXing is a hobby and most people will not buy a receiver for that purpose alone: domestic HF radio services which employ DRM have the greatest potential to reverse the decline in popularity of SWL.
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DRM/SDR REFERENCES
All India Radio broadcasts will be digital by 2017
http://www.drm.org/?p=2774
http://www.automotiveworld.com/analysis/electronics-analysis/91433-drm-initiative-enables-mass-market-in-car-digital-radio/
USA approves DRM for HF broadcasting
https://en.wikipedia.org/wiki/Digital_Radio_Mondiale#International_regulation
http://usdrm.com/
DRM audio samples
http://www.drm.org/?page_id=2396
(switch to analog at 1:02)
https://swling.com/blog/2014/06/happy-summerwinter-solstice-listening-to-new-zealand-and-australia/
SDR hardware
http://www.rtl-sdr.com/roundup-software-defined-radios/
https://en.wikipedia.org/wiki/List_of_software-defined_radios
SDR software
http://www.rtl-sdr.com/big-list-rtl-sdr-supported-software/
http://www.amrad.org/projects/sdr/
http://www.dxzone.com/catalog/Software/DRM
SDR transmission
https://www.drm-sender.de/
http://www.audioblog.iis.fraunhofer.com/xhe-aac/
SDR reviews & forums
http://www.hamradioscience.com/category/sdr-radio/
http://www.rtl-sdr.com/forum/
HARDWARE DESIGN RESOURCES
A software defined radio co-processor capable of decoding all three major digital terrestrial radio standards including DRM, HD Radio and DAB/DAB+/T-DMB. The SAF360x is the first chip to support in-vehicle DRM reception, including two on-board DAB tuners and memory with support for up to three tuner inputs.
http://www.electronics-eetimes.com/en/sdr-chip-supports-multiple-digital-radio-standards-drm-hd-radio-and-dab.html?cmp_id=7&news_id=222919603
http://www.nxp.com/news/press-releases/2014/01/in-car-digital-radio-ready-for-take-off-with-groundbreaking-car-infotainment-solution-from-nxp.html
Digital Radio Processors
http://www.nxp.com/products/automotive/multi_standard_digital_radio/SAF3561HV.html
http://www.nxp.com/products/audio_radio/digital_radio_processors/
Software-Defined Radio Handbook
http://www.electronics-eetimes.com/en/software-defined-radio-handbook.html?cmp_id=34&news_id=222925715
The box would be interesting but I live in Europe…
To convince me to must have this box two features are still missing:
– DRM reception (I know there are very few transmissions in this mode but one can dream)
– DAB+ reception, at least on the VHF band
The 5 kHz steps are no problem for me: 9 kHz for the AM band would be fine, but this band is more or less dead if one only understands German and English.
vy 73,
Alexander
On the 5 KHz steps – I thought international agreement was that shortwave broadcasters operate on 5 KHz steps. Plus, the BST-1 will automatically center on a station that is up to 1.2 Khz off the 5 KHz center frequency. However, the digital tuner actually tunes in 1 KHz steps so it is possible to implement some key fob function that toggles between 1 and 5 KHz steps for tuning. The RDS display will also support that.
As for the market – there are a lot new of shortwave radios being sold to someone to listen at home! If something is worthwhile listening to a home, why not when driving? With the digital noise blanker and the external whip antenna, I think reception quality in the car is the same as what you’d get at home with any decent small portable radio using its built in whip antenna.
Fred, fair points.
Regarding 5 kHz steps, it just struck a chord because it’s one of my biggest issues with my current portable SW radio (Grundig Reporter 2).
I agree about reception, there’s no reason a 39″ whip on a car can’t perform as well as a 39″ whip on a portable radio.
Regarding possible audience, I’d be interested in knowing what actual sales numbers for portable SW radios is and where those sales are occurring. Once I had those numbers, I’d want to match that with car ownership rates do try and figure the likelihood that someone with a car in those countries would want an SW radio in their car…
I realize this is a fun project for you and I’ve described how Blaupunkt would assess the market for this radio, but I really think you need to approach this project from that perspective, understanding that you’ll be lucky to enter the consciousness of a tiny, tiny fraction of the ‘possible’ market (but that may be sufficient for a very successful project).
Were this radio to be able to tune SSB and CW well AND be priced competitively with lower-priced Ham HF radios I believe there would be a secondary niche market for hams that want to listen to established nets on various HF bands. I think the ease of use of the design you describe would be attractive for folks that are reluctant to drop an HF rig, antenna tuner, and an expensive tar heel antenna for a ‘proper’ mobile station.
I enjoy marveling at what I can pick up with my Grundig Reporter 2 portable SW radio with it’s built-in antenna (I think hearing a decent signal from Taiwan & Australia here in NJ is pretty good…), and I support your project.
From the brief description, it’s a clever design and probably warrants a limited production. I don’t and won’t use Facebook, though, to vote. Consider this e-mail my vote…. 😉
The use of FM’s RDS is a nice feature. I’d like to see Fred add DRM capability to it, too, eventually. 🙂
I’m very curious what the market for this. SONY, Philips, Pioneer came out with these before. In the 70s Blaupunkt, Beacker also had models. But even in the 70s it was a flop. You can still find the SONY, Phillips and Pioneer on ebay or from time to time what is called new old stock.
The ones that were sold were mostly exported to Indonesia, Malaysia, Philippines and a couple of Middle East nations.
Even when I tried using a shortwave in each of my cars there was one major issue. Interference from the cars themselves and interference from the surrounding.
Even when I tried using a shortwave in each of my cars there was one major issue. Interference from the cars themselves and interference from the surrounding.
That is an avoidable/correctable problem – many, many hams operate HF mobile.
Yes but thats the super geeks. I doubt that your average SWL is going to start to fiddle with stuff to be able to hear content that is already available from other sources.
A well-built modern car isn’t that bad, as can be found out by simply taking a portable SW radio into your late model car and tuning around the dial as you drive.
If the only accommodations to reduce interference required is a choke on the power and antenna leads, those are very, very trivial efforts and could be handled by the manufacturer, not left for the radio installer.
Yeah, I think the idea is he’d make enough of a production run to meet any niche market that might be interested. If this comes to fruition, it would be cool if he could share sales numbers. I don’t think it would be a huge number, but perhaps enough to justify the effort. Fred claims he’s had good success mitigating interference with his own unit.
I think I’d be more inclined to ‘scratch that itch’ (SWL in car while driving) with either http://remoterig.com [1] or similar remote control of a fixed receiver.
I like the idea/challenge of a SW receiver in the car, but I don’t think I’d really do it.
(I wonder why this fellow didn’t go the kickstarter route and offer finished radios as the incentive… Just curious, it may not be a suitable project for kickstarter, or maybe he’s really on the fence about really committing to doing this at this point…)
[1] this particular site requires a windows tablet, laptop, desktop for remote control.
The RFI problem is curable:
– Have a *good* ground connection at the antenna base. Most active RX antennas have, most CB or ham radio bases have not.
– Add a current yoke on the antenna cable directly at the antenna base.
– Insert a common-mode yoke into the power supply lines.
Remember what I wrote about the computer noise at a RTL-SDR?
vy 73,
Alexander
I’ve got a Sony MEX-BT2750 shortwave car radio that I got for $75 AUD from a local pawn shop because I was after a head unit with Bluetooth capability for my cellphone so I can use it as a hands free & for streaming of mp3 content in my ’92 SV21 Toyota Camry & I’ve had no electrical interference issues with my installation & I use it to receive RNZI & other shortwave broadcasts alongside interstate Australian MW stations.
5 kHz steps!?!?
Yeah, that caught my eye, too. I think 5kHz steps would discourage me if it were a tabletop or portable. For a car radio, though, I would be quite content tuning in broadcasters in coarser steps (especially while driving).