Portable operation of Newstar DR111 DRM receiver

Saturday, August 23, 2014
NewStar DR111 is one of the few commercially available consumer DRM radios. In my experience, the radio works quite well with an external antenna (such as the Wellbrook ALA1530 magnetic loop).  However, one of the main drawbacks of this unit is that it doesn't work off batteries, making portable operation cumbersome. The built-in whip antenna is long and has demonstrated fair performance in the past, but indoor reception with it is typically hindered by local radio frequency interference (RFI).

Radio enthusiasts have engineered some ingenious workarounds for this problem. For example, Alokesh Gupta used a DC-AC inverter to power the receiver's wall-wart 5V DC adapter from a 12V car battery, while Tudor Vedeanu improvised a portable AA battery pack that connects to the radio via a DC plug. Both methods are awesome hacks, but the former is quite power-hungry, while the latter only allows rechargeable batteries to be used (four alkaline AA batteries will supply well over 5 volts and this creates the risk of radio damage).

Although I bought my DR111 almost one year ago, it hasn't been getting much use; in the table-top / external antenna setting, software defined radio applications allow for excellent DRM reception. However, yesterday I discovered one undocumented feature of the unit that makes portable operation really easy: it turns out that DR111 can draw power via its USB port!

NewStar DR111 DRM receiver connected to Gomadic AA battery pack via the USB port
Enter the Gomadic Portable AA Battery Pack with regulated 5V output and its USB connector accessory. No risk of power overload and no need to solder wires and plugs together. Below is a video of DR111 running on four AA alkaline batteries in a local park earlier this morning:

While in DRM mode, I enjoyed listening to Radio Exterior de España and Radio France International (the latter being especially impressive as its signal is rather weak and the time of day didn't allow for good propagation on the corresponding frequency). I also tuned into the final hour of Radio Habana Cuba's morning analogue shortwave broadcast.

One important thing to note is that while there are other portable USB power solutions out there, some of them inject quite a bit of RFI into the receiver because of their switching voltage regulator design. Fortunately, in the case of Gomadic, this artefact isn't too strong and doesn't get in the way of decent radio reception. I look forward to listening to All India Radio's afternoon DRM broadcast on 15140 kHz later today and perhaps I might even catch Radio New Zealand International's DRM signal like this shortwave listener did!

About the author

This blog is written by a shortwave radio enthusiast based in London, UK. You can follow him on Twitter at @LondonShortwave