Month: June 2012

Amateur Radio Projects and Software Defined Radio

The Raspberry Pi and Ham Radio

Earlier this year the Raspberry Pi Foundation released a small inexpensive computer called the Raspberry Pi. The Raspberry Pi is about the size of a credit card, but yet is a fully functional computer. It has a HDMI monitor output, 2 USB ports, a network interface (optional), SD card slot, audio output jack (no input, but does work with external usb audio interfaces for input). The Pi also has a GPIO interface (General Purpose Input Output), which should be of great interest to hams, because it can be used to interface to external hardware such as relays. All this for a whopping $25 dollars without the network interface (Model A) and $35 with the network interface (Model B). The Pi uses a 700 MHz ARM processor with a Videocore 4 graphics processor capable of Blu-ray playback. The system runs of 5 volts using a USB power supply that connects via a Micro USB jack.…

New Alinco DJ-X11 Firmware Update Out

One of our readers gave me a heads up (Thanks Mark!) that version 2.60 firmware update is now out for the Alinco DJ-X11 is now out. As far as what it does is pretty cryptic. The descriptions says “Three minor bugs fixed. (Squelch level changes after Flash-tune, Programmed-scanning / band-transition parameter relation and a small inconvenience in display)” Maybe someone will know what those issues were. I tried to update my DJ-X11 and had very little success. The problem is that when I start the firmware update program, I get an error message that says something to the effect that MSCOMCTL.OCX is not registered. This is very similar to the problem that we ran into with the control software problem that was mentioned in an earlier article here. Apparently, Alincos software must be developed on a Windows 98 platform.  If you are running anything newer  than 98, you may very well run into this issue. If anyone has any luck with it, let us know!

The firmware can be found at Alincos Website.

Discuss on Alinco DJ-X11 Forum

The RTL2832U / Elonics E4000 SDR Radio – AKA “The $20 SDR”

There has been a pretty good buzz about the “$20 SDR Radio” since the good folks over at Osmocom figured out how to convert a $20 DVB-T  usb dongle into an SDR radio using software only. I decided it would be worth spending the $20 bucks to see how well the DVB-T dongle worked as a Software Defined Radio. Did it work? Yes, but your mileage will definitely vary on this project. Using a RTL2832U DVB-T stick is still in a very highly experimental state. Here is what I found out about the “$20 SDR Radio”

The DVB-T Stick

First of all, not just any ole digital TV tuner stick will work. Supposedly the best ones are based on the RTL2832U / Elonics E4000 chipset. These digital tuner sticks are not designed to work on the US digital TV broadcast standard. So, that means you probably won’t be able to buy one in the USA. The easiest way to find one is just go to Ebay and search for SDR Radio. You will get a list of vendors selling these sticks listed for SDR use at about $20. Be sure to check that the stick is using the RTL2832U / …