Category: Projects

Amateur Radio Projects and Software Defined Radio

Adding Streaming Audio to BLUEDUO

This is a follow up video for adding streaming audio via WiFi to the Android based BLUEDUO remote display for the Elad FDM-DUO.This is accomplished by using the Soundwire audio streaming Android app. You must also install the Soundwire server application on a PC or Raspberry Pi. The audio stream from the FDM-DUO can be accessed via the TX USB connection. It is not necessary to run the FDM-SW2 for the streaming audio nor for the use of the BLUEDUO Android app. Doing so will confuse the BLUEDUO app running on your Android device. Once this is setup you can then use the BLUEDUO app and the Soundwire app to listen to and control the FDM-DUO from a remote location in your home as long as the location is in range of your bluetooth and wifi signal.The paid version of Soundwire will give you additional options for tweaking or reducing latency depending of your particular WiFi setup for best performance. However, increasing latency for better streaming performance may make the BLUEDUO’s scope appear a little behind the spectrum / waterfall. It’s best to try to reduce the latency to it’s lowest level while maintaining good streaming audio quality.

Wireless Touch Screen Remote for the Elad FDM-DUO

With the release of the Icom 7300 a few months ago, a built in spectrum / waterfall display has become a very popular idea. The little Elad FDM-DUO when connected to a computer and the FDM-SW2 software clearly trumps the IC-7300 when it comes to the powerful features of PC driven SDR. However, sometimes something simpler might be better at times. This has been the charm of the “no computer needed” Icom 7300.  The Elad FDM-DUO is also a standalone knob and button controlled SDR, but you lose the additional functionality of the Spectrum / Waterfall when operating standalone. Thanks to the hard work of Giavanni HB9EIK in cooperation with Elad you can now add a wireless bluetooth remote control scope to the FDM-Duo using an Android tablet or phone. The remote will allow for touch tuning of the Elad FDM-DUO via the the spectrum /waterfall display as well as change bands, toggle the PTT and Tuning features, and turn on and off various setting like noise Noise Blanker, Noise Reduction, etc. All with no PC required. Since the scope / remote is wireless, it can be placed in a more convenient location or operating position to allow for easier …

The mcHF QRP Transceiver Project

When it comes to a low cost SDR QRP Transceiver W0MKA has the right idea. The mcHF QRP transceiver is a project that W0MKA has been working on for awhile and we are starting to see more of a finished product begin to emerge. W0MKA’s project is pretty much a DIY endeavor at this time. Can you buy it? Kinda sorta. W0MKA makes limited quantities of the unpopulated boards available from time to time as well as the display. This is a project that we would certainly like to see become available as a complete kit in the future or even better a preassembled model. So head over to W0MKA’s website and give him a little encouragement!

Adding ADS-B, ACARS, and ATC Audio to PlanePlotter Using Multiple RTL2832U Sticks

If you are an aircraft monitoring enthusiast, you might have eyed some of the ADS-B radar boxes that allow you not only to receive ADS-B tracking information, as well as ACARS information, and live Air Traffic Control frequencies. These boxes typically go in the $800 range. If you are wanting to experiment with adding these features to your cheap ADS-B station, we can do it for about $40, using two additional RTL2832U sticks. This is of course assuming that you already using a RTL2832U stick for ADS-B  reception with PlanePlotter. If you are using another ADS-B receiver, you can still add the additional two sticks to add ACARS and live ATC reception. I highly recommend that you consider using a RTL2832U stick with the R820T chip set for ADS-B, since it has the best sensitivity in the 1090MHz range. Even used with the included whip, you can typically receive ADS-B signals out to 75 miles indoors or more depending on your location. As we have seen, adding an external antenna can increase the RTL2832U ADS-B reception significantly. This “poor mans” ADS-B, ACARS, and ATC receiver system in no way competes with the $800 boxes, but can work very …

Building an Inexpensive ADS-B Receiving and Sharing Station


ADS-B Aircraft Monitoring can be a fascinating hobby, allowing you to view live tracks of some nearby aircraft within a 100 miles or more in your area. Some hobbyist also like to share their data with networks that provide this information to the general public. ADS-B monitoring can be an expensive hobby with ADS-B receivers alone going in the $200 to $800 range plus the cost of a computer system to process, display aircraft positions, and possibly share the data. Thanks to recent advances is using certain inexpensive Digital Video Broadcast – Terrestrial (DVB-T) dongles as Software Defined Radios, it is now possible to create very inexpensive versions of ADS-B receivers and sharing systems. This article will show you how you can create your own complete ADS-B receiving and sharing station for less than $200. This is done using some inexpensive off the shelf computer hardware and a RTL2832U DVB-T stick. The price of this project can vary greatly depending on what you may already have on hand, what hardware options you choose, and where you shop for parts. This article will try to keep the price around $200 or less. You don’t have to be a computer expert …

ADS-B Sharing Server on a Stick (or a Pi)

Many ADS-B hobbyist like to share data with the public. Their are several sharing services out there that one can use to do this. However, one of the draw backs of sharing data to some hobbyist is having to tie up a large,  power hungry, noisy, and expensive computer to do this. Why not use a small, low power, quiet, cheap computer to do this? Well you can, with either the $35 Raspberry Pi or the $70 MK802. Both units include fanless low power ARM chips to provide the computing power you need in a tiny package. The ARM processors in the MK802 or Raspberry Pi are not very powerful, but they are plenty powerful for ADS-B data sharing. Both systems run modified versions of common Linux distributions that you will need to install. This project is more of a proof of concept and there are probably more details to be worked out depending on the type of ADS-B receiver, how it’s connected to the server (USB or IP), and the data format it sends. The testing was done with a RTL3832u as a receiver with gr-air-modes sending ADS-B data over TCP port 30003 in Kinetics SBS-1 format.…

Softrock RX TX – We have a Reciever!

After several days of working on the Softrock RX-TX kit, I have completed the receiver section of the radio kit. Initially did this did not go well. When I plugged in the rig for testing, I was getting a large ac hum right in the middle of the SDR display. I was receiving signals, but they were very weak. After changing cables and trying several SDR programs, I continued to get weak signals. Since I am using a not so fantastic antenna for 20M, I thought that was the best this radio would do, and I would just have to tune around the hum. I went back over the the receiver section several times checking my work and could not find anything obviously wrong.  After a couple of days, I decided to give it one last look. I suspected the problem could be in the op amp section. Under closer inspection under the giant magnifying glass, I saw a couple of pins on the op amp chip that looked a little suspicious. Often with these small ICs, the pins look like they may be soldered to the board, but they may not be making a good connection. After I re-soldered …