Category: News

Home Made Coat Hanger Discone

Reddit user soooooil has posted a series of images showing his home made Discone antenna made out of wire coat hangers and designed for a minimum frequency of 130MHz. His thread discussing the Discone is here.

A Discone is a good general antenna for the rtl-sdr as they are extremely wideband, and can be expected to be useful over almost the entire frequency range that is tuneable by the the rtl-sdr.

Another page on a home made Discone also designed for a minimum of 130MHz is here with some brief instructions links to design calculators.

Homemade Wire Coat Hanger Discone

LNA For All – Wideband Low Noise Amplifier

Amateur radio enthusiast and blogger  has released a new wideband low noise amplifier (LNA) circuit that would work well with the rtl-sdr. It amplifies from 28MHz to 2500MHz with a 1dB noise figure. Check it out on his page here. At 20 Euros plus 5 Euros worldwide shipping for a fully assembled LNA, it is quite a good deal.

This small gadget can lower and improve you DVB-T SDR stick noise figure and improve the sensitivity. Adding the LNA in front the front end of your receiver can open another dimension in your reception. Receiving HAM radio satellites should not be a problem even with the small setup and portable antennas.

LNA For All

Free Virtual Audio Cable Alternative

Virtual Audio Cable is an important software tool for the Windows rtl-sdr user. It allows an audio data stream to be piped from a software radio program such as SDRSharp, into a decoding program. Unfortunately Virtual Audio Cable is not free, which is not in the cheap spirit of rtl-sdr, and at $25 it costs more than the dongle itself. There is a trial version, but it periodically plays a watermark voice which can break decoding.

A free (donationware) alternative to Virtual Audio Cable that we recently found is VB-Cable. VB-Cable does exactly the same job as Virtual Audio Cable but for free. By donating any amount to the developer, you can unlock two more virtual audio devices, which is useful if you use multiple rtl-sdr dongles on one machine.

Note, one trick to installing VB-Cable is that I found that I had to run the installer in Administrator Mode on a Windows 7 machine to get it to work.

ADSB# Plugin for SDRSharp

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Update and Note: This plugin appears to be now dead. If you are simply looking for the ADSB# standalone program (not the plugin), it is located in the SDR# install folder from sdrsharp.com.
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A user by the name of darkscout.rm on the SDRSharp Yahoo group has posted version 3 of his ADSB# plugin for SDRSharp. The main purpose of this plugin is that it allows the waterfall to viewed at the same time as decoding, which may help with visually tuning the gain settings, or experimenting with ways to block out out of band interference. He has also added in a 1-bit error recovery by brute force option, which is used in dump1090 and may improve decode performance.

ADSB# is a standalone program to receive ADS-B signals and my ADS-B plugin does the same but from within SDR#. Continue reading →

2-in-1 RTL-SDR and HF Upconverter on a Single PCB

A Hungarian hardware developer has been working on what appears to be a 2-in-1 software defined radio, combining the rtl2832u and E4000 tuner chips together with a HF upconverter all on the same PCB. The device is able to tune from 1MHz to 1.7GHz, and has two antenna connectors, one for the HF antenna, and another for the VHF/UHF antenna. Using the Google translation is difficult, but it seems the board has a protection diode, 100MHz oscillator, low noise amplifier (LNA), isolation between the two antennas, and also retains the ability to receive DVB-T and DAB broadcasts.

The developers article in Hungarian on this combined tuner can be found here, and a Google English translation here. Another version of the page which looks to be a product ordering page can be found here, and Google English translation here. We aren’t sure if the developer is still shipping these devices as the eBay listings have all gone down, but it seems you can order one by contacting the developer from the website.

Update 27 May 2013: Version 3 of this combined rtl-sdr can be now found for sale at this link. http://janielectronics.com/index.php?route=product/product&product_id=94.

RTL-SDR Combined Tuner

Continue reading →

RTL-SDR Running ADS-B on a Quadrocopter

Blogger John Wiseman has managed to get ADS-B decoding using an rtl-sdr stick working on his AR.Drone quadrocopter. The AR.Drones run on the Linux operating system, so he was able to compile and install the Linux ADS-B decoder dump1090 on his drone.

Although the reception was hampered by RF interference from the drones electric motors, it was still able to pick up a number of ADS-B signals.

ADSB Drone