DrVarnik on YouTube has posted a tutorial video on how to receive, decode and plot AIS information. The Automatic Identification System (AIS) is a system used for automatic tracking of large ships and passenger boats. It is a similar idea to tracking aircraft with ADS-B. His method uses a RTL-SDR for receiving the AIS signals with SDRSharp, decoding received signals with AISMon and plotting the decoded information with OpenCPN. He uses VB-Cable for looping the audio from SDRSharp to AISMon, but if you have a ‘Stereo Mix’ or equivalent feature with your soundcard, that will be unneeded. Best results will be achieved using a narrow-band vertically polarized antenna tuned for 161.975 MHz and 162.025 MHz (marine VHF). A directional antenna would also likely be a benefit. You can find some designs to try lower down the page. For safety, please only use this guide on land! Wouldn’t want you getting lost at sea.
Over on the RTL-SDR Facebook Page, Boris Lukac has shared a link to an Instructable by tigers58 for a omnidirectional fractal HDTV antenna. The simple build covers 50-1100MHz making it perfect for general use with a RTL-SDR and for grabbing some extra HDTV channels when not hooked up to your dongle. The supplies needed to build the antenna may already be laying around your home or workbench:
A piece of poster board or suitble material
Printer with paper to print out the pattern PDF
Tape
Scissors
Thumb-tack (or other sharp pointy tool)
10.5 ft of 22-24 AWG copper/aluminum wire
Crimp connector and tool to crimp with
A length of 300 Ohm Twin Lead, or, an in-line 300 Ohm to 75 Ohm matching transformer (tigers58 also states he has had success with just directly connecting RG-6 coax to the antenna leads)
Other tools such as a screwdriver for attaching the antenna leads to the matching transformer and craft knife or other small sharp blade for cutting slots into poster board.
“After reading an article about the use of fractal mathematics in the design of cell phone antennas that have incredible bandwidth in spite of their extremely small size, I began to experiment with using a very simple fractal pattern, the Koch Snowflake, as the basis for an easy to build indoor HDTV antenna. The result of that experimentation is presented here as what I believe to be not only the best DIY HDTV antenna, but the also the simplest to build, not only in terms of the materials needed, but also in the labor required. As the holder of an Extra Class amateur radio license, I know there is no such thing as a “magic” antenna, but I started referring to this antenna as the magic antenna when I discovered that it had such amazing bandwidth, covering digital channels 2 through 60. So, with that in mind, let’s get started.” — tigers58
With many people already having these items on hand, this could be a quick cheap project to help increase the signals you are able to pick up with your RTL-SDR Dongle. Be sure to check out the Instructable page for all the steps needed to build this antenna. Keep in mind, with a wideband antenna like this, it may introduce more noise. Depending where you live and what is around your antenna, your results may very. Keeping the antenna flat may also allow for more directionality while reducing noise from sources out of the direction you wish to receive.
Messing around with a EzTV645 W/ the RTL2832U and FC0013 Tuner Chip. Software being used is SDR# (SDR Sharp). I’m having some issues like getting mixed FM boardcast signals no matter where I’m at and multiple images of the same signal. I was told this was normal but I messed something up while soldering in a pig tail to replace the current RF connector. Too sensitive to ESD See for more information – Source
Messing around with a EzTV645 W/ the RTL2832U and FC0013 Tuner Chip. Software being used is SDR# (SDR Sharp). I’m having some issues like getting mixed FM boardcast signals no matter where I’m at and multiple images of the same signal. I was told this was normal as I thought I messed something up while soldering in a pig tail to replace the current RF connector. See for more information – Source
“Monitoring 433.9 MHz – picking up plenty of local weather temperature sensors and the likes. Using a newsky dvb-t tuner and a modified version of gqrx that supports rtl sdr. Antenne is a 2m/70cm in my attic.” — trylleklovn
“I have been getting into software defined radio via RTLSDR and found the stock antennas woeful for reception and picked up a tonne of noise from my LCD and laptop – though it’s hardly surprising. So to improve the situation and spend as little as possible I decided to make a discone antenna. After some research I happened upon VE3SQB’s site and a neat discone design program for Windows. As a compromise between frequency and unwieldyness I settled on 130MHz as the lower bound. Discones are inherently wideband and I expect the antenna to be useful for reception in the 60MHz to 1700MHz band the E4000 tuner can work with.” — http://helix.air.net.au
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