Архив за 30.10.2019

Comment on An Active Low Cost HF Loop Antenna Made in the UK by Norea Armozel

It’s nice to see an entry level active loop in the market now. I’ve been just building from schematics with varying success (more to do with me than the circuits I’m guessing). So I’ll definitely look into buying one of these for comparison.

[Update] Listening to university lectures directly over headphones with the help of an SDR

Hello everyone, after the past two posts asking for advice on how to to directly hear the professor’s mic signal over headphones, and a bit of messing around myself here’s an update as to what I’ve reached, and a guide for those wanting to do the same.

Previous posts:

1- https://www.reddit.com/r/RTLSDR/comments/dio2af/intercepting_professors_microphone_signal_in_a/

2- https://www.reddit.com/r/audio/comments/bqvuu2/is_it_possible_to_intercept_and_mirror_the_mic/

Background: I’m studying the the TUM (Technical University of Munich), and its very likely that the same method works for many others in Germany and around the world. TUM uses *wide band FM at around 500-700 MHz. Every lecture hall has three defined frequencies *that are written on the professors desk.

Concise guide for those who just want to get it done

1- Buy an RTL-SDR Dongle and an antenna. I bought this one but you can also buy this one for better portability. You only need a very small antenna, the signal is so strong that I can even hear it clearly without an antenna (I’m really not sure how this works)

2- For PC: Download SDR#, and your dongle’s drivers

3- Enter frequency on the upper right and choose Wide Band FM Demodulation (or Narrow Band if that works better) Note: This will be different depending on what system your Uni uses.

Guide for those who want to use it on their android phone

1- Download RTL-SDR Driver and SDR Touch from the Play Store

2- Open the driver app once, then open SDRTouch, go to settings and change source to RTL-SDR instead of HackRF

3- Connect Dongle using a USB-OTG Cable like this

Battery life fix (work in progress) Since the dongle uses a lot of energy, it drains the battery. In my experience, a 90 min lectures streamed to bluetooth headphones drains about 750 mAh from my phone (about 20% of my phones battery), this is enough for a Uni day, but the constant drainage And recharging with kill your battery very quickly.

For that, I recommend buying a power bank and a usb y cable (that splits power and data) so that you can power the dongle without draining your phone. This cable already comes with the portable Nano bundle.

Latency Bluetooth headphones cause significant latency which can be very annoying, therefore it’s recommended to use wired headphones or well isolated headphones to not be bothered by the “echo”

Why not just talk to the university’s accessibility office and have them sort out all of this for you? Because in my case I think it’s more of a luxury than a necessity to hear a lecture over headphones, and I’m not hard of hearing so I didn’t want to involve the accessibility department in this. Plus the project was fun.

Thanks for the help and advice, and I hope this post is useful for anyone trying to do the same thing.

submitted by /u/tinclan
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Comment on Dash Mounted ADS-B With an RTL-SDR Blog V3 by junta

Seems a bit stupid really.

Comment on Dash Mounted ADS-B With an RTL-SDR Blog V3 by Anonymous

What would you do if you had an SDR installed in your vehicle?

I would pay attention to driving.

Comment on SignalsEverywhere: Testing Wideband PCB Antennas from Hex and Flex by WacKEDmaN

his vivaldi antennas start at 800Mhz and the spirals start at 300Mhz… thats a long way from 10Mhz!

SignalsEverywhere: Testing Wideband PCB Antennas from Hex and Flex

In the past we've posted twice about Hex and Flex who has been designing and selling various types of wideband PCB antennas. Previously we saw his wide band 10 MHz to 3.5 GHz vivaldi antenna, and his wideband 400/800 MHz+ spiral antennas.

Now on the latest episode of SignalsEverywhere host Corrosive gives us a brief review of the Hex and Flex antennas, and goes on to demonstrate the spiral antenna in action. In his tests he was able to receive Inmarsat AERO, 433 MHz tire pressure monitors (TPMS), 300 MHz APRS signals, 300 MHz SATCOM, 800 MHz P25 and 1090 MHz ADS-B aircraft tracking signals with the spiral antenna and our RTL-SDR Blog Wideband LNA.

The video also comes with a 20% off promotion code for the Hex and Flex Tindie store. Simply enter the code "signalseverywhere" at checkout.

RTL-SDR Inmarsat, UHF Satcom, P25 and Portapack Hex and Flex Antenna Review

Dash Mounted ADS-B With an RTL-SDR Blog V3

Reddit user [Bobcalamarie] recently [posted] about how he uses his car dash mounted Android tablet along with an RTL-SDR Blog V3 and a magnetic mount antenna while sitting in traffic to track aircraft overhead.

We’ve seen something similar to this once before when [Signals Everywhere] uploaded a video showing off ADS-B reception (among other things) to a dash-mounted Windows tablet and an Android head unit.

The software used by Bobcalamarie is the Android [Avare ADS-B] software which can be found in the Google Play Store. However, other applications exist for Windows, Linux, and other operating systems as well. Some software such as [Virtual Radar Server] even allows you to set-up alerts for specific types of aircraft. Which while we wouldn’t condone it, it might come in handy for someone in traffic.

What would you do if you had an SDR installed in your vehicle? We would love to hear what you have to say in the comments below.

Dash Mounted ADS-B Reception

KerberosSDR • Raspberry Pi 4 Compatible Image Released

Just released a ready to use IMG which should be compatible with the Pi 4 (and backwards compatible with the Pi 3/B+). Please feedback here if there are any issues.

https://drive.google.com/file/d/14AVWcN ... sp=sharing

Statistics: Posted by rtlsdrblog — Wed Oct 30, 2019 12:52 pm

KerberosSDR • Re: Current Issues and Changelog

Server 1.5 For Raspberry Pi 4:

IMG V1.5 for the Raspberry Pi now works on the Pi 4 too.

https://drive.google.com/file/d/14AVWcN ... sp=sharing

Statistics: Posted by rtlsdrblog — Wed Oct 30, 2019 12:51 pm

Comment on Decoding the ARES Train Protocol with an RTL-SDR by moneriomaa

hi everybody
i work on new GUI for decoding tetra and other trunked radio by rtl-sdr
my plan and road map is shown at github OpenEar
everybody can be part of this project!
thanks a lot

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