HFZone International Radio Hobbyist Group
Posts with the tag sdr:

RTL-SDR vs Nooelec Upconverter vs Airspy HF+ Discovery

I’ve been using the RTL-SDR dongle and a Nooeelc HamItUp+ Upconverter for the better part of a year for various projects and shortwave listening. I think they’re great devices, especially for the price point. Recently, I purchased an Airspy HF+ Discovery in an attempt to upgrade my listening experience, particularly on the HF / shortwave bands. The following is one of many tests that I’ll be conducting to compare the three devices. Setup: RTL-SDR v3 Nooelec HamItUp+ UpConverter Airspy HF+ Discovery 9:1 balun Fencetenna connected to balun with wires as follows: 1x 100ft 16 AWG wire that is 2ft off the ground 1x 100ft 16 AWG 6ft off the ground with another 100ft 22 AWG magnet wire extension that is attached to the second story of my house at about 20ft SDR-Console V3 One caveat is that my tests are in no way scientific and it’s mostly based on my experience with signal, noise, and audio.

An Alternate Way of Viewing Eibispace Shortwave Broadcast Schedules

If you have not tried some of the different ways to browse and parse radio schedule data, here is your chance to follow along. First, you are going to want to install Java from https://www.java.com/en/download/win10.jsp (I use Windows 10. Download the version for your operating system.) Then you are going to want to pull down the schedule in a special format to manipulate later on in this post. You can get it here http://www.eibispace.de/dx/eibi-radioexplorer-a20.zip . DO NOT UNZIP OR EXTRACT THE ZIP FILE FROM eibispace.de. Next, download Radio Explorer fromhttp://www.radioexplorer.com.ru/en/download.html . Unzip and extract this zip file to the same folder with the eibi-radioexplorer-a20.

Military Communications (Click to Show Video)

EAMs are frequently read on the HF-GCS frequencies and usually won’t take you long to hear one. They begin with a 6 letter header, this preamble could have a few different uses, but NPS states for Minuteman Missile launches “The preamble told the crew which edition and page number of a non sealed authenticator to use. Once at the right page the crew would know what message checklist to use.” The receiving crew has access to an emergency action checklist binder where the message and instructions are copied to. Then the message continues afterward and is repeated.