I was looking for a simple project to split a RX antenna into two receivers, my Wellbrook loop feeds my Kiwi SDR and also my HF radio. The Wellbrook loop is very capable at LF and MF frequencies, and so makes a great alternative for RX on 472 KHz and even NBD reception should my […]
70 MHz Cumulative #1
This was our first opportunity to go portable VHF this year, making the most of a very warm February afternoon. The RSGB run a series of contests thought the year, and this was the ideal opportunity to put on the club call M0SNB. We operated from the Secret Nuclear Bunker near Kelvedon Hatch, using the […]
Exploring Network Radio with the Android 7S Plus
Network Radio is VOIP and not traditional RF radio, but it does share a number of things with traditional radio. Starting with the software, Zello provides a channelised platform and this has been adopted by amateurs to provide a starting point for activity. Radios are available from £80 to £199 online. The software can be […]
Receiving GMDSS messages (Part 2)
Part 1 discusses getting started, Part 2 looks at the messages received. Many of the messages are simply “TEST” messages, this is because it is mandated the systems must be tested at regular intervals. The positive side is the number of messages being exchanged is quite high, and so it doesn’t take long to record […]
Monitoring (GMDSS) Global Maritime Distress and Safety System
GMDSS send messages on the HF and VHF bands using Digital Selective Calling (DSC). The system utilises a number of HF and VHF frequencies to provide global coverage. 2187.5 kHz 4207.5 kHz 6312.0 kHz 8414.5 kHz 12577.0 kHz 16804.5 kHz Ships at sea are required to monitor 2187.5 and 8414.5 but often monitor all of […]
Broadcast Overload on Kiwi SDR
The Kiwi SDR and Wellbrook loop provide a very good single antenna solution for 0 to 30 MHz shortwave reception. The Kiwi is capable of displaying the complete band of 30 MHz, but the disadvantage is the very high power from some of the LW and MW stations can cause the receiver to overload in […]