Small portable digital amateur radio station

Nowadays it is very easy to realize radio operation for on the way with a small, portable, amateur radio station. Despite their small dimensions and low weight, such systems are extremely powerful, especially with digital radio operation. They are predestined for holiday, in a hotel, a short break while hiking or for SOTA activities. As antenna i use a Alexloop or long wire.

An Elecraft KX2 is used as a radio. The software (e.g. WSJT-X) runs on a Raspberry PI3B+. As screen I use an iPad Pro 10.5 with Smart Keyboard. In radio mode I activate the personal hotspot on the iPad in which the RaspPi automatically dials in after starting the operating system. The RasPi can then be operated with a VNC viewer app in IOS on the iPad.

As power supply I use the original lithium ion batteries in the KX2. The RasPI is powered by a PowerBank. With a transmission power of 5 watts, radio operation is possible almost all day.

So that the RasPi doesn’t get too hot and to avoid unnecessary power consumption by an electric fan, the case for the RasPi is made of aluminum.

For my first attempts I used a Signalink USB soundcard interface. It actually worked fine. But a radio friend told me that the supply voltage of the RasPi with 5 Volt may be too low for the Signalink and that there might be interference with the digital transmission signal. He recommended me a cheap, external soundcard from Sabrent AU-EMAC. I am thrilled. Once again much smaller than the Signalink interface, the Sabrent works perfectly with the RasPi.

The radio friend also pointed me to an interesting website which describes in detail how to control and optimize the soundcard and radio transmission. This is very recommendable.

Setup RasPi for digital ham radio

vy 73, Karl-Heinz DL1GKK

Elecraft KX2

Sunfounder Raspberry Pi Case Alu

Sabrent USB Soundcard AU-EMAC