Here is an old ham radio operators trick for cleaning wires for soldering that are old and corroded. It is hard to find this technique printed anywhere!
Extensive review of the Yaesu FTDX 3000 HF top class transceiver by Yaesu
How to compile and configure WSPR on a Raspberry Pi
VHF Power amplifier VLA 200 english manual
AX.25 Packet Modem homebrew project on Arduino
Schematic diagram of the VLA 200 power amplifier by RM Italy
The project is an AVR ATMega328P based AX-25 1200 AFSK Digital Repeater, suitable for APRS digipeating
Schematic images in CAD format and circuit diagram to make your own programming cable for the Yaesu FT-7900E
Setting up UI-View 32 with APRS-IS servers
The WhereAVR is a small, lightweight, low-power, and low-cost APRS tracker with a full compliment of analog and digital I/O, as well as the ability to decode ax.25 packets. This allows for the reception of remote commands without the need for a real TNC.