| German Amateur Radio Club |
www.darc.de (german language) |
| Local Club C25 – Erding |
www.ov-erding.de (german language) |
| QRZ Callsign database |
www.qrz.com |
| QRP-Labs Transceivers, WSPR, GPS, Filters, … |
www.qrp-labs.com |
| Smart Radio Concepts Charly 25 SDR Transceiver |
www.smartradioconcepts.com (german language) |
| GQRP Club Low Power Radio Club |
www.gqrp.com |
| AGCW Activity Group CW (Telegraphy) |
www.agcw.de (german language) |
| SKCC Straight Key Century Club |
www.skccgroup.com |