The intend of this site is sharing electronics and Amateur Radio projects that I design or built for myself and make available the information to other radio amateurs interested in building similar projects.
It is my aim providing affordable designs both from the price and from building difficulty perspective. I like to make a project or a design with a clear conscience that, at the end of my efforts, the project & product should be available to other fellow amateurs at the most affordable price.

In addition to the information available on this site, you can check the EA4FRB Blog for more projects and comments.

Kindly send me your comments about the current projects and suggestions and ideas for development of new design of your interest to continue my efforts to provide useful projects to amateur community.

Short Bio

I have been interested in electronics and started operating CB band and homebrewing my own equipment since my teens. This early interest in electronics led me to become an engineer. I have been working as engineer since 1987 mostly in the payment terminals industry. After some time away from the ham activity, I got my current callsign in 2009. I'm active in HF and 6M mostly in digital modes and also enjoy exploring the radio spectrum looking for utility stations, NOAA weather satellity pictures, etc. My main interests are designing and homebrewing my own equipment.

Station Info

  • Name: Melchor Varela
  • Call sign: EA4FRB
  • QTH: Madrid, Spain
  • Locator: IN80CK
  • Memberships:
    • ARRL - American Relay Radio League
    • EPC - European PSK Club - #6906
    • 30MDG - #2648


  • Rig: Yaesu FT450-AT
  • Digital interface: SignaLink USB
  • Power Supply: Sharman SPS9250
  • Multiband Receiver: AOR AR8200-MK2
  • Antenna Analyzer: SARK100, SARK110