During the summer break it became quite here on my blog. While Instead of chilling at the beach, I spend a lot of time on new Hardware and Software projects. Most of them are done, and now it’s time to document them. In this blogpost I want to share the construction of a versatile 4:1 Balun. In combination with ladder line and an automatic Antenna tuner you can use any dipol on almost all frequencies.
Over the last years I spent a lot of time simulating antennas. One annoyance I encountered over and over was the unavailablity of values for ground conductivity and the relative permittivity. Two figures which have quite an impact on the antenna performance, especially on vertical antennas. This finally led to the conclusion that both figures need to be measured. In early 2012 I built a measurement kit and finally determined ground conductivity and relative permittivity at our contest station.
The community of Flex-Radio enthusiasts which select the DJ Console as their main user interface is steadily growing. Community members are sharing pictures to make it even better. After several labeling solutions, a recent discussion on the PowerSDR-UI Yahoogroup ended up in an haptic improvement for the DJ Console’s tuning wheels.
Where ever I operate contest in a multi transceiver environment interferences between the 40m and 20m are guaranteed. An easy way to reduce interferences are coax stub filters. Dave, K1TTT has a great website with a lot of useful technical resources. One of them is dedicated to coax stub filters. After building up two sets of stub filters (one in Namibia at V55V and the other one in Spain at ED1R) it’s time to document it.
In untrusted environments like open WiFi Hotspots you want to tunnel your traffic through an encrypted channel to the internet. Last year Firesheep has proven successfully how dangerous surfing in a public, non encrypted hotspot can be. A Virtual Private Network (VPN) can also be used to access internet services with IP Address restictions (e.g. Video or Music streaming services like Netflix, Hulu or Spotify). In this post I’ll show you a VPN solution which can be easily set up and used. The tutorial will work with the Windows and Mac OSX.