Project:Hacktenna
From London Hackspace Wiki
The Hacktenna was build by the Ham Radio hackers on the 1st of June 2013.
It is a random length wire (with random length being around 20m) hanging about 1m above the fence, and insulated from the transmission line by a ferrite choke with five loops of wire. The antenna can be easily tuned with an ATU in most HF bands.
Orientation is roughly N/S, so we hope to be able to communicate on the E/W direction (which leaves out Africa, unfortunately).
We did two way contact with Italy, and heard several stations from Russia, Germany, and the UK.
Photography by Vic (M6BOK), used with permission.