Triangulation of a VHF signal

No directional antenna for triangulation ? Heatmap of geographically sampled signal strength is a pretty good alternative:
▻http://theanatomize.blogspot.no/2014/07/locating-source-of-signal-with-rtl-sdr.html

http://4.bp.blogspot.com/-FPE39rsGQBc/U9nEnpQfKTI/AAAAAAAAALs/wttJoIRT-WQ/s1600/signal.png