After 3 days from a openly generous workshop, here below I try to collect some of the audio, pictures and g.p.s files that made part of my process following the schedule openly proposed by Martin Howse.
[notes by Alejo Duque]
On friday the 4th I had the chance to take the train at Schonhauser Alle, it took me 2 stops to have the Audio recorder and the first handmade hardware that used a coil as an antenna hokked together. I started recording while in the subway and had my G.P.S ready. When i finally got out the underground it was just in front the big Alexa shopping center. It took a while for the device to report my position but when i finally got one the trip continued. Below are some images from the place along with a 55min. audio track that can be paired with the place (latitude, lomgitude) via the timestamp in the G.P.S log.
Listen here the audio recording from the walk around the area of AlexanderPlatzs that is also depicted below via an image og google earth generated on the log from a G.P.S that was also carried around: http://www.archive.org/details/EmfAtAlexanderPlatz
In case you want to follow the whole audio see also the waypoints, (image below) they have names according to the Minute in the timeline on the recorded soundtrack.
After 3 days of workshop we manage to build 3 different boxes:
device #1 the fisrt one a simple one based on an amplified coil running on 9volt batteries and allowing us to capture a wide range of “waves” including those from radio, there where moments when one could listen to radio stations, here is a short sample (Play LOUD!!): http://www.archive.org/details/EMF_radio_voices
device #2 our second box is an improvement to the design used in the first one, it offered an antenna and actually we soldered coaxial(?) cable following the calculation lambda=c/f for the case of 2.4ghz (wireless protocols a,b,g..) it gave us a 12.5cm cable. The sound file from: http://www.archive.org/details/EmfAtAlexanderPlatz was recorded before i soldered the antenna, i will like to test soon the device with the improvement to see how much gets captured or out.
here is a video using device#2 and a HSDPA broadband router: http://vimeo.com/1416877
Below you can see the first 2, one in the horizontal plane (#1) the other one in the vertical one (#2)
2400000000 que equivalen a la freq de las redes wireless comunes 2.4ghz
300.000.000 meters/sec = c (speed of light) - la velocidad de la luz en metros por segundo
usamos esta formula para calcular el tamaño de la antenna:
lambda (wavelenght) = c/f (freq. in hertz)
este seria el tamaño de la antenna, de los cuales 6.2cm esta descubiertos como se puede apreciar en la imagen 0.1249 meters = 12.5 cms → wireless
device #3 this one is a little bit different since, instead of capturing waves, it produces them. In my view this is like a little EMF contaminator if that is possible to say. The reason why this one can be of good use lies behind the fact that its generated field serves in a more controlled way to arrive to wider area of waves hence sounds. Martin performed with it using a radio a 1.5km coil to conduct(?) the field and device#1 to amplify the captured waves.