Antennas

Residency at Hangar EMF performance

A 2 weeks Residency research at Hangar.org in colaboration with Merche Blasco, sound artist and composer. The result was a live multichannel performance using the electromagnetic activity of Hangar and inviting the audiance to use antennas to interact with the EMF of the space. The antennas were made by the particpants of the wearable sound workshop we held at Hangar.

Inspiration to create a tunnable device to search for different frequencys:

Using old Am radio coil  and pyrite to modulate the frequency reception

"The tuning of the radio can be set with a dedicated multifunctional Search control which acts both as a manual CV source and as an input attenuator for an incoming CV signal dedicated multifunctional Search control which acts both as a manual CV source and as an input attenuator for an incoming CV signal"

<iframe width="560" height="315" src="https://www.youtube.com/embed/Kgh5qOpsfkM" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

Making a textile tunner with KOMA Field Kit and electronic textilesMaking a variable sensor schematic for KOMA field Kit

Using light sensor to tune to different radio frequencys

Filter freqencies too get rid of too much AM radio reception with LM386 amp.

"The input wires (together with the traces going to the input of the LM386, and LM386's own input capacitance) form a parasitic antenna + resonant LC tuning circuit, which, by chance, has a resonant frequency very close to the station frequency you're listening to. These signals are amplified by 20 (accordingly to your schematics). The small non-linearity of the 386 might act as AM demodulator.

A small capacitor (e.g 6.8 nF) will kill the incoming RF signal, by forming a low-pass filter with the two 1-k Ohm resistors (while passing the full 20kHz audio signal. Actually, if you connect both signals, i.e. if you don't leave one channel open, the bandwidth will be 40kHz). For best effectiveness, put that capacitor (and the two 1-k resistors) close to the input of the LM386."

https://electronics.stackexchange.com/questions/327426/how-does-a-lm386-audio-amplifier-become-to-a-radio-receiver

https://www.mikroe.com/ebooks/radio-receivers-from-crystal-set-to-stereo/simple-radio-receiver-with-lm386-ic

Experimenting to make a homemade variable capacitor with the local spanish fan

Antenna

Calculate spider web coil http://makearadio.com/coils/spider.php

Gauge calculator: https://www.rapidtables.com/calc/wire/awg-to-mm.html

Loop Antenna (for magnetic reception)

The antenna improves reception of weak or interfered stations in several ways.

spider web antennaDirectional antenna with basket weave technique

Calculate the desired frequancy for an optimal antenna reception

The theory for calculating the loop is very simple.The circumference of a magnetic loop is 1/4 wave of the designfrequency.

Example for 14 MHz.

300 / 14 MHz = 21.428 m is 1 wave

21.428 / 4 = 5.357 m is 1/4 wave circumference

5.357 / 3.14 = 1.706 m diameter.

The recommendations are that you can tune the loop from the design frequency to the frequency divided by 2 to keep the effiecency acceptable.

14 MHz / 2 = 7 MHz

Frequency Allocations

freq allocation EU http://www.rfcafe.com/references/electrical/rf-freq-allo-euro.htm

https://www.ecodocdb.dk/download/2ca5fcbd-4090/ERCREP025.pdf

Wearable Sound Workshop

2 days workshop with Merche to make a wearable synth and antennas

Merche Blasco textile circuits

An electromagnetic walk

Antennas

EMF performance