Project 114: VLF Antenna Phase 1 Final Report

I have finally finished phase one of my VLF Antenna Project. I am generally happy with the results, the antenna worked, and I did get some definite radio atmospheric activity from the audio amplifier. However, my attempts to digitise this data have not been very successful.

I attempted to use an Operational Amplifier (OpAmp) to replace the audio amplifier in the speaker, and I connected the output from the OpAmp circuit into the Arduino, but I am not confident that I captured real data coming from the Antenna. I have two large data sets that I am currently attempting to process. Most of the programs I have used can’t handle the large size of the dataset, however, small sections of the data that I have plotted look ok. I will continue my attempts to replicate the observed trace using the data I have saved.

I have been using gnuplot to plot the data, and it seems to be able to process it ok, but presents it as as squashed block of red lines. I need to figure out how to space it out more before I can make use of it.

I did see one bizarre signal while recording the trace, which lasted several seconds. It seemed to be some man-made signal however, it looked too ordered and consistent to be natural. It could have been a radio transmission from a boat or a plane, or something of that nature. I will analyse it further if I can isolate it from the data.

The signal output shown below is the normal background radiation picked up the the antenna, there is nothing particularly unusual going on there.