LF: Portable VLF/ULF recording system with PPS+NMEA

[DK7FC <selberdenken@posteo.de>]

Hi all,

I've completed my portable VLF/ULF(audio) recording system.
See: 
https://dl.dropboxusercontent.com/u/19882028/ULF/VLFesULF%20portable%20recording.jpg 

The system consists out of a:
- Raspberry Pi 2B
- DC/DC converter with a 5.0V output (80% efficiency)
- 7 Ah lead acid battery
- Stereo input soundcard
- 32 GB USB stick
- NEO-6M GPS module (including antenna)
- (shut down button)
- (switch for starting/stopping a recording)

The latest add-on, the GPS module now allows to record 1PPS impulses and 
NMEA data for most accurate and glitch-free(corrected) recordings, 
absolute timestamps as well as location data.
The recording is stred as a wav file to the USB stick directly.
It consumes 160 mA at 12V during a record. With the battery it should be 
no problem to record for nearly 2 days.
Future ULF reception tests can now be done with this improved technique...

73, Stefan