[time-nuts] Beaglebone NTP server

David J Taylor david-taylor at blueyonder.co.uk
Wed Dec 10 10:50:07 EST 2014

Hi David,
Yes, You mean the hourly dips? That is caused by the the VLF receive
software that
is running on the same PI. It makes hourly recordings of DC to 24 Khz
with a USB soundcard. The CPU is running at max capacity most of the

Perhaps it is now time for a dedicated PI, that only has the task of
playing Stratum One.

If anyone is interested:

73, Frits W1FVB

Yes, that is quite interesting, Frits, and of course the hourly dips are 
just as you say.

I take it that the spectrum is from a broadband antenna, and that the graphs 
below are signal strengths of specific stations?  Perhaps you have a 
description of the project.  Perhaps link that description from the text:

  "Raspberry PI Project by W1FVB"

RPi cards have a way of proliferating - I have seven now!  At least two are 
actually doing something useful (ADS-B receiver with a DVB-T dongle, and a 
wall clock driven by NTP).

David GM8ARV
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor at blueyonder.co.uk 

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