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200mW WSPR-beacon for 160m-10m, based on Arduino™/AD9850

The pictures above show the typical "yield" of my beacon throughout europe on average 2016/17 winter days as well as some DX-highlights and snapshots of the hardware itself. Ok, wiring and the arrangement of the look a bit makeshift but hey, I'm only an Electrical engineer, life is short and after all, RF-design follows it's own rules ;-)

Components of the beacon:

- a power supply (12V for the PA and 5V for the rest / external or built-in, whatever is at hand)
- an Arduino™-module (just any will do / in this case it's a rather big "Uno"-clone only
  because I had one in spare)
- an AD9850/51-based DDS (mine was "minted" in China and came for less then 10$ incl.
  shipping / by the way, this guy is quite noisy at some frequencies and giving it some sort
  of metal case is probably a good idea and I plan on doing that later)
- some sort of time-source to keep the beacon synchronized / for this purpose I employ a
  DCF77-receiver but the most common solution outside Europe is probably a GPS-module
- a LCD-display (here it's a HD44780-clone from the same source as above / this module
  is not a must but kind of nice to have)
- a PA (there are various design proposals available on the net and it's up to you how much
  effort you want to put into that)
- an SWR-meter (also not a must but definitely helpful when experimenting with various
  antennas / it's missing in the picture above but was added later on mainly to drive an
  algorithm protecting the PA in case of a mismatch
- last not least the antenna / if the beacon is set to operate on a number of (or even all)
  bands, a decent broadband design will be required / information on my approach to that,
  an indoor aperiodic antenna, is given further down

Some stuff worth sharing:

- C-libraries  supporting generation of WSPR-codes and control of the AD9850 including
  some sample code (a simple WSPR-beacon) / particularily useful to simplify writing your
  own Arduino™ code around WSPR and DDS

- my DCF77-signal decoder library  turning your Arduino™ into an atomic clock

- all schematics and the source code of my beacon  if you just want to get into the air
  quickly and programming isn't sheer fun for you

- some data around the  200mW 160m-10m PA  (schematic, design tips, ...)

- the stairway to heaven for all that precious RF-power,  my broadband aperiodic antenne