Ham radio
"WSPR meets GPS" -> WSPR-beacon 2.0 with GPS-based time synchronisation and
calculation of QTH-locator is now available.

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

Some impressions showing the typical "yield" throughout Europe on an average 2016/17 winter day as well as some DX-highlights.

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 "coined" 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, feeding into 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 solution to that,
  an indoor aperiodic antenna, is also available here.

Some stuff worth sharing:

- Arduino-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
  (Version 3.0 with improved decoding algorithm now available)

- schematic and source code of a beacon ready-to-transmit  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