WSPR-beacon V1 / 200mW / 160-10m / based on Arduino™ & AD9850
Required components:
- a power supply (12V for the PA and 5V for the rest)
- an Arduino™-module (any model with at least 13 digital and 2 analog pins will do / in my case it's a rather big "Uno"-clone only because I had one in spare)
- an AD9850-based DDS module (I got mine for less then $10 incl. shipping / by the way, this fellow is quite noisy at certain frequencies and giving it a bit of shielding isn't a waste)
- some sort of time-source to lock on and keep the beacon synchronized / for this purpose I employ a DCF77-receiver which works fine throughout Europe in a not too noisy environment
- a 2x16 LCD-display (HD44780 clone)
- a PA (there are various design proposals available on the net and it's up to you how much effort you'd like to put into that / mine is 200mW, which I feel is sufficient for WSPR)
- an SWR-bridge, feeding into an algorithm to protect the PA (not a must but definitely helpful when experimenting with various antennas / it's missing in the picture above but was added later on
- 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 / due to my limited space, I decided for an indoor aperiodic antenna
Some links:
- In case you want to program your own beacon based on the libraries I wrote, you may want to take a look at my Arduino libraries (WSPR message generator, control of AD9850/51, DCF77-decoder, ...).
- schematic and source code of the beacon.
- some data around the 200mW PA for 160m-10m (schematic, design tips, ...).
- the stairway to heaven for all that precious RF-power, my broadband aperiodic antenna