VK2DX's blog

With the arrival of Tronson RF attenuator (model RA1728A)
I was finally ready for more low power experimenting.
Easter Friday afternoon was ideal time to tune into 40m WSPR.
An email notification about experiment was sent to LF reflector
and couple of locals quickly joined in.

The very frist transmission was done with barefoow Genesis G59 transceiver running 10 mW:

10 milliWatts

2011-04-22 02:32 VK2DX 7.040060 -18 0 QF56oe 0.01 VK3DB QF31dt 657 221
2011-04-22 02:30 VK2DX 7.040062 -6 0 QF56oe 0.01 VK1DSH QF44ms 253 231

The G59 10 milliwats signal was an easy decode over the distance of 657Km
so power was immediately reduced to 1 milliwat (10dB attn)
Signal at this power level was barely detectable at VK3DB, but good enough for decode at -29 s/n.

1 milliWatt
Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
2011-04-22 03:12 VK2DX 7.040060 -15 0 QF56oe 0.001 VK1DSH QF44ms 253 231
2011-04-22 03:10 VK2DX 7.040059 -29 0 QF56oe 0.001 VK3DB QF31dt 657 221

With additional 10dB attenuation and 100 microwatts output,
the signal was still an easy copy over the distance of 253 Km by VK1DSH.
Actually, Dale decoded almost every transmitting sequence!

100 microWats

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
2011-04-22 03:50 VK2DX 7.040060 -20 0 QF56oe 0.0001 VK1DSH QF44ms 253 231
2011-04-22 03:48 VK2DX 7.040060 -19 0 QF56oe 0.0001 VK1DSH QF44ms 253 231
2011-04-22 03:44 VK2DX 7.040060 -24 0 QF56oe 0.0001 VK1DSH QF44ms 253 231
2011-04-22 03:42 VK2DX 7.040060 -23 0 QF56oe 0.0001 VK1DSH QF44ms 253 231
2011-04-22 03:40 VK2DX 7.040061 -21 0 QF56oe 0.0001 VK1DSH QF44ms 253 231
2011-04-22 03:38 VK2DX 7.040061 -23 0 QF56oe 0.0001 VK1DSH QF44ms 253 231

Like to get on WSPR with your homebrew rig? Looking for a challenge that goes beyond simple plug-and-play?
Then you should consider the GenesisRadio kit: G3020 is a multimode, 30m+20m duobander with 5W output. Yes, G3020 is no beginners kit but if you are clever and possess good soldering skills you'll get it right too. Homebrewing+QRP=Fun! For more information visit http://www.GenesisRadio.com.au
73 Nick VK2DX

PS here is an unsolicited report from yet another happy builder: