QRPP / QRSS beacon experiments

A summery of my QRSS/QRPP activities

The whole thing started in autumn 2004 when Peter, DL6NL, informed me of the QRSS Knights group, a small number of hams who fiddle with narrow band techniques at mW or even µW power level to investigate short wave propagation or to test their antennas and other equipment. Peter asked me to change the firmware of my CWKtiny unit to make it suitable as a control device for QRSS operation. Weeks later I sent an updated ATMEL processor to him which allowes QRSS operating without having a PC steadily running. At that time I did not really want to take part in 30m QRSS, but with the couple of days and the arriving e-mails from the reflector, it seemed more and more interesting to me ...

I found some interesting QRSS related stuff in internet at

W0CH - What is QRSS
KA7OEI - QRSS and you
QRP-TX mit Epson Oszillator SG8002
G0UPL's 30m Beacon Page
Fuzzy Modes and modern Digital Modes, ZL1BPU

Finally, I subscribed to the e-mail reflector of Johan, ON5EX, to be always informed about current activities of the "QRSS Knights".

After downloading the Spectrun analyzer programs "ARGO" and "Spectrum Labatory" I could receive the first QRSS signals.
In autumn 2004 I decided to built an own beacon transmitter. Since there were no 10,140 MHz available, the idea of mixing two oscillator signals from (unexpensive, easy to get) 4,000 and 6,144 MHz crystals to the sum frequency of 10,144 MHz came into my head. The result was the "heterodyne beacon" shown below.Being able to tune down at least to the 10,140.xxx segment, I decided to make use of 7N3WVM's Super VXO with crystals in parallel. I was afraid of a bad frequency stability because you hardly can tell if the drift of the two XOs will add or compensate. Housing in the entire oscillator section as well as adding a PTC heater (a self-regulating 60C hot ceramic disk, supplied with 12 Volts) should solve the problem. First tests on 12 Oct. 2004 showed not a rock solid but a sufficient frequency stability.

True, not the best solution and not really advicable for reproduction but it allowed a quick start and gaining experience with QRPPing.

G0UPL's Slow Hell transmission as well as the experiments of Vic, G3GKI with various new signal patterns inspired me to add more QRSS features like DFCW, FSKCW, HELL, SLANT ... to the CW keyer's firmware. Most of the graphical modes require an additional D/A converter circuitry, described in the CWKtiny's manual.