This project came into being when Jan G0BBL kindly gave me one of his SRR-Kits USB Si570 synthesiser modules. I added a junkbox IRF740 MOSFET PA, Low Pass filter and ATtiny13 AVR keyer and put it on air on 30m QRSS for some reports! I used a 30m dipole: 7.1m long on each arm and with a balun at the centre consisting of 6 bifilar turns on a T37-43 toroid, driven by a length of RG58 coax direct from the PA (no ATU). Read here for how to construct a similar balun. The dipole is 2 stories up the building but is close to the building, well shielded by metalwork for several metres of one end, and also well shielded by surrounding high buildings... so it was a real pleasure to see my signal getting out so well.

Transmission details:

After running the beacon for 5 days I'd received a good number of reports from Europe and North American and switched off the beacon. I concluded that the Si570 module is extremely stable. The programmed frequency was about 30Hz higher than the actual frequency. The thermal stability was excellent, no measurable drift at all was evident during the 5 days. One disadvantage of using this Si570 module as an FSK source for a QRSS beacon in this mode is that it requires that the USB host (an old 333MHz Pentium II PC in this case) must be switched on 24 x 7 to provide the FSK.

	Construction: Construction details are presented here. All other components than the Si570 module i.e. PA, Low Pass filter etc were from the junk box. READ MORE.
	Reports: During 5 days of operation 24 x 7 a good number of reports were received from stations in Europe and North America. On this page I've included a representative sample of some of the best reports. READ MORE.
	30m QRSS Receiver: Don't miss this related project: a simple 2-chip 30m QRSS crystal controlled direct conversion receiver powered with +5V from a computer's USB port! READ MORE.

List of receiving stations

Currently reports have been received from 9 stations as follows:

QRSS WEBSITES