16 Aug 2009

50MHz aircraft scatter

Interesting piece on G3ZJO's blog about 50MHz aircraft scatter using WSPR signals. He has a nice waterfall display showing the strange things that happen to a WSPR signal when aircraft are moving.

WSPR versus CW - what's the improvement?

As WSPR is so effective I asked Joe, K1JT, what the difference is between WSPR and "ear-and-brain" CW. This is his very helpful reply:
"For an answer to your question about relative sensitivities of CW, WSPR, and some of the other modes implemented in WSJT, let me suggest going to the "References" link on the WSJT web site, http://physics.princeton.edu/pulsar/K1JT/refs.html ,
and select reference #11. Table 3 on page 9 gives the information you asked about. The difference given there is about 11 dB, in favor of WSPR over ear-and-brain CW. For most operators, the difference is more like 15 dB."


15 Aug 2009

OK1IAK's tiny WSPR beacon TX

Vojtech OK1IAK has created a tiny WSPR beacon TX based on the KD1JV Altoids tin ATS-3b transceiver kit. He uses the ATS3bv-1.5 firmware. For those not familiar with this creation, it is a tiny 6 band CW/digital transceiver kit fitting into an Altoids tin. See OK1IAK's alternate firmware for WSPR with this rig.

14 Aug 2009

Heard in VK on 40m QRP again

At 1834z, 30 mins earlier than last night, VK8CH reported my 5W WSPR signal at SNR -27dB, which is 1dB lower than last night. A few hours later, VK8CH copied my 2W (33dBm) 40m WSPR signal at SNR of -24, -27 and -28dB over a period of some 20 minutes. PY2GN has heard me twice tonight already on 30m WSPR, again using 5W. W1XP was copying my 1W 30m WSPR signal at a SNR of-17dB.

All this on 15m of end-fed wire strung from the gutter to the washing line post at the bottom of the garden!

13 Aug 2009

40m QRP WSPR signal copied by VK8CH

This evening, VK8CH (Australia) copied both my 10W, then 5W QRP 40m WSPR signals. DX was 13800kms - not bad for a small, 15m long, end-fed wire strung down the garden only 6m at the highest end and 2.5m high at the far end!

What constitutes a QSO?

Having been experimenting with WSPR beaconing, and having a LOT of fun too, I started to ask what constitutes a QSO?

For example, this evening on 160m I both sent and received callsigns, locator grids, frequencies, power, date, time and reports with G8IHT and G4BOO using WSPR. You KNOW the other station has received it from the on-line WSPR database. This was in WSPR MEPT (beaconing) mode and not using WSPR QSO mode, which I've yet to try.

Now, is this a QSO formally? My feeling is no, yet all details were exchanged and received by both parties. Certainly as much detail as would be exchanged in an EME or MS QSO using modes like JT6M, although no RRRs were sent.

Views please?

12 Aug 2009

6m WSPR testing overnight (Aug 12/13)

Overnight I'll be repeating my WSPR mode MS/Es testing, this time with transmissions on 50MHz running 5W for 20% of the time from around 2100z to 0800z. If you have WSPR software, please set your RX to 50.2930 USB and let it run through the night to see what propagation exists.

UPDATE: Not a single report received or obtained for anyone else on 6m overnight. Then 4 hours later I realised I been plugged into the 10m halo :-(

10m WSPR QRP DX - Perseids MS?

I ran WSPR with 5W out (20%) on 10m overnight and was heard twice by F4VNS in JN36hc (see report screen). Although I did not decode anyone on 10m overnight, this may be because there were few stations active on 10m WSPR. The few whispy traces seen suggest doppler shifting (possible MS)?

Anyone know when the Perseids peaked in Europe? I wonder if between 0230 and 0430z?

11 Aug 2009

JT6m Perseids MS

Just turned on the FT817 and JT6M mode and copied HB9AGE within the first few seconds on a strong meteor burst. There will be plenty more tonight. The picture shows the capture of HB9AGE's CQ call here a few minutes ago. Also heard M0RJV, G4BAO (local) and PA5JS, all on JT6m.

10/6m WSPR

During the next 24 hours I intend to try WSPR mode beaconing on both 10m and 6m to see if I get any success during the peak of the Perseids meteor shower. I've no idea how this mode will work with MS and a basic QRP system with small antennas. Should you get a chance, do set your WSPR system to listen on 10m and 6m and log any reports to the WSPRnet logging site. Set your RX to 28.1246 MHz USB or 50.2930 MHz USB to receive WSPR signals.

Although probably not by MS propagation, my 10m WSPR signal was copied by S51CN tonight at 5w, 1W and then 50mW. At my lowest power setting the SNR was -22dB, suggesting that even 10mW would have been copied, but I've now run out of attenuators so can't get any lower tonight!

Bojan, S51CN kindly sent me a screenshot of my signals in Slovenia (see left).