Simple 10m DSB transmitter

From Steven, G7VFY comes news of a very simple 10m DSB transmitter from the blog of KA7OEI. This is an experimental very low power transmitter. It is unlikely to be of use in serious applications, but the range might surprise some.  On 10m, the antenna is efficient and on a clear frequency it has the potential to get a long way. Over 1000km would not surprise me on a totally clear frequency. After all, 1mW (or so) is about 53 if a 100W signal was 59+12dB. On 10m such signals with 100W are very possible.

See http://ka7oei.blogspot.co.uk/2014/10/the-pointless-10-meter-dsb-qrp.html .

472kHz

I have been on 472kHz WSPR most of the day using 5mW ERP to the earth-electrode "antenna" both on RX and TX.

On RX DK7FC (669km) continues to put out his very strong signal.  It is no wonder he is regularly copied in the USA.

On TX I am still being copied by G0LRD (25km) and G8LCO (58km).

G3YMN (112km) is a new reporter in the last 24 hours. Thank you for your spots.

UPDATE 2148z:  A new reporter, and new country, copying my 5mW ERP from the earth-electrode "antenna" this evening - Finbar, EI0CF (602km), using his Perseus RX and 120m long Beverage antenna. Report was -27dB S/N at 2218z.

Optical communications - over the horizon (NLOS)

The DX record for communications at optical frequencies is phenomenal these days. There is a growing interest in communications over non line of sight paths (NLOS) using cloud-bounce or clear air scattering. To my knowledge, in recent times experiments are (or are about to start) by F1AVY, VK4EBP , VE7SL and G3XBM (when fit again). I am sure there are others too. Weak signal modes certainly help. I used QRSS3 over an 8.5km NLOS path, but much further has been achieved.
 
See http://en.wikipedia.org/wiki/Non-line-of-sight_propagation .

A couple of useful optical Yahoo groups are:

Australian Optical DX   https://groups.yahoo.com/neo/groups/Optical_DX/info

UK Nanowaves              https://groups.yahoo.com/neo/groups/UKNanowaves/info  

10m WSPR DX

There was 10m DX to be had today. The first USA station to spot my 500mW WSPR signal was WG2Z (5600km) at 1216z. At the moment, the last USA station to spot me was K9AN (6505km).

Also spotting me earlier in the day were ZS6A,  ZS6DX and RI1ANR (13676km) in Antarctica.

UPDATE 2028z:   K9AN (6505km) was the last USA station to spot my 500mW  WSPR beacon today.

UPDATE 2032z:  I have now gone QRT on 10m WSPR. Another decent day on the most interesting of bands.

Sunspots

Sunspot number today is a respectable 156 and 10m propagation is expected to be "good".  So far just Europeans copying my 500mW 10m WSPR beacon.

Last USA spot today of my 500mW on 10m?

At the current time, 1910z,  WA0APC (7012km) was the last to spot my 500mW WSPR on 10m at 1650z. Since then, just Europeans spotting me. It is still just about possible that other USA stations might copy me, although it has been dark here now for 3 hours, so I'd be surprised.

The reports from Germany were very strong, so possibly this was winter Es?

UPDATE 2046z:  K9AN (6505km) was the last USA station to spot me on 10m today at 1828z. The last international spots of me on 10m were DK0UG (+1dB S/N) and DK0SC (-11dB S/N) at 1912z. Since then,  just local G4IKZ (18km) spotting my 500mW on 10m WSPR.

UPDATE 2230z: Went QRT on 10m WSPR.

472kHz WSPR

All day I have been on 472kHz WSPR and on 10m WSPR since mid-morning. Since mid-afternoon G8LCO (58km) has spotted my 5mW ERP several time. Last night at 0220z I was spotted by F1AFJ (607km). I think this is the second furthermost report of my 5mW ERP with the earth-electrode "antenna".  At some point I really must work out how many unique 472kHz WSPR spots I have had at this QTH. My best DX is over 1000km when I was spotted in Norway.

Antarctica yet again and, of course, the USA

At 1216z I see that my 500mW 10m WSPR beacon was spotted in the Russian base in Antarctica again by RI1ANR (13676km) at -21dB S/N.

My first spot from the USA today was KE6BID (5295km) at 1220z.

UPDATE 1406z: RI1ANR has spotted me 8 times already today so far. From here, the Russian base is almost due south.

UPDATE 1506z:  Propagation on 10m to Antarctica seems to have closed (or RI1ANR is in bed!) as no further spots received in the last 1 hour. He is still shown as being active according to WSPRnet.

UPDATE 1536z:   Plenty of reports again of my little 500mW 10m WSPR beacon today so far.

Unique 10m WSPR spots today so far - 500mW

UPDATE 1656z:    AB4QS (7087km) is currently the best DX in North America. Clearly, the Russian Antarctic base is much further.

Direct conversion ICs - CMX994

Since my days in mobile radio (now nearly 7 years ago) things have moved on.   CML now sell a VHF/UHF direct conversion IC covering 50-940MHz. See http://www.cmlmicro.com/Products/CMX_994_RF_Direct_Conversion_Receiver/?gclid=COrc7qiJ0sICFdLItAodLxEAuA . I wonder if any enterprising radio amateurs have used these yet? I have a feeling the package (ideal for SMA but not for home use) may inhibit its use in amateur projects?

http://www.cmlmi use) cro.com/api/i.aspx?CMX994Promotion.png;529;198

W5OLF website

W5OLF's tiny WSPR-AXE-CW

Jay, W5OLF, the creator of the "no PC needed" WSPR-AXE-CW beacons for WSPR on 30m, 20m or 10m has just started a new website.  He expects to start selling the new versions of his little beacons, either as kits or built and tested units, in late January. These stay on all the time (the PA can be turned iff) , but frequency is randomised over 100Hz within the WSPR window. Once set, the timing is fine for ages and ages - certainly days or even weeks.

Jay's email (replace the (at) with @ ) is: w5olf(at)comcast.net .

His new website is www.w5olf.com .

I am privileged to be a beta tester of his 10m version (500mW). As you will have read in earlier posts, this unit certainly works very well, mine having been copied all over the planet in just a few weeks. Just press a button to sync time on an even minute and watch all the reports come flooding in. I was blown away with mine. Tiny, but brilliant. If you like WSPR I can thoroughly recommend this little unit. It comes pre-programmed with callsign, locator and power level.

UPDATE 1448z: This little unit has been spotted in Antarctica (13676km) 8 times today already. My antenna is nothing special, just a low 3 band end-fed wire.