22 Aug 2009

Sporadic-E ....is it getting better year on year?

Since the 1960s I've enjoyed hearing and working DX via sporadic-E openings in the summer months. For me, it all started with DXTV reception on Band 1, much to the annoyance of my parents when I retuned the TV trying to find weak Italian and Spanish TV stations.

But have sporadic-E openings changed and become far more intense in recent years? Looking at the reports of summer 6m DX now and you will see DX as far as S.America, The Congo, Japan and Texas to name but a few. Now is this because there are more stations, DX clusters and the like or is the E layer now doing things it wasn't doing (at least not as often) 40 years or more ago? Indeed, are these super so-called multi-hop Es openings really sporadic-E as we understand it? Or is the E layer now more intensely ionised more often?

Incidentally, with WSPR I seem to find 10m open to Europe almost all the time, day and night.

SSTV

Never tried SSTV before so I used Digital Master 780 (comes with Ham Radio Deluxe) to receive on 20m today. Several pictures came through including this one from JN1VNW, the first I decoded.

19 Aug 2009

2013 for sunspot cycle 24 peak?

A new sunspot prediction from Australia is showing we haven't reached the minimum yet and the new peak won't now be until 2013! If correct we have to get used to conditions remaining poor on 10m F2 for some time yet. See http://www.ips.gov.au/Solar/1/6

17 Aug 2009

Afghanistan on 10m

Overnight I left my 10m WSPR station running 10% TX at 5W. During the night I was spotted a few times by a couple of Europeans. My best reception was of T61AA in Afghanistan from just after 0600z. Unfortunately he was unable to copy my 5W on 10m.

This is the WSPR chat log showing that T61AA was genuine. He has been trying EME and 6m at other times today.

16 Aug 2009

Getting back to homebrew QRP

For the last 10 days I have been "distracted" (by my discovery of WSPR) from my main interest - building simple homebrew QRP gear. In the next few days I hope to have rectified this lapse and got busy in the back of the garage making something new. Not sure what yet but I feel the urge to build again.....

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!