May 17, 2018

6m Sporadic E and the Maldives on 20m (WSPR chatter 5)

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It's May and that means that the Sporadic E (Es) season is upon us. I've always been fascinated by this unusual radio propagation phenomenon, and I have fond memories for instance of the 1990s when I did a lot of VHF band I TV DXing, with Es during spring and summer enabling me to catch TV stations from all over Europe and sometimes even beyond.

For this Es season I had planned to do some 6m WSPRing with my QRP Labs U3S. So recently I quickly built the U3S 6m LPF kit that had been lying around for some time, and I also made a simple 6m dipole. And with simple I mean really simple; just some wire cut to resonance, some pvc pipe insulators, and lots of hot glue. The antenna is placed indoors in the attic.

The centre insulator of the simple indoor dipole made for 6m WSPR

With my U3S on the HF bands frequency drift never had been a real issue (mostly 0 on the lower bands, and mostly 0 to 1 or an occasional 2 Hz on the 20m band), but now on 6m the drift was considerable, mostly 4 Hz, probably making decodes impossible or difficult. But setting the "park mode frequency" to mode 2 and 150 MHz (to keep the U3S' DDS warm in between transmissions) cured the problem and reduced the drift down to 0 to 1 Hz.

The power of the U3S on 6m is less than on HF; on the "Magic band" I measured it puts out less than a 100 mW.

Es conditions so far haven't been great, and I've also noticed that there isn't really much of a "WSPR scene" on 6m  (which I find very strange, as 6m is really interesting to do WSPRing on to study the unusual and fascinating propagation phenomena of this band). Nevertheless, a couple of days ago my tiny 6m Es WSPR signals were spotted for the first time thanks to SV2HNH in Greece. On HF it wouldn't be that special, but now I was really excited about it.

SV2HNH hearing PA7MDJ on 6m

I will be WSPRing on 6m this Es season on and off. There's a very active monitoring station in Morocco (CN8LI), and for the remainder of the season I've set my goal to having my WSPR signals picked up by this station at least once.

Further exciting news is that my 200 mW WSPR signals were picked up on 20m by 8Q7HI on the Maldives, my 69th DXCC reached with 200 mW WSPR (see my WSPR DXCC list here). TX was my U3S, and the antenna used was a HyEndFed 10/20/40.

8Q7HI hearing PA7MDJ on 20m

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  1. 8Q7HI heb ik 2 weken geleden al gespot op 17m maar ik dacht dat het weer zo een TX only baken was. Nu jij bent gespot op 20m ben ik maar direct weer terug gekeerd. Hoop dat ik morgen ook nog gespot word?? Zal de activity lijst nog eens bij langsgaan of hij nog luisterd. TV DX ook gedaan in de begin 90er jaren. Moet nog ergens foto's hebben.....maar waar... ZO een U3S is leuk echter het is TX only en dat is dan weer jammer. Succes! 73, Bas

    1. Ik zag dat het nog gelukt is met de Malediven, Bas, gefelicteerd! Ik heb ook nog een album vol met TV DX foto's. Ik neem er zo nu en dan nog graag een kijkje in. Leuke herinneringen; spiegelreflex camera op een statief voor de TV set en dan met een draadontspanner foto's nemen met een lange sluitertijd. Het mooie was vaak dat door de lange sluitertijden op de foto's vaak meer detail te zien was dan op het moment van ontvangst zelf. Mooie tijden die niet meer terugkomen.