Wednesday, 25 September 2013

2m - a Band of Two Parts

Like the incoming tide washing away a beautifully constructed and elegant sandcastle, bit by bit, this week’s tropospheric ducting crumbled away with equal inevitability.

At its height, this radio superhighway, formed by different layers of air density and temperature, ‘hotwired’ parts of Europe together on 2m and above like they were connected with RG45 coax itself.

The opening was heralded, accurately, by William Hepburn’s tropospheric ducting forecast (see http://www.dxinfocentre.com/). This site also explains various propagation modes on VHF and above, in a clear and informative manner.

Let me tell you a little about my 2m station here in North Wales. I have a lovely Icom IC-910HX and my antenna is an HB9CV. Yes, you heard right, a peashooter. Two small elements phased together and put up on a pole on the side of the house. You see, I’m starting modestly because our national culture demands that we never do things the easy way. Added to the equation of difficulty, I have a range of 3000ft mountains not too far away from me. Did I mention the HB9CV was fixed? It points plaintively towards the south-east in cold, metallic expectation of flux. It points towards the long, golden beaches of the low countries, the rolling fields of northern France, the great cities of Western Europe and finally, the snow-capped Alps and beyond. But it also has a ‘heart’, a cardiod footprint in fact. The characteristics of the HB9CV trade-off a modest gain with quite a wide beam-width, with a sharp null behind it, giving it its heart shape.

The humble HB9'
You need good hearing. The receive gain is lacking for weak-signal work, but work it does. And this week I worked a station (OE2XRM) in Salzburg, Austria. 5,5 both ways! The pure magic of hearing a man who may be wearing lederhosen over what is normally a line-of-sight form of communication, is thrilling! A couple of stations from Bavaria followed and I was then content to listen as the chatter of stations from France and the Netherlands filled the band.

Later in the afternoon, fuelled by electromagnetic excitement, I ventured onto a local hill (178m/584ft.) with my lovely FT-817 and a 9-element 2m yagi. I also took along a 70cm yagi for fun.

A quick scan through the beacons bought in HB9HB in Switzerland! The Alps, the chocolate and cuckoo clocks! Unleashing my 5W on Europe didn’t produce much, unfortunately – just a couple of cheery calls from the UK, so I thought I’d swing the beam round to Spain. Now, the DX cluster was not showing any propagation in this direction and I wasn’t hearing any of the beacons on the north Spanish coast. But suddenly, out of nowhere, and at 5,9+, came a signal booming in. Danny, EB1LA, on the northern Spanish coast was stunned to hear me at 5,9 with my humble five Watts. What a result! I can only conclude that the beacons may have been situated too high to ‘tap in’ to the duct. How many people in the UK and Ireland must have been beaming away from Spain that day having assumed that no beacon = no path? I wonder. A quick scan on 70cm revealed no traffic, but I did receive the Netherlands beacon PI7CIS. Quite a trip for UHF.

My hilltop station
The two metre band can be sublime, but comes in two parts. The FM part of it is like an amateur ‘pub’. It seems the place where people gather in the evening to discuss their day and engage in chat (For example, one QSO I heard earlier this year was despairingly on the subject of “my favourite biscuits”). But the lower portion of the band has the elegance and sophistication of a Grand Cru. It’s as if it’s optimised in terms of antenna size, required power and number of users to give you a fighting chance of achieving glory in the aether. And I did.

Postscript 03 Oct. 2013: Just read EI3KD's excellent blog about this tropo opening. It coincidentally contains an audio capture of the end of my QSO with OE2XRM! Recommended reading (and listening).

6 comments:

  1. Great contacts Rob and a great read!

    73, Tim G4VXE

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    1. Thanks Tim - not blogged for a while! 73.

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  2. Very eloquent Robert, nice piece.
    Rich gd3yeo

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    1. Thanks Rich - I'll have a 9 el up in the next few weeks. Speak soon!

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  3. Replies
    1. Thanks Graeme. Glad you enjoyed!

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