Now That's What I Call A Tropo Opening (Number 115)!!

Hot on the heels of the Es opening, along came a Tropo one.

With the UK experiencing a long hot dry spell, another high pressure system arrived from the Atlantic to cause more scorched grass at GM4FVM.

As predicted in the last posting, where I reported DX in the shape of hearing Belfast Coastguard again, even more DX came along with the first reporting here of Holyhead Coastguard in Wales. Ah, a new ... well ... whatever you call VHF marine band DX. And for a time the entire VHF marine band was filled with Danish and Norwegian coast stations which are a bit harder for me to identify.

Amateur radio was also the beneficiary of all this enhanced propagation. Things had hardly begun when the RSGB UKAC 432MHz contest took place on 9 August. Conditions were a bit better than normal but my time at the microphone was limited and I worked only six stations. Maybe only six, but they were stronger than usual.

Dick, GM4PPT in IO75 asked "where have you been?", the answer to which should have been "hiding behind the Southern Uplands range of hills". The path between here and PPT is very tricky even though it is only 153km. My log, which is not very accurate when it comes to contests, suggests that it is eight years since I worked Dick, and it takes a lift to make it possible on 70cms. 

Contest ODX was as GI6ATZ in IO74 at 296km. Notable was a strong signal from GM4TOE in IO87 at 200km. Although I regularly work Barry on 1296MHz, this appears to be the first time I have ever worked him on 70cm. So things were a bit better on the evening of 9 August and everything in the pressure charts pointed to the next few days being open to possibilities.

By 10 August the 144MHz band as seen on PSK Reporter was beginning to look more like 80m:-

144MHz as seen on PSK Reporter at 20:38 on 10 August 2022

Over the four day period of the lift the bands opened in different directions on each day. For this purpose though I am looking at the whole period as one opening.

144MHz contacts at GM4FVM 10 to 14 August 2022

This is a pretty presentable set of results - 28 QSOs in 18 squares. 8 DXCC on 2m in four days is not shabby. The ODX of SM6BUN at 1028km in JO78 is good. Perhaps because I am getting used to fantastic results then just very good ones do not excite me as much. Let me just say that these days if I do not work SP or OM in an opening like this I feel a bit let down. That is crazy of course. This opening was characterised by lots of contacts over four days, other ones have fewer contacts and shorter durations, but they have better ODX. You cannot win them all, though I would like to.

Perhaps the results on 2m were influenced by the fact that I was concentrating on 70cms.

432MHz contacts at GM4FVM 10 to 14 August 2022

I spent more time on the 70cm band, and the result is that the map looks very like the 2m one. The openings covered the period of the "Euro FT8 contest" on 70cm as well as the RSGB UKAC 70cm FT8 contest too. That helped, but most QSOs were outside the contest. The contest certainly increased the QSO numbers to 59, as several stations worked me a second time during the Euro contest (and one three times to include the RSGB Contest too). Then there were several QSOs with G0BIX testing various things which brought up the totals again.

As is often the case during a tropo opening, ducts formed. Sometimes these can be long lasting, and sometimes very short lived indeed. The ducts create very strong signals in both directions but they are usually limited to small areas at each end of the path.

As an example of a powerful short lived duct here is a screenshot of my contact with PA3FWV on 11 August. I called CQ, and after the first call PA3FWV came back to me. We exchanged reports at +19 and +23dB.

 

 

Contact between GM4FVM and PA3FWV on 11 August 2022

I had heard nothing from PA3FWV before calling CQ. I have heard nothing from him since. I only heard him during three 15 second transmissions which were all during that one QSO at +19, +20 and +20. I have never heard him during any other lift. He had never heard me before. This was his first GM contact on 70cms. So this duct made possible a contact at very considerable strength between two stations who have no history of being able to work on 70cms, even during previous routine tropo lifts. 

I had not worked a station for 15 minutes before the contact with PA3FWV - that was SM6VTZ - and I did not work another one for 15 minutes afterwards - that was PA9R which gave me a -19dB report. The contact with PA3FWV stood out as a real indicator of the power of a tropo duct. It was completely out of character with the rest of the opening, as ducts so often are.

It would not be a tropo lift for me these days if it did not involve 23cm.

1296MHz contacts at GM4FVM 10 to 14 August 2022

Six QSOs, five squares, three DXCC, and an ODX to OZ2ND in JO46 or 690km. OZ1FF chipped in with a not inconsiderable 612km. You might think that is pedestrian but I loved it. I always say that raising operations to a higher band doubles the points for each QSO. And "points mean PRIZES" (whatever that means).

As so often on 23cm, OZ2ND and F5APQ are my targets. 690 and 605km on 23cm are quite respectable distances. Of course, when I started on 1296MHz I never expected to get anywhere near that far.

The path to Niels Erik is pretty straight forward - across the North Sea.

Path to OZ2ND from GM4FVM

On the other hand, reaching Jacques, F5APQ, is a lot more difficult

Path to F5APQ from GM4FVM

As usual you can click on any of the images to enlarge if you need to.

To get to F5APQ my signal has to pass over the headland near me, over the Northumberland Hills, across a stretch of sea past Sunderland, then over high peaks via the North York Moors, over the Humber Estuary, then over hills separated by The Wash, finally crossing the English Channel to France. This is a far more complex route than crossing the North Sea but not so far either. Or maybe the path to Jacques is just as long because it is indirect (see paragraphs below)

So working these two station make up two different challenges. The longer distance to Niels Erik is the easier to do, and I work him more often. Working Jacques is quite a task and although it happens less often it is just as pleasing when I can do it. While the hills to F5APQ are all under 400m, the route is bumpy and more obstructed than the flatness of the North Sea. Both tasks have their own issues and I enjoy hearing either station. To work both is a real pleasure.

Another anomaly which affected both 70cm and 23cm is that several station reported was that beam headings were not what we would usually expect. This may explain how it is possible for me to work F5APQ despite the difficult terrain. G0BIX on 70cm, G4ODA on 23cm and F5APQ (both bands) reported getting the strongest signals when beaming further East than expected i.e. towards the North Sea. This was at times when fog and Haar were being seen over the North Sea at GM4FVM, and strong Continental marine stations being received on VHF. 

Clearly it is possible at times to avoid the hilly overland paths (such as the one to F5APQ?) and find a longer but stronger path (reflection or duct or some other scatter mechanism?) by beaming towards a high pressure system off the main path. I knew this might be a factor on 23cm but I never expected it to work on 70cm. I need to learn more about this and try it more often.

The trick, it seems, may be not to beam towards a station when I hear it. My natural tendency is to assume that the direct path will be the strongest. I have had to learn that this is not necessarily the case with meteor scatter, and maybe not during tropo lifts either. 

And then it was over. Atmospheric pressure at GM4FVM started to fall. Rain fell to the benefit of the fruit and vegetables in the garden and to the detriment of radio conditions. Everything returned to normal. If it was not for normal I would never appreciate a lift.

The balance of activity I get by running both low VHF (50 and 70MHz) for Sporadic E etc. and high VHF, UHF and low SHF (2m, 70cm and 23cm) for tropo etc., means that there is often something happening. If you throw in my occasional EME activity then I usually have something to do, or something is about to happen.

This year I have hardly been present during the Perseids meteor shower. I have had a few contacts on 70MHz, particularly to Mek LA/SP7VC, but more on Mek in a later post. I even briefly ventured onto 2m meteor scatter when I heard DH8BQA. In general though I have been busy elsewhere.

That is it for now. Tropo followed Es. Time for aurora to follow Tropo? Or maybe an F layer opening to Australia on 6m?

73 Jim GM4FVM