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Tuesday 14 July 2009

Troposcatter Experiment - Conclusion

I carried further hilltop listening experiments yesterday evening, paying attention to troposcatter at different moorland locations in Derbyshire, using the Sony XDR-F1HD and a Triax FM5, mounted horizontally at 15ft agl. (This was Band 2 FM reception) 

Yesterday evening, I compared Middleton Top with Bonsall Moor, driving quickly between the two locations to make comparisons. Both locations are close to Matlock in Derbyshire and are neighbouring hills, separated by only only a few miles. The Bonsall Moor location is approximately 150 feet higher asl than Middleton Top. (Recent trips have also included Alport Heights, Eyam Moor, Taddington Moor and Beeley Moor) 


2m HB9CV at Bonsall Moor

As is already known, Middleton Top offers a good take-off from all points east through south-west and is surrounded by higher hills which run from the NW through to the NE. These provide a good blocking effect to semi-local stations from the north. The same shielding does not exist at Bonsall Moor, which only has useful blocking to the west where the summit rises to 1250ft asl, so I did not expect to experience almost identical reception at this more-exposed location, yet these two local high spots bore many similarities. A good example would be Hallam FM on 103.4 to the north-east which was very low in strength at both locations, thus allowing excellent reception of Heart Milton Keynes 103.3 - particularly at Bonsall Moor. Local Trent FM 96.5 and Mansfield 103.2 were also weaker than expected. Reception of BBC R Cambridgeshire 95.7 was perfect, as was Norfolk 94.4. I was even able to null local pest BBC R Nottingham on 95.5 at Bonsall Moor, though nothing else was heard due to conditions being flat. 

Troposcatter next: Middleton Top had several French transmitters coming through, including Troyes 91.4 and Bourges 91.8. Only two German stations were noted at Middleton Top: HR3 Sackpfeife 87.6 and SR1 Gottelborner Hohe 88.0. While at Bonsall Moor, Troyes and Bourges were much weaker and many more German transmitters were audible, including Bremen, Aurich, Nordhelle, Langenberg, Aachen, Koblenz, Bonn and Munster. London pirates are also more abundant on Bonsall Moor, so this makes a good all-round location for band 2 FM DX. 

There are two reasons for my recent trips: 1. To determine how high I need to be in order to experience good troposcatter reception; 2. To find a location closer to home which equals the Axe Edge for troposcatter reception. So far, nothing has equalled the Axe Edge for its reliable troposcatter reception of French, Dutch and German transmitters. London pirates are better received at the Axe Edge too. Maybe the reason is the height of the Axe Edge receiving location at approximately 1700ft asl. The higher parts of the Axe Edge also provide useful blocking effects to some of the nearer transmitters too while favouring reception from north-east to south. 

All locations I have tried recently have equally good take-offs to the east through south yet the Axe Edge is the clear winner when it comes to superior continental troposcatter reception. Interestingly, my home location also has an unobstructed 'view' to the east, highlighted by good, daily reception of stations in the east and south-east of England, yet I struggle to hear troposcatter reception of the kind experienced in Derbyshire. The extra height asl of the Derbyshire hills clearly makes the difference. 

Good DX! 

John 

Friday 10 July 2009

Eyam Moor DX Trip


Looking east to Grindleford from Sir William Hill

I drove to Eyam Moor yesterday afternoon and set up a Triax FM5 close to the summit of Sir William Hill (1407ft asl) for a spot of broadcast FM DXing. I was hoping the summit might have provided more in the way of shielding to the SW-W-NW-N but many stations still got over the hill with very strong signals thus blocking many frequencies. Winds were strong so I could only get the mast up to 12 feet agl. 

All stations below were weak and very choppy, typical of troposcatter but all peaked to noise free levels at times. 

  87.6 HR3, Sackpfeife
  87.6 NDR2, Hamburg
  87.9 NDR Info, Heide
  88.0 SR1, Gottelborner Hohe
  88.0 WDR5, Bonn
  88.0 NOS2, Smilde
  88.7 France Musique, Lille
  89.2 France Musique, Reims
  89.4 France Musique, Boulogne
  92.8 RTBF Musiq'3, Profondeville
  93.8 Bremen Eins, Bremen
  94.0 SWR2, Koblenz
  94.0 France Culture, Rouen
  98.0 France Culture, Lille
  98.1 WDR3, Nordhelle
  98.1 NDR2, Aurich
  99.1 RTBF Classic 21, Anderlues
  99.2 WDR2, Langenberg
  99.2 NDR Kultur, Hamburg
100.0 WDR4, Munster
100.4 WDR2, Bonn
100.8 Bremen Vier, Bremerhaven
100.8 WDR2, Aachen 

Equipment used: Sony XDR-F1HD & Triax FM5 at aproximately 12ft agl. 

Some more photos of the countryside around Eyam Moor: 





Tuesday 7 July 2009

6m Aerial Debate On Skywaves

Over the last few days I have been wondering if my simple 3 element 6m beam is up to scratch for working the more exotic, distant DX. My curiosity had me posting to the QRZ and Skwyaves forums for feedback. Unfortunately, my request for help on the Skywaves forum developed into a heated debate, followed by arguments in which I admit I became rather 'verbal'. Those who know me appreciate the fact that I speak my mind. I try to do it tactfully. If you feel strongly about something then you are sometimes willing to go a step further and sate your feelings in no uncertain terms. I admit, I can be an argumentative sod at times and this does not do me any favours, but why? People should be honest.

So what was it all about? Well, like many amateurs and radio enthusiasts, I am restricted for space at my QTH and I could only consider a simple three element beam for my first season on 6m and, as we know, 6m aerials are on the large side. I have a small garden and there are already various other aerials on my roof on rotators and on the garden. I did not wish to further annoy the neighbours by erecting yet another 'eyesore'. There is, however, a more important reason why I opted for such a simple aerial: I would have less chance of missing exotic DX if it came in on the side or back of the beam> Too much directivity can work against you. 

The telescopic mast arrangment on the garden allows my rather heavy Sandpiper 6m beam to rise to 20ft above the ground before any major swaying develops. Any taller and I would need to use guy ropes - something I wanted to avoid. So, before we get to the arguments, I accept that I have a very simple setup for 6m, but one which has proved to be more than capable of working European E skip at good signal levels during the summer months. 

Already this season, I have worked stations as far as the Canary Islands and Turkey, with my 100W signal often breaking through heavy pile-ups. I have had many QSOs with the majority of European countries, yet I have so far failed to work transatlantic DX, despite having heard heard stations from the USA, Canada, Puerto Rico and the Dominican Republic. These have been heard up to S5 signal strength at times. Theoretically, if I can hear somebody, they should be able to hear me, however, it is never that simple due to a number of reasons: Stations using differing transmitter powers; Differing aerial systems; Pile-ups and QRM at the distant end, etc. The so-called "big guns" may indeed have a better chance of working exotic DX over somebody such as myself with a relatively simple beam which is not even above the height of the rooftops. But as most of the DX world will confirm, there is always a degree of chance in these situations and 'being in the right place at the right time' counts for a lot. 

If an 'exotic DX' station is active, the whole world comes out of the woodwork. This presents another drawback: I suddenly find myself in the middle of a vast sea of stations, all calling simultaneously in an attempt to be heard, thus further reducing my own chances. It's also probable that most of those stations will be suffering the same congestion, but throw in QSB and DX windows begin to open. Even the 'big guns' will fade and it could be that my signal will peak at that moment. This can create a balance and give all stations an equal playing field. Suddenly you realise that all things might just be possible.

Still there is a lack of TA (transatlantic) here. I seem to be hearing fewer TA stations than some others, but this could simply be because of conditions not favouring my location. Maybe I have been in the wrong place or at the wrong time. But my lack of TA success got me thinking: 

I began to wonder if my close proximity to the hills of the Peak District was blocking TA signals. I looked at the angles involved. The land starts to rise from approximately seven or eight miles to my west and quickly rises to more than 1200ft asl. Add a few more miles and the land approaches 2000 feet. So if my aerial is to 'see' above the nearer parts of the Peak District, it needs to be angled about half a degree skyward. Such a small angle is not even worth considering, so maybe the Peak District might not be so close as to cause a blocking effect. 

Next, I needed to look at whether 6m TA reception is received via a low angled single duct of E layer propagation or if it comes via high angled multiple hops, thus changing the angle of arrival. If the angle is high then I would need to point my beam more towards the sky. There has been some debate about this. As you will see, my concern now was that, if a single hop 'duct' was the only way of working 6m TA, the angle of arrival might actually be lower than my nearby horizon, so maybe the Peak District could be the problem. Time to get a few opinions. 

Firstly, I wrote to QRZ.com, expecting to be shot down in flames because of my simple aerial setup. Some radio amateurs adopt a very elitist attitude. Instead, I was pleasantly surprised. The replies I got were very helpful indeed and a number of relevant issues were politely discussed. However, my post to Skywaves was met with a completely different response, largely from a particular Australian member. What rather annoyed me with a couple of the replies was that my 6m 3 element beam was simply not good enough and that I should not expect to work exotic DX of any kind. I was a little perturbed (to put it mildly) by the strength of one response in particular and found it unreasonable that the relevant facts were stated in such a 'black and white' nature. The opinions seemed to rule out all elements of chance too. The big problem for me was that such blunt attitudes were of no help to newcomers to the DX hobby. One reply offered no encouragement at all and that the comments were totally dismissive. (Anger now building) I am not prepared to allow somebody to dictate to me what I can and cannot receive, especially when they were on the opposite side of the globe. Thankfully, the majority of the replies included common sense and favoured the elements of chance, but regretably, these supportive messages were received 'off-group'. Some members of the Skywaves forum actually telephoned me to express their anger at the dismissiveness of the poster. 

Further negative posts were made to the Skywaves forum by two other radio amateurs, one of whom had just joined and was stating that none of the DXers in Skywaves were 'real DXers' because of the inferior equipment they used. War practically broke out (and, yes, I know I was one of those hurling the missiles, but I find it difficult to keep quiet when innocent people are getting hurt). The Skywaves moderators had to intervene to calm things down. 

I get very angry when people take a 'holier than thou' attitude and make sweeping statements, dissmissing those whom they feel are beneath them. This is a competitive hobby for some though. I know that some DXers and radio amateurs get very upset if they have miss out on exotic DX. Perhaps it is understandable to a degree if they have invested large amounts of time and money to improve their setup, so it must be soul destroying for those elite DXers with their lattice towers and stacked arrays when they discover that a DXer down the road with nothing more than a bucket and a piece of wet string has been pulling in far more than they have. That's life! Conditions are a natural phenomena over which we have no control, so these things will happen, but is it worth losing sleep over and me writing an essay about it? Of course not, but I wanted to reflect over this and offer some balance now things have calmed down. DXers and radio amateurs frequently achieve something that they thought to be impossible when using relatively simple aerial systems. I am not aware of any law which states that one "can" or "cannot receive X just because your aerial is not good enough", as two of the Skywaves members were stating. A law entitled "Being in the right place at the right time" would make far more sense. 

Time and time again, history has shown that, while we all have our different receivers and aerials, they often have no bearing on the DX we actually receive. Conditions will change and DXers will indeed find that they are 'in the right place and at the right time'. I fully accept that superior setups offer advantages, they do not govern the laws of propagation. Much stunning DX has been worked or received over the years on very simple equipment. We even have groups for those interested in 'QRP' or 'Ultralight' which present more challenges to the DXer. Many of these people go on to achieve 'as much as' and sometimes 'more' than DXers with relatively superiior equipment. It could also be because of the skill of the operator and their dogged determination, plus a little bit of 'luck'. 

I believe I 'will' work TA DX on 6m, but I also accept I may need more luck than some and I need to be on my guard to achieve my goal. 

UPDATE:
Well, it happened! On the 31st of May 2010 I worked a 6m station in the US Virgin Islands and two stations in Puerto Rico. These are my first two transatlantic DX QSOs on 6m. Surprisingly, the QSOs were relatively easy. I simply responded to their calls and 5/5 to 5/9 signal reports were exchanged, so there wasn't even a struggle! 


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