Sunday 16 August 2015

Hunting for VHF DX.

This is what I said yesterday ...
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Here, wait a minute. There has just been an aurora warning. K=7. 
I must have another listen.
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There was no aurora here, or not yet anyway. I am on alert for the rest of today though.

However, I believe that high K levels often are associated with Sporadic E, so last night I went on the hunt. No bed until 2.00am clock time.

After 17:00 6m was buzzing with WSPR spots, and I netted over 75 spots by close of play, mostly in Germany, Sweden but also one to 4X1RF. Yes, the 6m band was open at 2.00 am clock time. And why not?

By 21:00 the K number was 9 and I looked hard at the 4m map on DXMaps. I have altered this map below to show what it was showing 5 minutes earlier, with my station on it to show where I am on the map. 

The stations in Southern England seem to be working Es into Poland, and there are some Scandinavian stations working across them at 90 degrees. So there must be an Es layer somewhere over the point where the lines cross. As usual, click on the photo to enlarge it if required.
By dead reckoning and a bit of geometry, it looked to me that I was wasting my time calling CQ on 70.200 looking for Poland or the Baltic states. Although the G and EI stations were working due East, I needed to point at the Es layer, which was South East.

It looked like Germany was the best target, so I beamed there (about 125 degrees) and moved to the German allocation (about 70.176 to be precise). One CQ and back came DD8BQA (JO72en 1092km). You can see on the map how this fitted into the geometry of the Es layer being roughly where I though it would be:-
This, remember, is at 21:40 at night (22:40 clock here and later in Germany). I then worked DD3SP, DL4WO, OK1VEC, DJ5MN and DK6SP, ending this phase of Es at 23:36.

What I am trying to get at here is not that I am some great Sherlock Holmes DX finder, but that anyone could do it.

First step would be to ignore the "official" guidance. The latest "news" from a certain National Society says that Es (if there is any this week) will be during the morning and afternoon peak and probably from the UK to Portugal. Great tips there then. And the Weatherman is still going on about the Jet Stream (yawn).

These people are trying to predict Es a week in advance. Pointless, especially as they believe it is a weather phenomenon. My own predictions are about two days in range, and are based on careful study of Solarham and DXMaps - sites listed on the sidebar and for which I am hugely grateful.

Next step is to look for patterns in the maps and point your beam at where there is likelihood of success. Yes earlier I was hoping for an aurora. If I had stuck to that idea I would have been beaming North I would have missed the Es.

And finally, this is purely PERSONAL. I think that the "KST Chat Room" is a waste of time for me. Calling CQ is the way to go here, provided I am selective. Sitting in a cosy chat room trying to set up skeds might work for random meteor scatter, and be great fun, but it just hampers my way of working.

If you use KST, well jolly good. I do not want to have it banned or anything. I am just saying that it does not work for my style of DX hunting. My hunting is not "following the pack" like a fox hunt with hound dogs, no no, no, I am a "stalker". I hunt my DX with guile and tactics.

What a fool I am! It is all pretty random really. But it keeps me happy and it is just as effective as the Weatherman's pontifications about wind in the upper atmosphere.

I think that the more predictions these people make, the more chance there is of some of them being right. And the same applies to me really.

I am foolish if I think I can beat the solar system. It always has the last laugh in the end. But my silly predictions seem to work sometimes, and until I find a better way, I will go on the way I do.

73

Jim
GM4FVM

Thursday 6 August 2015

Shock news, antenna rope "too conspicuous"

News just in -- a Scottish radio amateur has been required to change his antenna set-up due to his blue rope being "too conspicuous".

The "Domestic Authority Chez GM4FVM" has decided that the 4mm polypropylene rope used to "lash up" the antenna is too thick and easy to see and must be replaced.  There is no appeal against the decisions of the Domestic Authority.

Put-upon amateur, Mr GM4FVM (aged 59 years) said "I had bought thinner and darker coloured rope and this decision says it is still too thick and noticeable. Now I have had to buy expensive grey guy rope instead. This decision is an assault on the freedom of all radio amateurs, world wide"



SERIOUSLY, after spending several days getting the antenna up, I had not thought the rope was too noticeable. It is thinner than the rope I have used before. It is not actually guy rope, just supporting the antenna and balancing out the weight of the antenna on one side of the mast.

It all looks graceful and artistic to me, but not to Mrs FVM, or so it seems.
Who could say that arrangement is not beautiful to look at?

And anyway, as soon as I put it up, I heard Victor HS0ZKM from Thailand (which was part of the objective of putting it up in the first place).

Power Reported Distance
Date Call Frequency SNR Drift Grid dBm W by loc km mi
 2015-08-05 23:10  HS0ZKM  7.040024  -21  1  OK03gr  +37  5.012  GM4FVM  IO85wu  9517  5914 
 2015-08-05 22:54  HS0ZKM  7.040024  -20  0  OK03gr  +37  5.012  GM4FVM  IO85wu  9517  5914 
 2015-08-05 20:36  HS0ZKM  7.040024  -22  0  OK03gr  +37  5.012  GM4FVM  IO85wu  9517  5914 
 2015-08-05 19:12  HS0ZKM  7.040022  -23  0  OK03gr  +37  5.012  GM4FVM  IO85wu  9517  5914 

In due course, I plan to raise the power to 5 watts myself, to see if I can reach him.

Nothing lost. It was just lashed up to see what it looked like (and I did not have a problem with it).

Perhaps the moral of the story is never "lash it up to see what it looks like". Do a proper professional job and then it is too late to change.

I was going to lower it and add the tensioners and cut the rope to the right lengths, so I suppose nothing is lost.

I did point out that the birds would find it harder to see the dark grey thin expensive guy wires I would have to buy, but that did not cut much ice.

Nothing else for it but to change the ropes.

Ah well.

73

Jim
GM4FVM

Wednesday 5 August 2015

Fibre Broadband, Ethernet cables and EMC - update.

Well, the "CAT7" screened ethernet cable arrived thanks to eBay etc. It looks much better than the previous one, and it has nice metal shields over the plugs etc.


What you see here is
On the left, the Netgear router (it is just held up with Velcro, hence not vertical yet)
On the right the BT Openreach modem
Between them the thick blue ethernet cable.

The cable tends to try to push the modem over, as it is only 600mm long. Shorter cable, less chance of radiation I reckon.

A shelf might help, as Velcro on the wall is not ideal ...

So that seems to have killed the noise on the bands I use.

Both units come with "wall wart" switching PSUs which are still suspect. More work to do there with ferrites etc. I may replace them with a linear power supply (they are both 12 volt).

So far, I have had no other noise problems with the fibre broadband. It does not seem markedly faster but I have still to do a speed check.

As those screened CAT7 cables seem so much better for EMC purposes I am pondering over buying another couple and doing my neighbour a "free upgrade" for her BT system. It would cost a few £££ but it might knock down the noise level in here.

73

Jim
GM4FVM