Sunday 28 July 2019

Propagation models: what's the point?

Early this morning, from 03-04UT, I couldn't sleep, so did some operating on 14MHz.

Despite the poor solar conditions, I was getting deep into Russia, with a fair number of stations from the M and N grid regions, and the occasional O grid, too.

This is how the FT8 signals were coming and going at the time.  Notice the small number of stations on the far West Coast US hearing my 35W from a vertical delta loop (this propagation was extremely transient, lasting only a couple of minutes):


Now look at how ITUprop was predicting 14MHz, assuming 100W to a dipole as the transmitter (a lot more power than I was using, but a similar overall antenna):

By any standards, that's a very poor model of propagation.  In essence, it's simply telling us that, in the early morning of late July, propagation is broadly and weakly to the east.  In other words, it's telling us nothing at all.

Unfortunately, I failed to select the correct sound input for HRD, because there was an R8 station, and some others, showing very strong echoes, indicative of a combined long and short path propagation at the same time.  I'll catch those sounds again tomorrow morning!

Wednesday 10 July 2019

EURAO - ITU recognition

EURAO has just been recognised by the ITU as a representative body for amateur radio.

This comes as a bit of a kick in the teeth for the likes of IARU, Region 1, whose members often looked very uncomfortable standing next to EURAO organisers.  You could be forgiven for thinking there was bad blood between them, and a wish on the part of IARU R1 not to have someone spoil their party.
Some time ago, when IARU R1 (centre two chaps) met EURAO, with bad body language...

I would link to the story, but the EURAO node seems a bit dead...


Tuesday 2 July 2019

Remembering old antennas.

Whilst trawling through photos of my early childhood today, I came across a fascinating, if not altogether very clear image of how we used to receive TV in the UK.

It's amazing how well the original photo, with a strong orange cast all over it, has been restored in colour.  Yes, I know my mum overfed me!  My dad decided, for his part, to make a garden pond with an old fibreglass boat(!)

The summer of, probably, 1973. 

I remember the antenna very well, even though it's 46 years ago.  A crossed dipole, which was the TV antenna (405-line system, 45MHz - 214MHz in 13 channels).  The rather nice multi-element beam must have been for radio, though I don't recall ever having any radios that were connected to it.

Those large crossed dipoles were entirely lawful without planning permission back in the late 1960s and early 1970s.  Somehow, despite (or perhaps because of) the presence of the RSGB, the law makers managed to quickly diminish antenna rights such that only a 70cm-long Yagi is now considered de minimis.

It's a frightening thought that, 46 years into the future, were I lucky enough to get there, I will be 92 years old!  Life is very short...

Monday 1 July 2019

12m - still hot!

Can you believe this was going on at 22:22UT last night - on 12m?

Wow!