Saturday, November 12, 2011

2m/70cm dual band yagi tests

During the last couple of weeks I have had a chance to evaluate the new 144/432Mhz dual band yagi through the Tuesday Evening contests.
First 2m...the yagi has 5 elements and is tuned well with a vswr of almost 1:1. During the contest I was amazed at the stations that I heard and worked with my Yaesu FT817 with just 5w output power. The rotator is working fine and I was able to test the direction and also side lobes of the antenna. It seems quite sharp, about what I would expect for a 5 element yagi, my old antenna was an 8 element J Beam and was slightly sharper. The main thing was that everything I heard that night on 2m, I worked with just 5w! Conditions were flat, but I worked Hampshire, Buckinghamshire, London, Bristol and the East Coast.

This week on 70cm again the yagi seemed to perform well. This yagi has 8 elements on 432Mhz. I found this a little tricky to get the beam settings right at times, it does seem to have some side lobes and with 8 elements it is not very sharp. My old antenna was an 18 element parabeam, this was obviously much sharper with a higher gain factor. Again, I was quite amazed at how I could hear and also work the stations on 432Mhz with just 5w. G8OHM, M0GHZ, G3PYE/P just some of the stations worked from all over England.

I am really pleased with this antenna, it was easy to put together and set up and does not take up too much room. The configuration of the elements look quite strange, usually a normal yagi has the longest as the reflector and each element gets progressively shorter. With the dual band yagi, this is not the case, all to do with the tuning I guess. The yagi is a bit of a compromise really, but it puts me back on the map again as a station especially when conditions open up to the continent on 2m and 70cm. I also realised how my location makes a difference, I am on the top of a hill about 114 metres asl with a good take off to the South.

Sunday, November 06, 2011

Bolton Technical College - the end!

The end of an era!

I have a lot of memories here in this building, right from doing my 11 plus test here up to teaching IT there up to a few years ago. I have mixed feelings about the demise of this huge building, inside it was a maze of corridors, very claustophobic and quite depressing. I spent five years on my day-release training when I was an apprentice from 16 years old to 21 years old. Most of the time was spent in the basement rooms where the electronics labs were kept. It was awful really, you couldn't see out of the windows and in the basement were numerous workshops for bricklaying, plumbing and construction skills. Each year I would have to take my exams in the 'Great Hall'. When I finished at college in 1975 I vowed never to go back there again. I can remember some of my tutors then...Mr Smith, Mr Tudor, Mr Duncan. I remember once going up onto the roof of the college to suss out putting an antenna up to run a radio station

I took my Radio Amateur Exam 40 years ago this year here at the college!

After 15 years away from the college I found myself having to complete my GCSE English at college and did my exam in the 'Great Hall'. After I got my degree I did my teacher training PGCE. My second placement in my PGCE was here at Bolton College teaching classes in electronics, Video Recorders and CD Players. My six week placement was very enjoyable, this time I was in the same electronics labs that I did when I was an apprentice, but I was in charge!

Later, I decided to do some IT teaching at the college on Saturday mornings and also during evening classes. I taught RSA CLAIT to adults which I enjoyed a lot. The only problem was the college room was on the third floor and the staffroom was on the first floor. To get into my room I needed a key which had to be obtained and signed out in the staffroom. Trouble was in the evening that the staffroom was also locked! You can imagine the situation each week when I had to first find the staffroom key so that I could get the room key...nightmare!!

To make things 9.00pm when the class had finished I had to do the same again to return the key...and if you were not out of the building by 9.15pm you had a good chance of being locked in the building! Oh....and the was on a huge block of mild steel that weighed a ton so that nobody would nick it!!

My Dad also went to Bolton College learning about textiles and weaving, like me later, he did a day release course and night school.

Well...let's face it...that building was not fot for purpose, the new college building is amazing...a step into the 21st century!

17th December 2011... now its gone!!

Saw some good bands here in the Great Hall back in the 70's I remember a band called 'Strife' who were excellent with hi-tech strobe lights.
Later, there was the monthly computer fairs in the Excel Centre, a bit crap really, nothing like the one at Bowlers at Trafford Park.

RIP Bolton Technical College!

Wednesday, November 02, 2011

75 Years of television!

"At 3pm on 2 November 1936 the BBC began the world's first regular hi-definition television service, from Alexandra Palace in North London. As part of this, two different systems were being tested on alternate weeks for six months: John Logie Baird's 240 line mechanical system, and the EMI-Marconi 405 line electronic system. The latter was to prove the winning system."

True analogue natives will know that this is a landmark of analogue technology. I wonder if people 75 years ago who saw the first BBC transmissions had any incline into what was to come in the future. What on earth did people do before television? When I am teaching children at school I am amazed at their concept of technology. In their minds television has always been there, they cannot even imagine a world without television!

Sceptics thought television was a gimmic and said that it would never catch on. After all, nobody could possibly afford to buy a television!

'Television? The word is half Greek and half Latin. No good will come of it.'

I remember my first television in 1958 when I was 4 years old and lived in Draycot Street, I watched things like 'Four Feather Falls', 'Popeye' and 'Torchy the battery boy' in those days ITV had just arrived. The first BBC transmissions from Alexander Palace was 'High Definition' black and white. What a difference to our present digital 'High Definition.'

Now my English teacher at secondary school had another name for television, he would call it 'The Devil's Lantern' or 'Goggle Box' ... he wasn't far wrong, our lives are are controlled by television. Children have forgotten how to 'play' and when they do, it usually centres on something that they have seen on television. Having said that, how can you take away those television moments like the Moon Landing in 1969 or England winning the World Cup in 1966 in 'hight definition black and white'....priceless!

Television is a fantastic communication medium, I have spent most of my life working with televisions. In 1973 I even transmitted my own television transmissions under my own licenced callsign G6AIW/T along with Neil G6AIG/T.

My original 'Hi Definition' test card that I used.
In 1967 I went to visit the Winter Hill transmitting station during an open day, something I will always remember. Later I spent many Sundays at the ITV transmitter with my Uncle who worked there. I got to know how it all worked and looked in awe at the analogue equipment and water cooled transmitters.