Wednesday, December 28, 2011

Radio Communication Handbook

Gosh! I have wanted one of these for years, when I finally decided to get one for Christmas the other year it had gone out of print. Now I got one for this years Christmas present!

I have the older editions (two volumes) along with the VHF / UHF manual. They are excellent publications, but the projects in them are outdated. The latest edition is thoroughly up to date with the latest technology both digital and analogue. It has a nice balance, with some specialised projects using valves. The principles are still the same and it takes you back to basics. With all the digital technology in the world, you can't change the formulae of Ohm's Law, Resonant Circuits and Antenna principles. There are also a lot of useful and updated charts and graphs to explain things like radiation patterns and circuits.

I will always treasure this publication, certainly worth the £30!

50Mhz Halo Test

The final piece in the antenna jigsaw, putting up the 50mhz Halo.

When I sent for the antenna I wasn't sure just how big this antenna would look and also how it will perform. Assembling the halo was quite easy, but the instructions didn't mention how to tune this thing apart from the small variable capacitor on the connector block where the coax connects. The halo frame is adjustable and on the drawing it shows 4 inches as the extension length from the adjuster. The delta match is also variable in length, so after first assembling the unit I connected it to my FT817 to adjust for best vswr. After a lot of fiddling I got it down to 1:1. Now it was ready to fix up on the mast. The halo came with a good quality clamp and was easy to fix on the mast, but was very close to the satellite dish.

When I tested the halo on 50Mhz I was a bit disappointed. At first I couldn't hear the Buxton beacon, it is drowned by another carrier on top of it. Eventually, I managed to find it which although stronger than it is on the discone antenna, I would have thought it would come in stronger. When I transmitted on the halo the vswr went up very high, something is obviously wrong. I now need to get the ladders out again to maybe move the halo away from the satellite dish and re-tune the antenna.

I will reserve my judgement until later when I get chance to optomise the antenna and try it again.

Latest update - 28th December 2011

Today I took down the halo to make some adjustments and measuring. If you buy one of these from Moonraker (or anywhere else for that matter) the rather vague instructions that come with it are wrong! It shows a measurement for extending the square of the halo and shows it as 4 inches. The halo is tuned far too high in frequency and I found that I had to extend the square and delta match right to it's limits. Even at this, it tunes best at the top end of the band.
My halo is on a mast outside on the side of the house. I spent a long time at the top of a ladder fiddling with it and eventually giving up! After some thinking time it occured to me that a halo is of course just a 'bent' half-wave dipole, so I took a tape measure and measured the length excluding the insulated part. It turned out to be far too short for a half-wave at 50Mhz. I then adjusted the overall length to as near as I could get it. Even with everything set at it's extreme, it was still slightly short. After that I was able to tune the VSWR with the trimmer.

So now that I have the halo tuned I used the antenna during the 50Mhz contest to see how it performs now. VSWR is now down to 1.5 :1 and I must admit that every station I heard I managed to work even though conditions on the band were poor. It was a little anoying when other stations were using yagis and my halo is omni-directional. I would feel more in control to have some forward gain. I am also not happy with the position of the halo, it is screened in some directions because it is sandwiched between the houses. Would probably work better in the clear up on the chimney perhaps. I could hear the Buxton Beacon at s9, but I still think that it should come in louder than that. overall verdict on the 50Mhz Halo... It is adequate for general use on 50Mhz, but I would prefer a 2 ele HB9CV similar to my 70Mhz. I am limited for space though, so the Halo is a bit of a compomise.

Wednesday, December 21, 2011

Jean Genie Genius

I just watched a piece of television pop history tonight! Shown for the first time in 39 years!

David Bowie singing Jean Genie live on Top of the Pops back in January 1973 (a good year!) I find it difficult to believe that the BBC erased tapes of TOTP and other series after they had been shown! Maybe it was done to save money and re-use the tapes like we did with audio tapes. Well done John Henshall, the cameraman who saved hundreds of copies of stuff wiped from tapes.

"A retired cameraman has been speaking of the moment he realised he owned footage of David Bowie on Top of the Pops which was thought to be lost.
John Henshall, 69, from Stanford-in-the-Vale, Oxfordshire, retained a copy of Bowie performing Jean Genie in 1973.
He said: "I just couldn't believe that I was the only one with it. I just thought you wouldn't be mad enough to wipe a tape like that."

Mr Henshall said he only kept it because he wanted it for his showreel.
In the footage he used Telefex Fisheye lenses which he had designed himself. He also ended up in the background of one of the shots.
After the recording he asked producers for a personal copy on 2in (5cm) broadcast videotape.'Rarer than rare'
Mr Henshall said: "I didn't realise that it had been wiped by the BBC.
"They'd been looking for it for years, hoping that somebody had maybe pointed an 8mm home movie camera at the screen, because there was no VHS in those days. "

It amazes me how much television history has been 'wiped' over the years. On Monday I watched the film 'Hugo' which is a wonderful story of a movie-maker who destroys his celluloid films and finds them again by someone who saw the value of this analogue history.

Sunday, December 18, 2011

70Mhz receive converter

My versions of the converters. The top photo is the 50Mhz converter and the second one is the 70Mhz version. I currently use these as part of my transverters. I also made one for 144Mhz in a similar style. The 50 Mhz converter has a 3sk88 in the front end, while the 70Mhz uses 40673 mosfet. Note the different 28Mhz IF inductors, the 70Mhz uses a small torroid, while the 50Mhz uses a 1/4" coil former.

I ought to know the circuit of this converter by heart now, I have built so many of them for different frequencies.

My first attempts at a 144Mhz converter with an output frequency of 2 - 4Mhz (remember tuning high to low?) was not the best. It took ages to get things right with a FET front end and mixer. I could never seem to get it stable even after several rebuilds. Later, when I got the Yaesu FT101E I wanted to use this as a tunable IF of 28 - 30Mhz, so I decided on this design. It used two dual-gate MOSFETS, and also used feed-through decoupling capacitors and leadless discs. They were very easy to use and the circuit was very stable!

I first built a 144Mhz convertor which formed part of my transverter project, and then later built one for 70Mhz and also 50Mhz. All with the same layout, but different crystal and coils.

I still use all of these in my transverters, all are sensitive and stable

A great circuit, recommended for anyone wanting to build one of these as part of a project.

In the circuit I replaced the 3N140 with 40673 MOSFETS and then later used GASFETS like the 3SK88. My transverters for 144Mhz and 50Mhz have 3SK88's and for 70Mhz I used 40673's.

Monday, December 12, 2011

DF8QK 1296Mhz Transverter

Years ago I got hold of some partially completed DF8QK circuit boards. At first I built the 1296Mhz receive converter and after a lot of messing I finally heard a signal for the first time on the 23cm Amateur Band. Next I completed the three stage pre-amp and although quite noisy, managed to get it working as well.

This project took me ages to build and eventually I partially completed the transmit mixer. I assembled the units using copper clad board to make boxes for each unit with bnc sockets and plugs to connect between each unit. It was a bit of a nightmare to have, with wires everywhere!

The transmit mixer worked fine, but each time I wanted to use it I had to tweek some of the trimmers to make it work properly. I was truely amazed when I managed to work a station in France during excellent tropo conditions with just a few milliwatts of power!

Having worked a few stations on 23cm, my next project was to try to put all these units into a case and also build the power amplifier to give it some more power output.

For a while the transverter worked, but with a few problems with alignment that had to be constantly tweeked again. The big problem with the 23cm band is that nobody uses it unless there is a contest or tropo opening, so I never really new how well the transverter performed.

I still have the transverter, but it has not been powered up for years as I 'lost' the circuits and alignment details.

Last week I came across an old floder in my attic and guess what was in it? The circuits for the DF8QK! I was my task is to try to get this beast working again after so long. I don't know if it will be successful, but you can but try!

Sunday, December 04, 2011

Pye Bootmount Cambridge

About the same time as using the Pye Ranger on 70Mhz, I also had a mobile set up for 144Mhz. This consisted of a Pye Bootmount Cambridge complete with cables and A35 van to put it in. This was my first car! Originally the small dashmount control unit was mounted at the front and the main unit was on the floor in the back of the van. There were 6 crystal controlled channels and I used a home made 1/4 wave mag mount on 2m. (The magnet came from an old tv focus unit) At first I used it on AM, but later I fitted an FM discriminator (TBA120a) and modified the RF circuit to transmit in FM.

Later, I took the bold step of making the bootmount into a dashmount and building a front panel with all it's controls fitted to the side of the main unit. I then designed and built my fist ever digital LED digital readout that displayed the channel number (R6, S20, S21 etc...) It used a huge matrix of 1N914 diodes. It worked really well!

I used this set up for a while until I eventually bought a Sommercamp FM mobile at a rally. I still can't remember what I did with this Pye Bootmount Cambridge, I know that I also had a dashmout Pye Cambridge later. I think I must have taken it to a bring and buy stall at a rally.

Pye 70Mhz Ranger

After my last post I got to think about the old Pye Ranger that I used for a while to get me onto 70Mhz. I borrowed the rig from Neil G3ZPL, who used it himself for a while. This was a mean rig with a QQVO-320 valve in the final giving about 15 watts output. Although I called it a Pye Ranger, I don't think it actually had a name at that time.

Production life: 1949 - 1956

Standard frequency range: PTC114, 60 - 100 MHz,

Transmitter RF output: 10 -15 Watts AM

Primary model variants: 6, 12 or 24 Volt dc operation,

1 or 2 channel operation, PTC114Z-115Z later version using QQV03/20A PA valve.

I can't remember how I powered this rig, I think I must have wired this to a high voltage power supply. I remember using this AM rig to work cross-band with Neil G3ZPL.

Saturday, December 03, 2011

70Mhz antenna - HB9CV Review

At last! Some stations to work on 4m with my new HB9CV!
Last week was the Tuesday evening activity night contest on 70Mhz. These don't seem to happen every month, so I have had to wait for this one to come. I have always liked 4m, years ago I had a Pye Ranger AM set with it's all valve line up. I used this for quite a while until I built a 4m Transverter which I am still using now. I had lots of fun during VHF NFD back in 70's and 80' when I always opted to operate of 4m.

4m and 6m tranverter with the old Yaesu FT101E and HF Z-match. This is my present set up for 4m.
For a while I used a 2 element band 1 antenna which was fixed on the side of the house, eventually, it fell apart, so I was qrt on 4m for a long time.
I bought the HB9CV from Moonraker, which arrived after first being sent a 2m, 4 element instead of the 4m 2 element. This was then replaced with correct yagi but minus the extension rods required to tune the antenna. After an e-mail to Moonraker the rods were dispached separately. The antenna was easy to put together, but the instructions are not very clear, you have to work out yourself how to fix the driven element. Inside the the terminal box is an airspaced 'beehive trimmer' - not seen one of these for years! The trimmer is used to tune the antenna to obtain best SWR. This I found quite straight forward. This antenna has a rear mounting bracket, which is fine, but the supplied clamp was poor and even when fully tightened the antenna keeps dipping down. The extension rods have to be tightened with the screws fitted, I still don't understand why this kit has extension rods, why couldn't they make it all in one piece? You need lots of vaseline to keep the screws from rusting, they are stainless, but only coated.
The HB9CV is mounted on a rotator, so my first thing was to check the Buxton Beacon on 70.000Mhz. This was coming in well over s9, very strong!

On Tuesday conditions were poor, but I still managed to work 16 stations, my furthest being down in the midlands with just 5 watts. I like this antenna, it was quite sharp and had a good front to back ratio. I guess the HB9CV is actually a 3 element yagi with the driven element bent between the director and reflector. It is quite a neat antenna which doesn't take up much room, but performs we
It is a pity that 70Mhz is not used as much as it should, when conditions are good you can work long distances. I remember once working stations on cw during a good Aurora.

I found this design on the internet and used it to make a 432Mhz version of the HB9CV. Thank you to the German station that made the design. It works perfectly!
For 70Mhz just put in your own measurements (lambda is the wavelength of the band eg: 4 metres, 2 metres, 70 centimetres)

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.

Thursday, October 27, 2011

G5RV Antenna

The next part of my antenna erecting project was to look at an antenna for HF, particularly for 10 metres with the sunspot maximum. Now my history of HF antennas has been very limited. The present antenna is a very short long wire which doubles back on itself fed with a long piece of coax. Last week I did a lot of research on dipoles and baluns, I also did some measuring in the back garden to see what length of antenna I could get away with. When I did the measurements I realised that I could just fit a half-size G5RV antenna. The half-size G5RV is a dipole with two 26.5 feet top and fed with 16 feet of 300 ohm ribbon cable. This then connects with a so-239 socket to any length of 50 ohm coax. I decided to try it out and take down the old antenna!

I sent for the G5RV kit from e-bay which arrived almost the next day! First a trip to Modern Radio to get some RG58u coax and some pl-259 plugs then out came the ladders!

So, after putting up the new antenna the question going around in my head was 'Will it work on all bands?' This antenna is only designed to use from 40m - 10m bands, maybe it will be useless on 80m and 160m. I also read about other people having problems tuning this antenna.

When I finally wired it up and connected it to the Yaesu FT-817 through the MFJ-945E tuner I was totally blown away!!

I could hear things that I could only dream of with the old longwire!

The dipole centre with the ribbon cable attached.

The ATU (Aerial Tuning Unit) did it's stuff perfectly giving me an almost 1:1 SWR on all the bands including 160m and 80m. On some bands it didn't even need the ATU, it was aready resonant, particularly the 40m band. I am very pleased with I want to try to work some stuff on 10 metres.

Sunday, October 23, 2011

28Mhz Opening!

This week has been amazing on 10m!

The band has been open during the day and I have heard stations from North and South America sounding like locals. lots of Italian and Russian stations and today I heard Brazil, Malta and Greece at incredible signal strengths.

I have decided that now is the time to change my HF antenna. If I can hear these stations with a (short) longwire and a lot of noise, I wondered what I may hear with a dipole or G5RV antenna.

After a lot of thinking and research, I have decided to replace the very poor longwire with a half-size G5RV antenna, so now I have ordered one from ebay. I am on holiday this week, so I will put up the new aerial and try it on 10 metres. Trouble is that because it is a half size G5RV, it may not work well on 80m and 160m, but maybe my tuner or Z-match with compensate for that.

I am still amazed at the discone antenna. It seems to work well to receive stations on 10m as a vertical without all the noise and this morning it did the same on 160m when I listened to the 1963 net. Transmitting is not good though, very high SWR!

It is difficult to imagine how the sunspots affect the 10m band. For 10 years the band is dead with very few stations, but now it is jam packed with stations from all over the world. What a wonderful phenomena!

Monday, October 17, 2011

Power to the people!

Am I just thick and not very intelligent or am I missing something?

Electricity comes from a generator at a power station, whether it be standard, nuclear or green?

It comes down the National Grid to our substations and then through the wires into our houses...right?

Gas comes from the North Sea or via pipelines from Europe?

It is then piped to our houses from the same source...right?

So why on earth do we have 'Power Suppliers' like E-on, PowerGen, Scottish Power and other hangers on! How is it possible to 'buy' your power from a supplier when it all comes from the same place and down the same wires and pipes. This must be the biggest con ever!!

Surely, if we just had one supplier regulated by OFGEN and a simple pricing tariff we would all save money!

Instead of constantly competing with each other, why don't they all get together and use some 'muscle' to bring the wholesale prices down instead of lining their own pockets. Now Mr C. wants us to keep changing our suppliers to get a better deal, why the hell should we have to do that!

Does anyone REALLY understand how this industry works...because I don't!!

Simple a wind generator!

Sunday, October 16, 2011

Beam me up Scotty!

A great weekend for erecting some aerials!

At last I managed to get all the antennas together. I now seem to have more than expected, I ordered a 4m, 2 element beam from Moonraker and got a new 4 element 2 metre antenna! Not quite what I wanted, but they said I could have it at half price if I wanted while they sorted out the correct item. That was good because it would be ideal for portable use on Winter Hill.
So...the correct item came minus some parts! A couple of days later the items missing came through the post and the problem was solved!
I assembled the array in the garden and tuned the 4m HB9CV before putting the array up.

The first part of the project was completed a couple of weeks ago, the rotator and mounting brackets ready for the array to be fitted. This weekend I put together the array and made sure everything was greased with dolops of vaseline! Great stuff Vaseline, if you ever want to take the antennas down, you will find that the bolts are rusted. Vaseline cures that problem.

Now I have been up and down the ladder like a fiddlers elbow, but carrying the completed array up the ladder and fixing it into the rotator is scary! I called on my mate Andy to carry the array up the ladders and fix them to clamps.

It is quite a neat array, considering it is for 4m, 2m, and 70cm, a 6m antenna is too large, so I may go for the halo and mount it underneath the rotator.

Tonight I tested I can hear the Wrotham Beacon in Kent for the first time in over 10 years! I can also hear the Buxton Beacon coming in at 5-9+ on 4m!

Great fun with the perfectly...can't believe I got it on ebay for £19!

I am sooo pleased that I still know how to put up antennas after all this time, putting the array together seemed like second nature, I have done it so many times.

Thursday, October 13, 2011

On the air!

Here I am age 17, this photo was taken just before I got my licence!

I received my licence documents through the post 40 years ago today!

Now I remember this well, I came home from work at teatime while working at Telefusion Ltd. When I came in the letter was waiting, at the same time along come George G3ZQS (in his slippers) As I opened the envelope, George said "Come on...what is the callsign then?" "G4AQB" I replied...."Oooh...A Queer Bugger eh!!" said George with his usual razer sharp wit!

After George had gone I rang up Neil G3ZPL to tell him that I had my callsign! I then called Neil on 160m so that he could be my first (legal) contact.

Here is a section of the very first page in my logbook back in 1971.

Wednesday, October 12, 2011

G4AQB - 40 years today!

OMG! Today is a special anniversary! I got my Amateur Radio Licence 40 years ago today!

The wonderful sound of G4AQB...

I was 17 years old then and worked so hard to study for my Radio Amateur Exam. I had been interested in radio since I was 13 years old, and my first radio shack was in a leaky concrete shed. I spent my time there every night building and constructing my own equipment. At 17 years old I was one of the youngest radio amateurs in the country!

Now today after 40 years I am building my new antenna array and continue to listen on the amateur bands. There have been some times when I have not had time for radio being a teacher, it steals all your leisure time. Now as I look towards retirement, radio is such a wonderful hobby even in this digital world. I have never forgotten how to read circuits and build stuff of my own. Maybe when I get more time I will start to do this in a big way again.

The day I passed my Morse Test!

Saturday, October 08, 2011

Sunspot Maximum

We are about to reach the peak of the 11 year sunspot cycle!

So what does it mean? Well, today I listened on the 10m band during the day to find the band open with lots of stations coming in from all over the world! America and Brazil coming in at 5-9 with little noise. Fantastic!

There is much more to come as the predicted maximum is between January and May 2013 with a steady build up of sunspot activity.

So what happens at Sunspot maximum? Basically, the 'F' layer of the ionosphere becomes more ionised and is able to reflect radio signals in the upper short wave bands that would normally have passed through into space. So Amateur bands like 28Mhz, 50Mhz and even 70Mhz will be affected causing long distance radio communication across the world. This will tend to happen more during the day and communication can be made even with low power.

I am looking forward to seeing what stations I can hear and work with my Yaesu FT817 and 5 watts. I still have my FT101E which will give me 150w if I need it!

I remember back in 1980 at the sunspot maximum when I had a converted Belcom Liner 2 in my car and a 27Mhz CB antenna. The stations that I worked with just 10 watts was amazing! I talked to America, Russia and even a guy on a ship in the Panama Canal while driving to work!

I also remember driving home from Yorkshire with Kathleen, my wife, who was pregnant at the time watching an amazing sunset with 3 or 4 large visible sunspots, that was in 1980.

Thursday, October 06, 2011

Steve Job - digital hero

Sad news today on the death of Steve Job, the Apple guy!
Probably one of the most influential person in modern times, he has written the future of communications and digital technology. His innovations of the Apple Mac, ipod, iphone and ipad set the standards for others to follow. A sad loss for modern digital technology.

"Thousands of people all over the world have also been attending Apple stores to leave flowers, notes, and apples with a bite taken from them to mimic the company's logo.
Apple's leading rivals such as Microsoft, Google, Sony and Samsung all chipped in with glowing tributes.
GS Choi, chief executive of Samsung, which is embroiled in a major court battle with Apple on patents, said Mr Jobs was an "innovative spirit" who "introduced numerous revolutionary changes to the information technology industry".
In his statement, Bill Gates said: "The world rarely sees someone who has had the profound impact Steve has had, the effects of which will be felt for many generations to come. For those of us lucky enough to get to work with him, it's been an insanely great honour."

Mr Jobs built a reputation as a forthright and demanding leader who could take niche technologies - such as the mouse and graphical user interface, using onscreen icons rather than text - and make them popular with the general public.

He introduced the colourful iMac computer, the iPod, the iPhone and the iPad to the world. His death came just a day after Apple unveiled its latest iPhone 4S model.

Sunday, October 02, 2011

144Mhz / 432Mhz dual band yagi

I spotted a cool dual band yagi on Ebay, 5 element 144Mhz and 8 element 432Mhz all on one boom with a single coax feed. This sounds like just the job!

I ordered this antenna along with a 2 element HB9CV yagi for 70Mhz. I wanted to add a 50Mhz yagi as well, but it would be too big. The weather this weekend was fantastic, temperature 27 degrees, a real indian summer. Ideal weather to put up some new antennas!

It has felt like Christmas this week! I ordered some new antennas and a rotator, at last I am going to have my antenna array back again after many years. My first array was put up on the 24th September 1973. I then had an 8 element yagi for 144Mhz and an 18 element parabeam for 432Mhz made by J-Beam. In 1977 I moved them onto the chimney at my present location and they stayed there until about 1999 when I took them down and threw them away!

Would you believe that I bought this rotator from ebay, brand new from Germany, it cost only £19! Deciding on the antennas was not easy, I don't want a huge array of yagis, but I need something small and compact because this is going to be mounted on the side of the house and can be seen clearly from the street.

I was still waiting for the 70Mhz yagi, but I still wanted to make a start on the array, so my first visit was to B&Q to buy the fixings. Having looked on ebay and the internet, the prices at B&Q was quite reasonable for the 6ft aluminium masts and fixing bracket. Next I needed some coax cable, so a trip to Modern Radio was next. I haven't been to Modern Radio for quite a while, I always enjoy going there...lots of memories! I wanted some good quality 50 ohm coax, but not the expensive thick stuff. Diane at MR showed me some 'Mini RG8' coax instead of the cheap RG-58u. Good stuff at a good price (70p per metre) ideal for my set up, so I bought 20 metres and some BNC plugs.

Spent the rest of the afternoon drilling the wall and assembling the new 144Mhz / 432Mhz dual band yagi. This was easy to assemble, all I had to do was put the elements into the coloured numbered holes.

Now i'm all set up just waiting for the 4m yagi.