Nice exhibition today in Bolton town centre ‘Get ready for Winter’ showing the emergency services along with Bolton Mountain Rescue, Gritters and Snow Plough (great for the kids) and RAYNET. Here I am sitting with Jack G8HIK from the local RAYNET group.
Melissa and Cameron looking at the Fire Engine.
Over the last year it has been great to see the impact of amateur radio on the younger generation through the Tim Peake amateur radio contacts with schools. I thought that I would like to share my own experiences and sent it to Practical Wireless. I am so pleased to see it printed in this months magazine!
Today I became a licenced Radio Amateur 45 years ago! To celebrate tonight I fitted my new classic ‘ON-AIR’ sign. I have become much more active over the last few years since I semi-retired. I have tried out modes that were never invented when I first got my licence, PSK, JT65, Packet. I have avoided the latest digital technology like DMR, don’t really see the point of it. Using all commercial rigs now, back then I had to build everything myself, but now I am starting to build again and am really enjoying using the soldering iron! Now I have a proper ‘shack’ and it is looking like a true ‘toys for boys’ room.
My letter that I received today 45 years ago.
My very first contacts in my Log Book from today 1971.
In 1971 I was 17 years old and my Dad took me to the Liver Building in Liverpool for my morse test. I had to arrange time off work as an apprentice at Telefusion. We travelled down the East Lancs Road into Liverpool, I remember shops having metal shutters, something we never saw in Bolton then! When we arrived my Dad stopped a man near the docks to ask for directions, he told us how he was on strike, this was normal!
We entered the Liver Building and climbed up three flights of stairs to the maritime bit for my test. My Dad waited outside when a man came along and I was taken into a small, long room with a table with three morse keys, one made of solid brass.
“Try them out” the said! When we were ready he sent me morse code groups at 12wpm. I was happy with that, but when it was my turn to send I thought I had fluffed it! The guy laughed and said “You held on a bit there….but fine…you have passed!”
Well. you can imagine…it was like passing my driving test! I was over the moon!
Now 45 years on today I can still remember and occasionally use morse code taught to me by George G3ZQS, a great guy, but now silent key. George made his own tapes to help me learn morse code, he grouped together the letters in to help remember the code. The first were A, W and J, followed by E, I and S, then T, M and O, then N, D and B… a simple but very effective way of learning morse code! Thank you George!
The next part of my EME project is to build a 432Mhz yagi to use with the telescope mount for tracking the Moon. I looked at the possibility of buying a yagi, but really I can’t justify paying £60+, so I decided to find a suitable alternative. I found details of the ‘Cheap Yagi’ by Kent Britain, WA5VJB, it is easy to build using a piece of wood for the boom. I downloaded the design details and set about collecting the materials. I needed something to make the elements of the yagi, so after a search on eBay I found a company that supplies 1/8″ Aluminium welding rods, 18″ long at a bargain price of 25 for £6 including post. A trip to my DIY shop to buy a piece of wood at a cost of £1.25 and I was ready to start building!
First, I measured and marked out the places for the elements. The measurements for length and spacing are simple ‘Cheap Yagi’ are simple, no need for a micrometre! Then drilled holes to take the 1/8″ Aluminium cut rods for the elements.
The driven element is made from 10swg copper wire, bent to form a J shape. The driven element is quite unusual and I still don’t understand how it works.
Almost finished, 11 element 432Mhz yagi, just needs the feed and some glue to secure the elements to the wooden boom.
After attaching the feed to the driven element, which is simply soldered direct to the copper wire element, it was time to test the yagi.
Now the problems start, measuring SWR at 70cms is not easy, my UHF SWR meter was telling me that the SWR was 1:1, but my Yaesu FT857D was showing a high SWR. I didn’t know which to believe! I decided to switch the FT857D display to show SWR, which, sure enough showed a very high SWR, so I used this to try to get the SWR down to a usable level. I could check with the meter where the SWR lowered across the band. In fact it was lower at the LF end of the band, so I then trimmed the driven element to bring it into the band. Not 1:1, but seems alright now and no longer giving the low SWR alarm. I heard a couple of stations on 432Mhz FM and the yagi seems to receive fine! May be good to try out the beam in the next Tuesday evening contest on 432Mhz, which is next week.
Conclusion: An easy to build 8 or 11 element yagi costing pence and ideal for trying out EME on 432Mhz… lets see how it performs!
I have been thinking about using a suitable VHF / UHF preamp for a while now. It would be nice to have a preamp that I could use during the Tuesday evening activity contests as well as having one to use for receiving JT65b signals with EME as part of my Moonbounce project. The PGA103+ is a low noise, high dynamic range preamp which will operate from 50Mhz up to around 3Ghz. Being wide band brings it’s problems, but it is very versatile and sounds like just what I need at the moment. I decided to buy a ready made preamp board from G4DDK, the components are all surface mounted and I have not yet attempted to make anything like this with my limited soldering skills! The G4DDK board is tiny and my first task was to make a suitable case with N type sockets. The G4DDK board has fittings for SMA sockets, but I really needed either BNC or N type to connect the coax.
The housing is built from double sided copper clad board, I have had a lot of experience in the past using this, many of my earlier projects used DS board. It is easy to cut, drill and solder into cases. In the photo you can see the N type sockets fitted and also the G4DDK board.
My first attempt caused some problems, the preamp board worked, but was rather unstable, a rethink was required…
Adding a screen between input and output and making sure that the earth side of the preamp board was thoroughly earthed to the case cured the problem!
Now I just need a lid out of DS board to complete the project.
Testing the preamp on 144Mhz seemed to work fine, bringing GB3VHF from just below the noise to a reasonable level above the noise. I now need to test on 432Mhz and 1296Mhz to see how it performs.
Call me crazy if you like, but I have become hooked on this Moonbounce using JT65b. I am sucessfully making normal contacts on HF with JT65, this is such an addictive mode of operation, quite theraputic!
My goal now is to try to receive a signal using EME, something that up to now has been imposible with other modes for me. So I have set about building an antenna system for 144Mhz and 432Mhz with a vision of actually having a QSO through EME with the minimal equipment. The first part of my project was to adapt a 144Mhz yagi (which I already have) to fit my Celestron computerised telescope mount. I have been using the computerised mount for years now to take images of the Moon, planets and other deep sky objects. If I can set up the computerised mount with the telescope and then replace the telescope with a yagi antenna the mount will then track the Moon in real time. My next task was to make a ‘wedge’ to fit the mount out of wood and a plastic tube screwed to it so that the yagi can be placed inside. Using the tube also allows for changing the polarity of the yagi anytime I want to. For this I used some plastic waste pipe from B&Q along with some modified mounts. This worked fine, but I needed to overcome another problem, the weight of the yagi needed a counterbalance on the other end of the tube to keep it all stable. I solved this problem by using an old transformer!
Four element yagi screwed to a broom handle and pushed into the plastic tube for the computerised telescope mount. At the bottom is the old transformer acting as a counterbalance to keep it all stable.
My next task is to build a 432Mhz yagi and try out the 144Mhz yagi to see if I can receive anything on JT65b…..fingers crossed!
Like Slade said back in the 70’s “Ma…mama we’re all crazy now” but this is not as crazy as it sounds having read the latest stuff about EME and JT65b.