Construction

For many years I have constructed most of my equipment. Starting when I was 13 years old I made simple electronics projects. My very first was a mulivibrator kit made by my Uncle to introduce me to electronics. I later made it into a simple Electronic Organ and my Father built me a small wooden keyboard to go with it. I also built a doorbell using a multivibrator and AF amplifier.  My next project was an intercom and I remember wiring this from my bedroom to the kitchen. Other projects included  building a Metal Detector, Light Transmitter and Receiver, an Oscilloscope (that I built at school), multimeter, signal tracer, Aerial Tuning Unit, Beat Frequency Oscillator (BFO) and all this before I left school!

My first major project was a Topband Transmitter that I built from Short Wave Magazine. It had a line up of EF91 (VFO) EF91 (Buffer) and 5763 (PA) modulated by an ECC82 and 6BW6 valves. A great project that got me on the air when I got my licence in 1971.

I wish that I had taken photos of my early projects. I have some of my later projects that I still use. Here are some of these later projects mainly from the 1980’s and 90’s.

My pride and joy – The G8AMU VHF/UHF Multimode Receiver. Coverage 28MHZ, 50MHz, 70MHz, 144MHz, 432MHz and 1296 Mhz.

Eddystone 898 Tuning Dial (lovely!)

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I remember buying the Eddystone 898 dial at a rally which cost £8 at the time. On the left is the 10.7Mhz IF Module and TBA120A FM discriminator, then the 28Mhz Mhz RF Module. In the middle is the Audio amplifier and on the right is the SSB unit with the filter, Diode Mixer and SL1600 integrated circuits. Above is the Squelch module. It is actually a 28Mhz receiver with added converters for all the VHF bands. I built this receiver around 1980, but it is still in use today!

144Mhz Transverter

Looks a bit like the Microwaves Modules Transverter, but completely home built.

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After many attempts at building 144Mhz converters correctly, I finally got the hang of building solid state VHF equipment. I have worked stations all over Europe using this transverter. Just 10w output, but still works fine driven from my Yaesu FT101E.

Dual 70Mhz / 50Mhz Transverters.
This is a project that is still in use today. I currently have a Yaesu FT817, but it does not cover 70Mhz, so I use this during contests on 70Mhz SSB driven by my Yaesu FT101E. When I first built this transverter it opened up the recently (at the time) 50Mhz band. Both bands run about 5w output. Now I have a halo for 50Mhz and a HB9CV for 70Mhz. Still going strong!

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4m transverter inside

When I built this project I used the cases of old UHF Television tuner units which had built in feed through capacitors for connecting. A really good idea, it kept construction neat and made it easy to build modules.

 

DF8QK 1296Mhz Transverter

Probably one of my more ambitious projects was the DF8QK Transverter. The 23cm band is one of the most difficult to get equipment running. This one was no exception. I spent many hours building and aligning this transverter.

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The transverter was built in modular form using stripline technology. The top board is the crystal oscillator and multipliers followed by filters. The middle board shows the transmit balanced mixer and 1296Mhz output amplifier. On the right is the receiver diode mixer module (enclosed) and the 2 watt 1296Mhz Power Amplifier. At the bottom is the three stage RF Pre-amp consisting of 3 x BFR34 transistors.

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The amazing part of this project is that the transverter actually worked after a lot of fiddling and re-aligning. I still use this transverter even now, driven by my now ancient Yaesu FT101E during Tuesday evening activity contests. On 23rd January 1983 during an opening on VHF / UHF  I worked F1FHI on 70cm and then attemped to make contact with my half completed transverter with only milliwatts output. I worked him! A truly historic contact for me…later on 5th November 1987 I worked him again this time with the completed transverter and about 2 watts output into a home made 10 over 10 yagi.

UHF SWR / Power Meter

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This project was built to accompany my 23cm transverter so that I could align the output power and also trim my 10 over 10 slot fed yagi. The UHF reflectometer unit was purchased at the Leicester Rally from Birkitts at a cost of 50p! The UHF reflectometer works very well and I found it very useful. It works fine at 432Mhz and also 1296Mhz.

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