Projects

For a while I operated on 23cm with just my IC-910 with it’s UX-910 module, this was only 10w.  Rather luckily  John G4BAO lives local and had designed and published a nice 45w LDMOS 23cm amplifier.  It was quite easy to go put a pair together using a pair of W6PQL hybrid combiners. To start with I had the pair on a flat 19” rack which was rather exposed and didn’t have all parts integrated such as the PSU.  I had planned to box everything [...]

  I decided to build a new rotator controller to replace my Yaesu G400RC controller (but my design was made to work with virtually any rotator) to give me additional futures beyond the sole analogue position feedback of the G-400RC. I wanted the new design to be digital, have integrated PC control, hands off operation (pick your direction and then sit back) and have different modes of operation depending upon current operation style.  I had previously built a rotator PC interface but not a full [...]

One of the aspects of amateur radio I enjoy is EME.  When I was active on 2m (144MHz) EME I built my own elevation system using a jack-arm but I then needed a way to feedback the angle.  I tried many ways in the past such as potentiometers then Sam G4DDK introduced me to the MXD2125 dual axis accelerometer device.   This can be used, along with gravity, to measure tilt, the angle vs down.  Comparing both X & Y axis outputs the resolution can [...]

I started using an LVB Tracker by G6LVB (also of FunCube Dongle fame) to control my Yeasu G400RC and KR-5400 rotators which have my directional antennas on them – The G400RC + homebrew jack-arm elevation was mainly for EME and the KR5400 was for satellite work.  I had to built an elevation feedback circuit, I chose a MXD5125 for this but I found I still lacked some of the features of more advanced rotators and with the LVB Tracker being controlled by serial using the [...]

After the 2011 Camb-Hams DX’Pedition to Arran and using the Discovery 64 on 6m and making some good contacts on it I decided to bite the bullet and go buy a decent 6m Amplifier. I have been thinking of getting an amplifier for HF and 6m for a while but didn’t want to have 2 extra amplifiers in the shack, one for HF and one for 6m (50MHz).  There are a few options about for a combined HF + 6m amplifier and luckily a Yaesu [...]

I bought a Small Wonder Labs PSK-20 kit a few years ago when I was dabbling with HF data modes.  The PSK-20 is, from the PSK-20 manual “[a] transceiver on a single PC-board design measuring 4.6" x 5.27" (12 x 13.4 cm). It is functionally a crystal-controlled SSB transceiver with slightly wider than normal IF passband characteristics. It covers the range of 14.070 to 14.074 Mhz.”. It comes in kit form and unfortunately is no longer available, however a note on the Small Wonder Labs [...]

My 2m station includes a masthead preamp, a 2 x 4cx250 linear and the IC-910. In order not to blow up the preamp I needed to get a sequencer, me being me I decided to design and build one, total cost with the box was around £10. This is a very simple design and uses a PICAXE-08M for the control as it supports 5 input/outputs. All I needed was 1 input (PTT) and 3 outputs, preamp, TX Amp and radio. The preamp, TX Amp and [...]

A band I’m interested in is 4m which in the UK we are allowed 70MHz to 70.5MHz.  I’m mainly interested in the MS and ‘E’ capability of this band but very few commercial SSB radios have 4m built in so the easiest way is to transvert, usually from 28MHz with a 42MHz oscillator to get 70MHz.  For those unfamiliar with transverting this mixing will produce 2 frequencies, one 42MHz above and one 42MHz below, if we take 70.2MHz this means an unwanted one at 112.2MHz [...]

This project has been an idea of mine for a while and it took me a little while to get the oomph to start on it. Start I did, slowly at first then once in the swing of it I finished it in a few days. The project outline was to replace my current homebrew isolated data interfaces which only had a single serial port for CI-V and PTT plus audio in and out isolation for a new fully USB version which has 2 serial [...]

This project is for a PIC based audio and PTT controller which has a single headset and foot-switch which can connect to 3 different ham radios at once for a single operator to simultaneously receive or transmit on any combination of the radios. I’ve been working on this project for a while.  I like to monitor more than one radio at a time but found it annoying having multiple speakers.  Also for transmitting I didn’t like the fact I had to have multiple mics and [...]