Home page Miscellaneous Projects Built mainly from my "Junk Box".
PW Marchwood 13.8V 30A Power Supply
Every radio amateur need a good shack power supply and as the ones I had looked at in emporia and rallies were quite expensive I decided to build my own mostly from my junk box.
The circuit used was the PW Marchwood 30Amp by G4JET and a two part article featured in Practical Wireless June 1983 with a complete parts list and build instructions. It was a fairly easy project to build and the only job I couldn't do myself was the PCB which a friend kindly made for me. The majority of bits were from the junk box or left over new items from previous projects. some of the bits are an overkill but that's what I had and used, Below are some photos of the completed supply which I built in the mid 80's and still in trouble free use today. Below are a few photos of the PSU with the top cover removed which gives and idea of the layout.
RF PEP Power Meter
After being given the remains of a Bird Panel Wattmeter by a friend I decided to put it into an enclosure and have another meter to monitor RF input to my VHF Linear Amplifier. The remains consisted of the meter, the RF sensing unit and the attaching cable assembly so all I had to do was to find a suitable box in which to house my project. In the junk box I found a used die cast box of near suitable dimensions with the odd hole here and there but managed to miss the holes or open them up to accommodate the meter and switch etc. Also I had an old LAN TECHNOLOGY PEP board lying around, this was refurbished and used in the project.
Basically all that was needed was careful marking out cutting and filing the box until the bits were a snug fit, Once that was done the bits were removed to allow the box to be painted before final assembly. After painting the box all that remained was to final fit the parts for adjustment and testing, One minor issue was the depth the box was quite narrow making it unstable in the vertical position so an extended rear foot was added and this cured the problem.
The PEP board was tested and calibrated and the meter put into service, Although it looks a bit odd it's fit for function and is a lot cheaper than a true "Bird" version, the PEP board is powered my a 9v battery or an external power source. Below are a few photos of the project. The wattmeter works perfectly and is a welcome addition to my shack.