This one was a lot of fun. This valve receiver was constructed in 1988 in the traditional way, i.e. an aluminium front panel and chassis. A mains isolating transformer and rectifier was also required, this was built in a separate box to keep interference away from the radio. I discovered (perhaps unsurprisingly) that if you put the transformer next to the radio all you could hear was a nasty hum! The transformer is an old-fashioned 250V secondary valve power supply type, which also has a 6.3V winding for the valve heaters. (Click the photographs for larger versions).

Circuit Diagrams

Well, I learnt all about valves, or so I thought, and came up with this single valve design, which I showed to my Dad as he was the real expert on valve radios. He recommended a different design for many reasons, and I learnt a tremendous amount from our discussions about the improved design. My idea was as shown far right (below, click for larger image).

Below left is my Dad's modified design, which I built from. I am not sure if there were any further modifications during the construction, there probably were because that's the way these things generally go. But anyhow, this circuit is fairly close to the final, of that I am certain.