Phil's Valve Radio Site

Welcome to this website featuring a pastime hobby, based about my home built Vintage Radios. As well as walking and cycling I have been into Electronics for the past 50 years and I built my first working Radio from a Philips Electronic Kit, A popular educational Christmas toy present during my childhood days of the 1960s and early seventies. The pictures starting from the top left, in the order of 1 to 2 is a battery operated Short Wave Receiver built on Christmas day in 1977 and is still my most treasured Christmas presents. It was purchased from Tandy, which in its heyday was one of the UK leading high street stores for electronic gadgets until it ceased trading during the late 1990s. Picture 3 is a 1950s Mullard design based on there 20 watt push pull designed for high quality Hi Fi reproduction a bit before the transistor really caught up with us. The original design used the valve line up in the following order. GZ34 Rectifier. 2 EL34 Output valves. ECC83 Phase splitter and EF86 Input valve. This design of mine was built from a Kit purchased from Maplin Electronics which was a popular recommended City and Internet retail electronic store until it went into administration and stopped trading in 2018. It is basically the same circuitry with slight modifications. A solid state bridge rectifier replaces the GZ34 in the smoothing circuit. The pictures in the order of 4 and 5 feature my complete home built superhet valve radio. The circuitry was taken from some of my old electronic magazines and books. The valve line up is as follows. ECF82 is for the frequency changer and local oscillator. 2 EF80 are used for the Intermittent Frequency IF Amplifier. EBC81 is used for the diode detector and audio input stage. EL84 is used for the Output valve to drive a loudspeaker. The Radio covers the Short Wave bands between 1.6 to 30 Megahertz and the standard Medium AM broadcast band. The Short Wave bands give me many hours of pleasure but sadly because of the internet boom there are not many Shortwave broadcast stations around as international stations have moved onto the new digital platform. Also all BBC and national radio stations moving on to FM the Medium Wave band has limited choice. The pictures in the order of 6 to 11 feature my home built, valve portable Hi Fi or so called Hi Fi system to some. The reason I mention is because it uses the Mullard range of valve amplifiers, designed for a output power of only 2 watts, consisting of the ECL82 Triode Pentode I call the super micro chip of the 1950s because it was used for the output stage in many radios, televisions and portable Record Players of that period. The 7th picture features the back inside of this design and right of the picture is a stereo amplifier with solid state rectification and 2 ECL82 valves. The left inside of this picture is a combined FM tuner, Tone control and pre amplifier bundled with a BSR Goldring turntable for the reproduction of records. The FM tuner is also a superhet and uses pulse counting technology for the IF to save winding coils and although a Mono tuner it gives excellent Hi Fi Reproduction on Local and National radio stations. The valve line up is ECF80 frequency changer with a grounded grid RF stage. 3 EF80 are used for the IF amplifier and limiter. The FM detector is a 6AL5 Double Diode, wired as a voltage doubler or correctly known as a diode pump circuit. The Preamplifier is a simple Double triode ECC83 affair for both stereo channels.