ETRONIC ECS2231

Advert from March 1951 Link to larger view [177K]

Etronic's swan-song; this is their most expensive television and indeed was their only projection television. Released in late 1950, 18 months before the company went out of business, I doubt many were made, this one bearing the serial number 00183. They must have anticipated a lot more to be built as after their demise a number of surplus stores were offering the cabinets for the budding amatuer electronics enthusiast to build into a radiogram.

For a small company to produce such a projection set led me to think they used a Plessey chassis, but no, this is Etronic's on design. Component supplies must have been easier now, as unlike the mix of manufacturer's valves found in their earlier HV203 model this chassis uses all Mullard valves.

The set was pre-tuned to the rquired channel (London, Birmingham, and later Holme Moss). Although many manufacturers had made their sets tunable, this set had two RF amplifiers prior to the frequency changer which would make it difficult to make tuneable. The frequency changer is followed by two I.F. stages; in my book this makes this set 50% superhet, 50% T.R.F. ! As for the rest of the circuit, it seems fairly standard in design with perhaps the exception of the focus controls. Yes, controls ! The focus coil is simply in line with the HT circuit - standard practice - but is bridged by two focus rehostats, one "coarse" and one "fine" focus. Perhaps the current was a little unpredictable !?