Revophone 349 crystal set (1923)

 

It's a bit complicated this one, lol I found the empty Revophone box in one buy and the chassis was found in another buy. The twin tapped coils had become highly tangled and I spent quite some time putting that right. The brass name plaque came from underneath the radio, so I moved it to the top, the chassis was an unknown manufacturer but may be a Revophone of another model, still confused.

The tangled mess before I tackled it

Keeping the old look I cleaned-up the crystal housing tube, re-made the cat's whisker and painstakingly checked the continuity between all the wire switch terminals, of which there was many. The nice thing about lidded 20s radios is that the Ebonite is protected from the Sun's rays that turn it a brown colour with age. 

The circuit here, as with most Crystal Sets is very simple and needs no power source, all the energy is in the airwaves of local transmitters, usually b/w 50-75 miles away using high power is all it needs. In fact the power is that high, I read once the a cottage near a transmitter site was draining the current for the transmissions using large loop of wire in his loft, it was enough to power his lighting. He was found out and fined, lol Anyway back to the radio ... 4 terminals are for aerial, earth and headphones, a long length of will is needed for an aerial as indicated by the original label in the lid. The layout is upside down on that diagram, 'cus it was another model.

The factory was very large and employed many people from the local Tipton, West Midlands area during it's hey days of the 1920s and 30's. They made cookers, fires and even street lighting under the name Revo, when the radios were being built they offered a crystal set the size of a tobacco tin at a bargain price of 5 shillings and 6 pence. The site was located along side the Birmingham Canal for ease of shipping in those early horse drawn days of the industrial revolution. More can be found here:- Tipton History site