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Here's a subject that gets me excited.
The Telsen Electric Company Ltd, Aston, Birmingham.
I have a collection of Wirelesses and other products made by them.
Incidentally, most of the stuff that is on the internet was put there by me.
But, does anyone have any personal memories or connections with this long extinct company?
OK Girls, calm down,
If Phil had as many servants when he was a kid as the rest of us he would have moved to Yardley or Sheldon, as it is he waited until he was super rich and skipped over us to Chelmsley Wood, I mean Solihull.
Crystal sets use only the power of the radiated wave, no batteries, no winders, no external power at all.
As Phil says, you made your own, from a few basic components and a few lengths of wire. The audio came from high impedance headphones. You can still do this today. If you want more audio output power then you need an amplifier and that will require a power source.
When I was ten I made one with a single transistor amplifier and put a small speaker under my pillow, it ran for about 2 years on a single cycle lamp battery. By my time the whisker and crystal were replaced by a Germanium diode so there was no need for twiddling the whisker to get the optimum rectification of the incoming wave.
The Telsen sets don't use a Cats Whisker and Crystal detector, they use thermionic valves and mains power.
They are pieces of furniture with state of the art radio receivers built in.
Telsen also made kits for people to build wireless receivers (radios) at home. To this end they made a whole range of components suitable for fixing to a basebord, I have a small collection of these items and hope to eventually get around to building a working set.
Telsen also produced a magazine for the home constructor, it ran to six editions during 1933/34. I have all six magazines, along with the blueprints they produced to show the exact layout of the components for their projects.
Perhaps I should mention that commercially produced crystal sets were also produced and are still to be seen fetching good prices at auctions.
They also promoted a good market in aerials, earthing kits, cats whisker detectors and headphones.
As can be seen in Phil's picture, the so called cats whisker crystal detectors comprised a piece of wire (the whisker) and a Galena crystal. In order to avoid contamnation of their surface the crystals were supplied in small tins which are now very collectable.
Army surplus and ex BBC headphones were ideal, such as magnetic coil and disc construction, provided they were high impedance types. These gave high volumes at low voltages.
A long wire was required as an aerial, to gather sufficient signal to get something audible, along with a good connection to earth to encourage more of the radio signal into the aerial. In my experience the power of the radio signals in Yardley meant the length of wire could be fairly short.
Longer wires brought in more distant stations but that wasn't a good thing with a simple receiver because they would be heard on top of one another. More complex receivers are then required to provide better selectivity so that the stations on different frequencies can be kept apart.
These days the waves are so congested with high power stations that a simple crytal set is overwhelmed and many stations can be heard at once.
Even the best of us might shy away from building blocks of flats on our ownsome.
Most of my mates would have wanted to build a pub first and that would have been that.