Will a cats whisker radio still work?

[ericmark]

I remember making one as a boy, yellow bits in coal made a good diode, but are there any transmitters left running?

 

[Johntheo5]

In the late 50s, we used to wire a Germanium Diode? across the terminals of a old/surplus earphone then connect it to a aerial wire (barbed wire or the like) and pick up the local radio radio (only one at that time) station, no battery required.

 

[BS3036]

In the next year or so, the BBC will stop all am broadcasting. Most of Europe has done the same. Only the USA have a lot of stations, and as I understand it a rule that cars still be equipped with it as it is used for national emergency transmitters. There may well be LPAM or Community Radio stations available here to still be able to demonstrate crystal sets. Or you can cheat and use your own low power am transmitter, as so many old broadcast radio enthusiasts use to make their refurbished sets actually do something.

 

[ericmark]

I know as a lad, there was a SW on the radio, and I could tune into all sorts, but in latter life, found I needed a beat frequency oscillator (BFO) to get stations, and so the short wave listening as a hobby died out.

There are still some, I have sent out QSL cards to them, but not like there were.

It started when my wife asked daughter to bring some toilet rolls and Whiskers tomorrow when she visits, and I remembered the old crystal sets. As said needed a Germanium Diode the Silicon type would not work. But one could use the yellow bits in the coal, not seen the yellow bits for years, still loads of coal where I work, but not seen yellow streaks in it.

I have not seen high impedance ear pieces for sale either, and to find a variable capactor think unlikely today, yes I know ferrite rod in the coil can also be used to tune in, but when I was a lad you could even buy a kit with instructions.

Latter Sir Clive Sinclair sold kits, which I would make up and sell at school, until the teachers realised not that many children needed deaf aids. Who remembers the Micro 6?

 

[BS3036]

It seems that 'modern' crystal sets include a matching transformer so you can use low impedance headphones.
(BTW don't forget to book your MOT; they get busy this time of year, because of Covid, and you may have trouble with your front exhaust section!)

 

[morqthana]

I know as a lad, there was a SW on the radio, and I could tune into all sorts, but in latter life, found I needed a beat frequency oscillator (BFO) to get stations, and so the short wave listening as a hobby died out.

Vintage Panasonic RF-2200, or Grundig Yacht Boy?

Sangean ATS-909X?

 

[ebee]

Diodes AO90 or AO91 some High impedance headphones (or a crystal earphone) a coil of wire, a high ariel wire and an earth and you had a good chance and all free no batteries.

Those were the days, build yer own morse key too for contact between houses as kids too.

 

[flameport]

I have not seen high impedance ear pieces for sale either,

They still exist, https://cpc.farnell.com/soundlab/a014/mono-crystal-earpiece/dp/AV29544

 

[endecotp]

Diodes AO90 or AO91 some High impedance headphones (or a crystal earphone) a coil of wire, a high ariel wire and an earth

...and a capacitor. "One over two pi root L C, is the resonant frequency"!

If you're going to try it, get away from electrical noise as much as possible. My only attempt, I picked up mostly 50 Hz and whatever odd frequencies my 'scope was giving off.

 

[ebee]

I actually found that a variable cap was not required when using high impedance dynamic headphones for some reason, (sliding the coil on a ferite rod gave some tuning), perhaps the capacitence of the arial system (first floor bedroom windows exceeding 100 metres length and L shape in this case picked up (Radio 4 pretty well enough to give low audible volume over 4 sets of headphones - using each headphone set as a "telephone" one piece to your ear and the other piece to your mouth enabled a 4 way conversation) , no batteries involved, the two extreme headphone sets lightly connnected to a waterpipe.

One of the experiments involved a redundant valve radio set and the coil was an absolute joy to use.
A few inches diameter wound coil with serveral tap off points to vary the coil and the last portion of the coil was wound on a smaller diameter and could be rotated thru 360 degrees inside the main coil as a series winding giving infinately variable coil for tuning and yes the variable cap did trim the tuning a bit .
TV ariels back then were all a big "H" or a big "X" sort of thing fastening to the first floor chimney (the "BBC 2 ariel" was not yet invented).
great fun for a bunch of 13 year olds using salvaged lengths of every kind of wire we could scrounge and all of the joints merely twisted together.
If you needed to make a call on a proper telephone youd find the nearest GPO telephone box and queue for it then insert coins and press button A and botton B when appropriate or find one of the 1 in 20 homes that actually had a GPO telephone in their homes.

 

[spile]

TV ariels back then were all a big "H" or a big "X" sort of thing fastening to the first floor chimney

50MHz BBC and 220MHz ITV respectively from memory