Rishworth Radio Convention

The radio convention yesterday was wonderful! Along with all the usual suspects around the market tables there were folks from further afield. Namely Rex Harper who delivered a fascinating lecture about PICaxes and their programming, see http://qrpme.com/. This really does seem like a rich area for electronics.

I participated in the Buildathon on the day, which involved constructing a 40metre radio receiver, ugly style under the guidance of pro's! (This project is publicised in Practical Wireless this month) :)

The build took about 3.5 hours in total and was working by the end of the session, receiving morse! I was well pleased.

Here is how it looks:



As I was browsing the isles of the market stalls in the rally I encountered a couple who were selling a book on crystal radio projects. Now I don't know if I have told you yet, but this is how I started getting into radio's. At least after breaking one or two when circuit bending and making music. I had encountered this easy radio to build on the internet. It uses only a crystal rock or a diode to rectify the signal of the electrical current, a tuning capaciter, and plenty of wire for ground, antenna and a coil. Oh and to hear you need a crystal ear piece.

So getting back to the rally. I had spent too long quite frankly looking through this book on crystal radio projects when the female of the couple said "you can have it for a pound" "oh, i guess i should buy it, I've spent so long looking at it!" Then the male counterpart joined in with questions about my job and then I suddenly developed into a "worthy cause". Very kind I think. And so for about £8 I ended up with a bundle of crystal radio parts to construct together and develop and share those skills.

So here is the crystal part.


This rock of galena is the detector. Using a piece of wire known as a "cat's whisker" to touch points on the crystal it is possible to pick up a radio signal.

Here is a suitable capacitor which is used to tune into the frequency of radio stations, this works along with the coil and crystal. Notice the fins that are carefully engineered not to touch each other as you turn the nob.


Then came these beauties


A real set of vintage headphones, 2000ohms (i think) that'll work wonders with a crystal set I am planning on building. They have a lovely leather strap and are in good working condition. The cord is fine for a vintage set of cans. Mmmm...


Once I am firmly on water I can get cracking with this project at my workstation. At the moment boxes lie upon boxes in the flat and there is no workstation to be seen - oh dear!