Messages - Programme 3

"It's nice to see a programme like this as it shows that most things we use rely on all the fields in which we can study for them to work. I hope we can see many more programmes like this on TV."
Paul Weaver

"I think that your site is great! I use the flash version and it runs really smoothly. It is clear, interactive and very easy to navigate around. I am only 13 but love taking part in your online challenge which is great fun. I love watching the Rough Science programme, which really fascinates me. The web site accompanies it well with the explore the challenges section. Thank you very much for a great web site!"
Neil McFarlane

"I think the show is good and it helps revise for my exams."
Laurissa James

"I cannot believe that a group of "professional" people cannot build a kite! (Well done on the Tx and Rx.)"
John Herman

"Thank you for an inspired peice of telly. The ideas and methods used in Rough Science realy help to show how versatile the environment can be, after watching the latest instalment i feel an urge to go out and make stuff :-) There are not enough programmes of this quality available."
Al Jones

"Excellent, and informative."
John Massey

"I watched this week's Rough science. It was excellent, it was amazing how Kathy and Mike made a radio and transmiter, shame about "THE BIGGEST BONG EVER" clock. I really enjoy your Rough science programme."
Rowan Jones

"I think that considering there on an island they do the experiments very well and most work very well".
Thomas

"The best science based website on the net, bar none!!! After an 18 year career as an aircraft mechanic you think you're armed with all the technical knowhow......the challenge pushed me to rethink! Great TV, great web..... thanx."
Graham Welch

"I am enjoying the Rough Science programmes very much for I am from P.M. which is the hilly island east of Windward. Good effort from the team though I must say that the kite was just too heavy to fly from the green bamboo. I am enjoying the site and looking forward towards the next programme. I am learning a lot."
R Belmar

"I have really enjoyed this series of Rough Science and feel that you have done a great job of explaining the theory and making it exciting to watch. I found the radio challange very interesting but I would like to know how the coke tuned the radio! Is it becuase of its resistance or something else? Also, the microscope challange was amazing due to the quality of the image! Well done for making a programme that's fun to watch and very interesting at the same time! I hope you make another series!"
Tom Flannaghan

"Enjoying your programme: It's taking me back to the science and maths I did at school which I only vaguely grasped; and was never confident enough about to see their practical applicabilities. The context of your programmes gives them a fascination which helps my understanding. This website of yours is also very good."
Barry Johnson

"Saw your programme for the first time last night and will never miss it. Very interesting and informative."
Jan Lay

"When stupid TV shows are getting more and more popular and young people get less interested in sciences, emissions like yours would deserve a double award. Hope you will convince thousands of teenagers (and even adults) that science can be fun. Good luck."
Dimitri Pourbaix

"I found the crystal set very interesting and it brought back some very distant memories! In the early days of radio all radio transmiters were amplitude modulation (A.M.) but now it is mostly F.M. Would a crystal (diode) detect an FM signal? Was the local station used to "test" the receiver fortuitously using AM transmision? The Rough Science Web site is quite well presented in my opinion!"
John Camp

Jonathan Hare replies:
"Dear John,
Almost all the long, medium and short wave frequencies still use AM. So a simple crystal diode works a treat! Only the high frequency bands use FM (as FM takes up much more space on the radio spectrum, and there is 'more room at the top' so to speak). Our radio in RS2 was not tuned, this was so that the radio could pick up as much of the broad band spark transmission as possible. However, you can make crystal set radios tune and in this case it is possible to get them to pick up an FM transmission (if there happaned to be one transmiting on those frequencies). It works like this. To get the best signal from an AM station you need to tune to as near to the frequency of the station as possible. However if you tune in an FM station then you can hear the FM as a sort of AM station by slightly tunning off from the radio station. This is called slope detection and uses the fact that the radio becomes less sensitive as you tune away from the station and so as the frequency of the FM station moves around with the music (or programme) then the radio receives it as though it was a poor AM station. It's called slope detection because you make use of the slope of the changing sensitivity of the reciever when tunned close, but not precisely, to the station. This was how the old (USA) AM CB (citizen Band) radios used to be able to pick up the UK FM CB sets."
Jonathan

"Probably the best thing on TV. Extremely interesting. Very capable people involved, a real inspiration. Keep it up."
John Franklin