Ali Sajjad

well after a long time i came back ... Nigel i visited your website... and i m seriuosly thinking to take some advices from you.. not only regarding electronics.. but for physical fitness as well :P ...

Anyway.... i wish to make a remote control based on radio waves... which would work within a circle of 1 Km... i have not selected a frequency yet.. but it would be in the range of 40 - 70 Mhz..... the remote control shall be for controlling of 8 devices (TURN ON - TURN OFF, MOMENATRY ON ).

I hope u would give some good ideas and help me to select the better type of data coding... i thought of DTMF b'caz its simple.

I like Nigel, but that does not mean that no one else could give his/her ideas....


- Ali Sajjad

Nigel Goodwin

I think your first move is to find out what you are allowed to do in your country, you haven't filled your location in, so we don't have any idea where you might be.

Most countries have some kind of restrictions on radio transmissions, the UK's are particularly strict - however, there are a few licence free areas, but with various restrictions, particularly as regards power and aerial systems. Many manufacturers make cheap transmitter and receiver modules to comply with the licence free regulations, these are probably by far the best way to go. But first you need to find out what you can use!.

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Crofty

Hi.. Try here first >> http://www.lprs.co.uk/main/product.i...p?productid=24 We used this TX with the matched narrow band RX, for a security product. Distances over 2km have been achieved with that pair. Note, much depends on antenna efficiency and terrain Narrow-Band appears to be the key.

Note.. not in 40-70MHz band, but ready made and legal, not to mention Tiny. Also should cover your range.

Steve