simple transmitter reciever for 40 meters

[engineer jefry]

Hi
i am new here , but i have a question .
any one can help me contact me please
i want to make circuit that transmit for a short range ,and a reciever to capture this signal .
the signal transmitted is not a control signal it is just a field that ensure that the reciever is in the range if the reciever go out of the range of the transmitter a relay ring a bell
i wish any one can help me

 

[stevez]

You will find numerous designs for transmitters and receivers for the 40 meter amateur band in amateur radio publications. Much of what is published cannot be viewed for free via the internet as it is in hardcopy form or otherwise protected by copyright. I am sure there is some information available for free, via the internet. You might try amateur QRP as search terms. QRP is hamspeak for low power and many QRPers have published good stuff on their websites.

Tuna Tin 2 is the name for a small 40 meter CW transmitter than can be constructed from fairly common parts. If you google enough you'll find simple companion receivers.

 

[mneary]

Modulation type on 40M is very limited depending on the class of your license. 40M is also very likely to carry signals to/from distant locations. (keyword: propagation) The 1/2 wavelength antenna is 65 feet long, meaning that it's hard to make the antenna very portable.

The best site I've seen for QRP construction is **broken link removed**.

Please get an amateur radio license before you begin transmitting on the HAM bands.