Alec, You are right. Radiometrix Ltd makes a lot of transmitters, receivers, transceivers, radio packet controllers (using PIC16C84), etc. in 418MHz for UK and 433.92MHz for Europe. http://www.radiometrix.co.uk/ regards Sabananthan Paramananthan (Saba) Radiometrix Ltd -----Original Message----- From: Alec Myers To: PICLIST@MITVMA.MIT.EDU Date: 21 November 1997 11:58 Subject: Re: Help ! - radio TX/rx for ultrasonic measurement >It's probably not worth designing your own RF circuits for something like >this. Lots of people offer hybrid modules and chips for TX/RX. They've done >all the hard work for you, and they're cheap too. > >Again, try (Hi, guys...how about a discount >on my next order...) I think they're made by a company called >Radiometrix, who might have a web-site of their own. There's a 400MHz band >AM transmitter that has two pins (V+, Gnd) that you can run off a PIC >output, and a hybrid carrier-detect AM receiver module selling for 2 pounds >sterling any-quantity. >They also do 27MHz stuff if you *must* use that band. > >and as Tjaart has just recently pointed out: > >>http://www.rfm.com/ sells some really nice one-chip-radios. > >Actually, if you're already putting ultrasonics on board each unit, why not >use it for both directions? That will double your time delay, and improve >your resolution. > >Alec > > > >=========================================================================== > ________ > / ______/ W5 Ltd. > ______ ______ _ / /___ > \ \ / \ / /____ \ 33 Sneath Avenue > \ \ / \ / __ / / London NW11 9AJ > \ \ / \ / / /_/ / United Kingdom > \ \/ /\ \/ \_____/ > \ / \ / Telephone +44 181 922 7778 > \ / \ / Fax +44 976 650 110 > \______/ \_______/ eMail mail@W5.co.uk > >Technology * Innovation * Design * Solutions