That's a great idea and the cost cannot be beat, but won't suit my application. My need is for anti-tampering of the receiver, that is, I don't want an average user to "follow the wires" to detect its location. I will research some of the transceiver module leads to hopefully find a cost effective solution. Thanks again, this list is just amazing in the breadth and availability of help. Bill Kichman Cornwall, PA USA -----Original Message----- From: William K. Borsum To: PICLIST@MITVMA.MIT.EDU Date: Tuesday, September 14, 1999 2:15 PM Subject: Re: RF transceivers >At 08:45 AM 9/14/99 -0400, you wrote: >>At 04:22 AM 09/14/1999 -0400, you wrote: >>>I need to transmit small bursts of repetetive digital data via RF (or >>>otherwise wireless) in an automotive type environment and receive same via >>>a separate receiver approximately 6 feet away. The method must be very >>>reliable and made so as not to cause or receive interference from sources >>>external to the circuit. >>>Can anybody provide some feedback as to how one might (as simply as >>>possible) design such a connection? >>>Any and all help is greatly appreciated. >> >> >>For short range (less than 10 or 12 feet), you can use poor mans fiber >>optic cable. It sounds bad at first, but it DOES WORK, and the best part is >>that you don't need special RF chips, antennas, it's interference free and >>can be contained in the existing enclosures. It's also RUGGED as Hell, >>easily concealed and cheap! >> >>Transmitters are simple LED's and receivers are photodiodes. The fiber >>optic cable is 20 to 40 pound test fish line, make sure you get the clear >>kind and make the ends with a razor sharp blade in a singe cut. >> > > >Motorolla used to make a really nice, inexpensive pair of >transmitter.receivers with the connector built in--used CHEAP plastic fiber >cable. >Mouse and digikey both are selling experimenters kits using these parts. >Great way to experiment. What they don't tell you is the Motorolla sold >off the business to someone else (Harris I think) and they are still being >made, but hard to find. Contact me off list if you need a current source >and I'll see what I can dig up. >Suggest getting one of the kits first though. > >Kelly > > >William K. Borsum, P.E. -- OEM Dataloggers and Instrumentation Systems > & >