To you probably could transmit through just a 50ohm resistor (I think wire
wound would work best).  The resistor will dissipate most of the power but
still radiate some energy.  If you are making a PCB you could use a trace as
an antenna.  Check out www.parallaxinc.com  they have a Tx/Rx pair that uses
a copper trace on the board for an antenna.

If all you are doing is transmitting the same code out I would use one of
the 8-pin PIC's.

Steve Keller


> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Nuno Pedrosa
> Sent: Thursday, June 25, 1998 4:30 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Radio Transmissions
>
>
> Thank you for the links!
> I've looked in Lynx, and they have small TX/RX pcb mounted that look
> really promising (and quite cheap, too. Enough to consider buying
> instead of building).
>
> Now I need to find the best way to work with them. They connect straight
> to the CPU, no problem with that, I think. But I need these to be
> really small. I hoped to be able to use vitually no antena, since I
> only need about 10-30 meters. But I never worked with RF. Don't know
> if this is possible.
>
> I intend to have a small transmiter just sending a code. And then, I
> want a receiver, getting this code. Since I'll be using a PIC in this
> receiver, I can do more than just checking the code. But that's
> basically what I need.
> In the transmitter it's probably easier to use also a PIC, instead of
> playing around with other logic...
>
> Any hints you could give me, I appreciate.
>
>   Thank you,
>   Nuno.
> --
>                                              _/^\_            __
> _____/\_________________________________oOOo__O-O__oOOo______/oo\____
>   /\/ /  Nuno Filipe Freitas Pedrosa                   __ /..\__/
>   \ \/\  mailto:Nuno.Pedrosa@oen.siemens.de           /`'\\__/-\ __
>    \/\ \ Tel. : 0049-89-72222342                      \__/  \__//@@\
> ___/ /\/_______________________________________________/OO\_..__\__/_
>    \/                                                  \__/
>