Take a look at super-regenerative receivers.
I'mthinking of  a similar project at the moment & am considering a simple
regen circuit. The advantages are that I'm hoping to be able to use the
same components for both TX & RX and possibly a single port pin (changed
between an output and an input).
"Electronics & Wireless World" had an article on superregens a month or so
back & the circuits given appear to work OK at 70MHz or so - I've just got
to get the right transistors for UHF operation.

The disadvantage is that unless you buy a resonator to control the
frequency it could be difficult to tune & temperature drift could be a
problem - and with a resonator the bit rate is somewhat limited.
If you're interested I'll try and draw a rough circuit. - Probably only one
or two transistors but there could be a software requirement to process the
received signal unless additional external components are added.

Richard P




Folks, I need a transmitter, receiver to integrate in a product, where the
range required is minimal (not more that 10 feet). Also, the bandwidth
requirement is exremely minimal; a few bytes to be sent every few minutes.

The criticality is more to do with the economics involved. I cant therefore
think of using pre-assembled rf modules like the Ming series.

Considering the modest range and bandwidth requirements, I am tempted to
use my own receiver and transmitter, integrated on the PIC PCB, for the
project.

Are there any 300 MHz or 418 MHz circuits on the internet to do this? I
have the circuit for the transmitter, which is extremely simple in design,
and I'm hoping someone can help with the receiver schematic.

Thanks and regards,

Anand Dhuru

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body