What Dave is trying to tell you is that you cannot raise the transmit line to 1 and expect that at the receivers output you will get a steady 1 for long time. This is NOT possible with the XTR module. It is possible with other tranceivers that are capable of direct RS-232 transmission.

RF is very different than direct cable link.

As for Manchester do a search and you shall find. Alot of infos. With 2 words works like this:

to send 1 0 0 0 0 0 0 1 the PIC should send the 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 1 0, that is the 1 is translated to 1 0 and the 0 to 0 1. So even if you send a steady 1 or 0 the XTR wil get a changing 1 0 or 0 1 at the input, cancelling out the DC component that a steady 1 or 0 carries.

Hope it makes some sense now.


Ioannis