Perhaps you could switch to RS485 or convert from RS232 to RS485 then from
RS485 back to RS232 on the other end.  I think the MAX485 is the RS485
equivalent of the MAX232.  There's quite a bit of info on the Net regarding
RS485.

Eric

On Saturday, May 15, 1999 1:55 PM, Robert Mellgren
[SMTP:robert.mellgren@VALHALLA.ORNSKOLDSVIK.COM] wrote:
> hi there i seem to recall that RS232 transmissions should be done over
short
> cables. since there are only -3/+3v levels, is this true.
>
> Since this transfer shall travel from 0.3 M - 200M i may need a potent
> voltage level and a good shielding.
>
> Which do you think is the best way too boost such a signal, should i
boost
> it straight from the output pin from the pic, with the help of a NPN
> transistor, that drains say.. 12v-24v then convert that level of voltage
> back to TTL with a 7805, is the 7805 fast enough? we are after all
talking
> 1200 baud here, i do not seem to find a datasheet that describes this.
>
> Or make some sort of optic transmission, ( which is less cheap ), via
optic
> cables, the positive side of this is that it wont be affected by
> distrubances.
>
> Hit me with some of your experiences in this matter, It would be be most
> appreciated.
>
>
> Greets
> Robert
>
> input...input... i need.. input...