Here is a slick modification from WB1ASH on how to make your MFJ-1270 talk
at 19.2k baud through its RS232 port.

Connect the common side of sw2 (the terminal baud rate switch, the common
side is in the middle with all of the pins connected together), connect
them to U1 pin 10.

turn switches 1-5 off (0)

your now at a terminal baud rate of 19.2k.
It has been tested it both with a terminal and with a Pac-com Tiny-2 in the
net/rom configuration and seems to work great.