I have an old MFJ 1272B that I bought at a flea market. There have evidently been major changes in the design of units sold under this model number over the years. The manual that is currently available on the MFJ website is not useful for my older one.
These devices are configured for different radios and TNCs by putting jumpers on header pins. The manual I found on line is for a rev. 8 or 9 unit that has 2 sets of headers with a total of 96 pins, but the old unit I have has one header with 30 pins -- a totally different circuit. Can anyone point me to a schematic or manual for the older one? I suspect mine is a rev. 1 unit, there is no visible rev. number on the circuit board. 73, Al Woodhull, N1AW Amherst, MA
