UHF-Satcom.com - Yaesu FT897 band data output (17/02/2012 22:31:07 -0000)
On the rear panel of the FT897 is a 8 pin mini-din plug that can be software configured to connect to a linear amp, a computer or an antenna tuner. In this application, the option on menu 20 must be set to "linear".
The reason the band switching outputs were examined was to find a simple way of combining the antenna's such that automatic operation across all bands would be permitted without manually switching antennas. Diplexers were looked at but none could be found that satisfied the design requirements.
On the 8 pin mini-din, the band data connections, A,B,C and D have TTL compatible outputs, that is low is 0V and high is 5V.
The picture below shows the details of the band data outputs, along with the corresponding frequency ranges.