[Premium-Rx] AEG Telefunken E1800 V/3 Center Tuning function enable

[An interested surfer]

I learned that 2  1710 modules are needed to enable this, but they seem to
come with different configs and connectors. Looking for an old post or new
info on which boards are needed to enable the center tuning indicator
function, not necessarily RTTY, but basic AM,SSB, maybe CW. I am also
interested in finding one of these receivers to compliment my amateur radio
gear for general monitoring. KE2BP