Damn... What's weird is that I've never heard this rig mentioned in the realm of commercial, military, and gov, rigs. Well, if there is documentation on this, it's got to be a thick binder-like book. Question is, did anyone ever scan it to .PDF?
https://www.fenu-radio.ch/AEG_Telefunken-E1800-3-en.htm and
http://www.classicbroadcast.de/downloads/telefunken_E1800.pdf Some nice looks and spec's here, but no documentation of its guts. This, will give me something to quiz about to those that I know that brag about having Harris, Drake, Collins, Watkins-Johnson, Standard, etc., rigs in their collection. Someone's got to have documentation out there. Here's this page, with German language review.
http://alerter.co/e1800a_doc.htm Even this site says that technical DOC is damn hard to find. If anything, THANKS for the subject for me to kick-around when I'm QSO'ing on Amateur Radio.