As I recall (from the dim, dark past), selecting ANT will park the pointer on some aircraft (sometimes useful if you have a faulty antenna and the ADF pointer is wandering aimlessly around the dial distracting the hell out of you).
On aircraft with MCDU tuning of ADF's you may be able to select "ANT" by typing "A" after the frequency.
Rgds.. .Q.
P.S. By the way, "411A", didn't the 707's have a LOOP selection also(Can't quite remember what its funtion was tho').