Antennas in transmitter

In the DC16II & DC 24 you got 4 antennas for the 2.4Ghz , are they also in use with one receiver ( as back-up ore Freq hopping)) ore only functional with 2 2,4 Ghz receivers ?? ( now using Ds12 with 900 back-up in some models)

AFAIK Yes, they are always in use, also when using only one Receiver.

Also the DC/DS14 is using all antennas if the 2 HF mode is unlocked.

Regards
Nicolas