I just ordered my second SB-28 in preparation for my lighting kit... but until I order my stands/umbrellas/RF wireless, is there any way other than my SC-29 cord to use my SB-28's off-camera? I have also an SB-800 and a D70s... I just read the SB-28 manual, but it does not have any reference to a slave mode etc. on the SB-28. Thanks!