I guess the first question is do you have any control cables?
There are a number of control heads that will play with the Delta and Delta-SX radios. The bottom
selection is the S550 head, then the S950, S990 and last the S825 head. The S950 / S990 and the
S825 heads all require some sort of programming to make them play the way you want. The S550
head plays by itself and requires no programming.
As to a source of these heads, Ebay, some of the Yahoo chat groups. There are a number of
GE type groups on Yahoo. The best ones for you to try are GE and GE_DELTA_RANGER. There
is also another group web site www.radioinfoboard.com that should provide a GE/Erricson
selection. Many of these sites require you to register in order to originate or reply to messages.