In a stock SB-102, the RF output connector is an RCA phono jack. Many of these rigs have been modified to replace the RCA phono jack with an SO-239 coax connector. Take a look at your specific rig to confirm what kind of connector is needed.
Just finished building a RCA / RG-58 cable for tcvr to dummy load, and a RG-213 cable to connect the amp to DL. Dang that Belden RG- 213 is over $2.00 a foot here.