The 155-0109 is a Tek-made trigger chip good to 350 MHz. It was made in two versions: the 155-0109-00 and 155-0109-01. It is used in these plugins: 7S14, 7B80, 7B85, 7B87, 7B90P, SC502.
155-0109-01 block diagram
155-0109 in 7S14 trigger
