yesterday i bought a johnson messenger 2 at a estate sale for 1 dollar but it has no user manual. i downloaded a shop manual but cannot find a user manual . how do i hook up a speaker to the unit? in the back of the radio is a ac plug and above this is another round plug. the only no.s i can find is a serial no.0126202 and the fcc lic taped to the side of the radio with mr smick's call sign of kfi1504 that expired in 10-3-1967 any help would be very appriciated. dad used to be in radio repair in the military but he hasn't done anything for the last 30 yrs so he is not much help.