1950s 1959 radio advice needed

[1969cadillac]

Hello ! i have a 1959 radio here from a series 62 coupe that i need to sell for a friend who used to own one of these cars . I dont know what radios were available this year ..but this one is an AM only with self seeking device. I would like to power the device up and connect a speaker to see if it is working correctly BUT i am reluctant to apply power to something that has not been powered up for probably over 20 years as i do not want to damage the unit! I have NO wiring harness for it.... it appears to have a square 4 pin plug at the bottom of the unit and a round 3 pin plug on the rear of the unit ... as well as the antenna connection of course. Q. what is the ohms rating of the speaker that i need to connect? If anyone has a connection wiring diagram for this unit it would be appreciated! Model is 7272505. Thanks , Murray Mules 

[bcroe]

Your radio requires an output impedance matching
transformer that is mounted on the speaker and
plugs in.  Without it and that 4 pin plug the
radio cannot be operated properly.  Another 4
prong controls the antenna.  Bruce Roe

[Cadillac Jack 82]

Make sure you have at least an 8 ohm or 10 ohm speaker connected or you'll fry her out.  If you wanna sell it my buddy with a 59 sedan deville would love it.

[alzink]

I have a restored one out of a 1955 (AM wonderbar) if anyone is interested

Al

[Cadillac Jack 82]

1955 radio will not fit a 59.  Completely different.