how to revive a first generation Olympic 447 portable transistor radio

this radio is housed in a hinged split case. the hinge is at the bottom and the radio splits open right along the center inline with the knobs. it's easy to open so you can replace the batteries. no tools are needed to get inside.

pic 2 is of the radio opened up. the radio runs off 9vdc. it has two battery connectors but both are wired in parallel. now is a good time to see if your radio works at all. do not exceed 9v input to the radio. you risk damaging some VERY hard to find transistors. this radio will power up with 6v-9v. you can use a regulated power supply or a 9v battery and alligator clips.

look at the old battery connectors coming out of the radio. on the connector at the end of the cable, the terminal at the very end (not where the wires come in to the connector) is the positive terminal. apply power, turn the radio on at full volume, and tune around. get anything? any sign of life is good. it's possible your radio may play loud, in that case back down on the volume control.

your radio should have a pictorial diagram inside like the one in pic 3. it may be of help here. on a humorous note, the pictorial diagram shows the transistors in transistor sockets. the actual production model just re-used the tube sockets.

are you getting lots of hash and noise but nothing intelligible? is the radio right next to a computer or lithium battery charger? those two things can generate plenty of RF noise on an AM radio. relocate the radio and try again or shut off the possible noise sources. try again.

get anything now? if your radio picks up anything, that's a good sign. tinny, weak, or distorted audio we can fix. if your radio is totally dead you may need to do some simple checks.

take a multimeter and check for continuity from the positive battery terminal to the metal radio chassis. the radio should be switched on for this test. like many early transistor radios, this one uses positive ground. you should have continuity. if you don't, you need to find out why.

look at the volume control. the power switch is built in. it's got two terminals grouped together. those are the power switch terminals. check for continuity here. you should have continuity when the radio is switched on. if you don't, your power switch is bad and that would cause a dead radio.

if you have a totally dead radio, there is still hope but you may want to consider the fact that your radio may have issues beyond the scope of this instructable.

next up, we get inside.

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