Battery-Free Crank Radio Speaker Repair

I bought my battery-free crank radio second-hand for two pounds. When I installed some new batteries, I noticed that it was not very loud even at full volume, so I decided to investigate. I connected a pair of headphones to the socket and that was very loud, therefore there was something wrong with the internal loudspeaker.

The loudspeaker was attached to the plastic case with glue and I carefully removed it. I noticed that the paper cone was in the out position and the coil was outside the magnetic channel. After a little realigning, the cone went back in and the sound was loud again. I considered myself lucky and installed the speaker back in its place. I do not know if it is a common fault, but it might help someone with a similar issue.

The sound quality from this 0.5-watt speaker is good and it is ear splitting loud. This is probably due to the excellent Sony radio IC that also has a built-in power amplifier. The IC is able to produce 0.5 W output through 8-Ω load impedance, when the supply voltage (Vcc) is 6 V.

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