GE P-9011 Speaker Issues

[Celt]

If it's actually a field coil speaker, the circuit may need an inductor to replace the coil when replaced with a PM speaker. Might check the DCR of the speaker too. Speaker impedances on those old transistor radios were all over the place back then. I wonder if the existing speaker is actually an output transformer and driver built together? Many of the old transistor radios used OT's.

[YamahaFreak]

Originally Posted by Celt

If it's actually a field coil speaker, the circuit may need an inductor to replace the coil when replaced with a PM speaker. Might check the DCR of the speaker too. Speaker impedances on those old transistor radios were all over the place back then. I wonder if the existing speaker is actually an output transformer and driver built together? Many of the old transistor radios used OT's.

That's probably what it is, there are three leads to the speaker rather than the usual two. I'm almost certain that there's nothing else wrong with the speaker other than those teeny iron shavings inside. The radio has great reception and is nice and strong, only the speaker has issues.

[Don Lindsly]

It is a speaker and output transformer combined. As the loose transformer lamination moves, it modulates the speaker cone. GE also used that concept on some early paging receivers. The communication engineers took the idea from the consumer guys as a cost and weight measure.

Try passing the entire speaker assembly through a color TV degaussing coil or some other strong AC field while shaking it, to release the filings. You may not even need to remove it from the radio.

[YamahaFreak]

Originally Posted by Don Lindsly

It is a speaker and output transformer combined. As the loose transformer lamination moves, it modulates the speaker cone. GE also used that concept on some early paging receivers. The communication engineers took the idea from the consumer guys as a cost and weight measure.

Try passing the entire speaker assembly through a color TV degaussing coil or some other strong AC field while shaking it, to release the filings. You may not even need to remove it from the radio.

Do you think a bulk reel tape eraser would work?