I've had some success fixing H-250/U and H-350/U handsets with bad earphone elements using this mini-speaker from Mouser Electronics:
https://www.mouser.com/ProductDetail/497-SM3604100-1

It is a little smaller than the original but with a bit of scrap foam padding it fits nicely.

It is a 100-ohm element so a better choice than a low impedance element.  It has had lots of level and good quality on the radios I've tested so far. 


Steve  WD8DAS

http://www.wd8das.net/
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