"Joe" wrote in message
...
I just managed to get hold of unbuilt Heathkit alarm clock GC-1107.
The electrolytics were dry and the speaker is shot.
Finding replacement caps was easy, but does anyone here know the impedance of
this 2,5" speaker?
Is it "normal" 8 ohms or something more exotic?

-Jan

The speaker is used as the collector load for am MPSA20 transistor, and supplied
by an 18V source. The only "audio" from the speaker is a square wave from the
clock chip.

I haven't looked up the max collector current for the MPSA20, but you need to
consult the datasheet for that, and calc the impedance for the speaker from
that. I'd suggest something like a 100-ohm speaker for this clock.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Life is like a roll of toilet paper; the closer it gets to the end, the faster
it goes.