[NJARC] In search of an 8 inch zenith electromagnet speaker, 2150 ohms.

[John Ruccolo]

Tom,

Perhaps that's just a production variant. Do you have
any evidence that the speaker was not original to the
set? Plus the sechmatic could be wrong. And even it
it's not, manufacturers frequently made mid-production
changes. 

Also, don't worry too much about feed coil speakers.
Exact replacements can be difficult to find. And from
what I remember, you *don't* need the speaker, just
the output transformer (for which a replacement from
AES or Radio Daze is easy to get and fairly cheap).
Also, a transformer from a parts set should work. What
did that set use, a single 6F6 for output?

My advice for replacing an electrodynamic speaker is
to replace it with a permanent magnet speaker and use
a filter choke (or sometimes a resistor) in place of
the field coil. You're fortunate that the speaker is
still good, I think.

JR


--- Thomas Lee <thomas_v_lee at hotmail.com> wrote:

> Visit our web site - See http://www.njarc.org
> _______________________________________________
> Hi John,
> the speaker that the radio has is not what the
> schematic calls for, it's a 
> model 49-166X 1000 ohm, the schmatic calls for a
> model 49-152, 2150 ohms. 
> Should I keep the speaker and add a resistor in
> series once I find a 
> transformer?
> 
> Thoughts?
> 
> 
> Tom
> 
> btw go to sleep :)
> 
> 
> 
> Tom,
> If this is the radio we were working on at the
> clinic, you DON'T NEED the 
> speaker -- you need to replace the OUTPUT
> TRANSFORMER which is physically 
> mounted on the speaker. The speaker field coil is OK
> (we tested that at the 
> clinic), and I think we tested the voice coil and
> it's OK too. But check it 
> to make sure.
> 
> It should be easier just to replace the transformer
> -- it will be much 
> harder to locate a matching speaker. The primary of
> the output trasnformer 
> tested *open* (or you've got a broken wire
> someplace, but I doubt it).
> 
> JR
> 
> 
> --- Thomas Lee <thomas_v_lee at hotmail.com> wrote:
> 
>  > Visit our web site - See http://www.njarc.org
>  > _______________________________________________
>  > if you have one send a pic, and a price :)
>  >
>  > thx
> 
> 
> _______________________________________________
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> http://mailman.qth.net/mailman/listinfo/njarc
> 



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