[R-390] Speaker

[Michael Murphy]

Good idea Chuck,

Why not a 600 Ohm speaker?

For extra credit, carefully detach the speaker cone and spider from the 8
Ohm speaker voice coil. Unwind the voice coil. Now attach the voice coil
form to a lathe which has been outfitted with a slip mechanism. Wind
approximately 1000 feet of #38 wire in a back and forth pattern. Make sure
that the winding occupies the same footprint as the original 8 Ohm winding.
You should measure around 500 Ohms of DC resistance. The AC impedance will
be higher of course. Glue the voice coil back onto the cone and spider and
reattach the leads. This technique may take practice.

Mike M. WB2UID

http://www.vintage-radio.com/repair-restore-information/valve_philips-speake
rs.shtml

http://www.mwaspeakerparts.com/speaker_parts.html


----- Original Message -----
From: "James A. (Andy) Moorer" <jamminpower at earthlink.net>
To: "Charles B" <ka4prf at us-it.net>; <r-390 at mailman.qth.net>
Sent: Wednesday, September 22, 2004 7:52 PM
Subject: Re: [R-390] Speaker


> Well, you can't really. The don't make them that I know of.
>
> I will be happy to sell you (or anybody else) a NOS military transformer
> that converts 600 ohms to 8 ohms for $15, postage included (US only).
(sorry
> for the appearance of crass commercialism, but I don't really make any
money
> off this - I just do it as a service). Actually, the transformer is marked
> as 9 ohms, but that is close enough.
>
> James A. (Andy) Moorer
> www.jamminpower.com
>
> ----- Original Message -----
>
> > Hi all,
> >
> > where can I find a 600 ohm speaker?
> >
> > Chuck
> >
>
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe: http://mailman.qth.net/mailman/options/r-390