[Boatanchors] voltage on the speaker???

[Glen Zook]

The AR-3 is too new a design (they came out in late
1955) to use the old field coil type of speaker.  They
use a PM type speaker.

It sounds like John either has a bad audio output
transformer or else a wiring error.  The only
connections to the voice coil should be to the "high"
side of the secondary coil on the output transformer
and ground.  The "low" side of the transformer goes to
ground.

Actually, it sounds more like bad wiring because if
the audio output transformer is wired correctly if the
B+ were connected to the output side of the
transformer then it would be basically shorted out
because the very low resistance of the output is
around 3 ohms which would wipe out the B+.  I think
that the speaker is wired to the primary and not the
secondary!

However, it is possible that the transformer is
shorted and that the ground side of the secondary has
been removed.  Then, again, this is a wiring error!

Glen, K9STH


--- jeremy-ca <km1h at jeremy.mv.com> wrote:

Does that use a PM speaker or the older dynamic type
that runs B+ thru the electromagnetic coil on the back
of the speaker? There should be no voltage on the
voice coil that is attached to the cone in either
type.

Best bet is to unsolder some leads and Ohm it out.

Glen, K9STH

Website:  http://k9sth.com


       
____________________________________________________________________________________
Building a website is a piece of cake. Yahoo! Small Business gives you all the tools to get online.
http://smallbusiness.yahoo.com/webhosting