From vanclee–(at)–ga.com Sat Sep 2 17:22:50 CDT 1995
Article: 800 of rec.audio.tubes
Path: geraldo.cc.utexas.edu!cs.utexas.edu!swrinde!gatech!news.sprintlink.net!bga.com!bga.com!nobody
From: vanclee–(at)–ga.com (Henry van Cleef)
Newsgroups: rec.audio.tubes,alt.guitar.amps
Subject: Re: Running Champ with 8 ohms instead of 4 ohms
Date: 2 Sep 1995 01:01:09 -0500
Organization: Real/Time Communications – Bob Gustwick and Associates
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References: <422p1s$g3--(at)--anix2.panix.com> <426she$7u--(at)--nrp1.primenet.com>
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Xref: geraldo.cc.utexas.edu rec.audio.tubes:800 alt.guitar.amps:3304

In article , mgsam wrote:
>
>On another subject, I have a couple of champs in for repair right now and
>I got ahold of a Fender replacement part power transformer. The wiring
>doesn’t match up with the original and they sent no technical bulletin.
>GRRRRRR. Anybody have any ideas?
>
Get out your trusty Simpson meter and ohm the thing out. The high
voltage winding will the the highest resistance and will have a center
tap. The primary will have the second highest resistance and no center
tap. If it is a 115/230 volt setup, there will be two windings
virtually identical ohms.

The heater windings (and rectifier filament) will look like almost dead
shorts.

Once you have the primary identified and the other windings figured
out, put 110 volts on the primary and measure the other voltages. If
it is a two-primary transformer, connect one end of the second primary
to one of the terminals on the first, and measure the voltage across
the other two terminals. Zero volts, you’ve got them phased correctly,
just parallel them for 110 volt operation. If you see around 230
volts, you have them backward from each other. Reverse the wires on
the second primary and run them in parallel. For 220 volt operation,
connect the two primaries in series rather than parallel, after phasing
them as above.


***********************************************************
Hank van Cleef vanclee–(at)–ga.com vanclee–(at)–mn.com
***********************************************************

 

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