Grounded the CT as it was before at the swinging
choke. The voltage at both ends of the secondary to
the CT is a little of 1700vac.
This is an old Heathkit HA-10 Warrior. The orginial
problem was that the plate volage is low, about
900vdc, and the power out dropped.
Resistance of the two secondary windings to the CT is
58 ohms and 68 ohms(leads lifted).
So far I have checked the oil filled capacitor with a
VOM, the needle swings up at first then drops back
down and shows no continuity to the chassis. Swinging
choke and the plate transformer so no continuity to
the chassis.
Tried another set of 811As with same result. Tried a
spare set of the plug in diodes that repalced the 866A
tubes with same result.
The schematic is here:
http://www.geocities.com/ko4nrbs/HA10ampschematic.GIF
73,
Bill
--- "S. J. Blackwell" <w5lu@hotmail.com> wrote:
>
> No. As one goes out from the core the capacity to
> the core goes down. He
> should ground the CT and recheck. He was measuring
> between the floating
> secondary and the chassis.
> 73,
> Sam, W5LU
>
> >From: "Will Matney" <craxd@engineer.com>
> >To: amps@contesting.com
> >Subject: Re: [Amps] Transformer core shorted to
> secondary winding??
> >Date: Sat, 23 Jul 2005 21:06:26 -0500
> >
> >Sam,
> >
> >If it were capacitance causing this, the voltage on
> either side of the
> >secondary would give an equal voltage reading
> wouldn't it?
> >
> >Best,
> >
> >Will
> >
> >
> >----- Original Message -----
> >From: "S. J. Blackwell" <w5lu@hotmail.com>
> >To: craxd@engineer.com, amps@contesting.com
> >Subject: Re: [Amps] Transformer core shorted to
> secondary winding??
> >Date: Sat, 23 Jul 2005 20:32:37 -0500
> >
> > >
> > > Bill,
> > > Before going off on this transformer, look at my
> off list message.
> > > You are most likely measuring capacitively
> coupled volts with a
> > > high impedence volt meter. Ground the CT and
> remeasure you should
> > > get 1700 volts (or more with late yrs higher
> line volts) between
> > > each side and ground.
> > > Sam, W5Lu
> > >
> > > > From: "Will Matney" <craxd@engineer.com>
> > > > To: amps@contesting.com
> > > > Subject: Re: [Amps] Transformer core shorted
> to secondary winding??
> > > > Date: Sat, 23 Jul 2005 20:14:05 -0500
> > > >
> > > > Bill,
> > > >
> > > > It definately has a high-ohm short in the
> secondary. They've
> > > > wound the primary on the outside which I dont
> like to do. That
> > > > way the secondaries leaking to the core
> instead of the primary.
> > > > If the primary had been the first coil and it
> did that, it would
> > > > blow a fuse most likely. The best check to
> find it is use a
> > > > megger or a hipot, and it would make it show
> quickly.
> > > >
> > > > Best,
> > > >
> > > > Will
> > > >
> > > >
>
>
> _______________________________________________
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> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
Bill Smith KO4NR
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