Re: Horizontal Width Question

  thanks Rodger.... that was good info... I have a good picture now
(sizewise at least). Here is what I did...

After increasing the deflection capacitor from a .39 to a .64 and
hitting threshold as far as how much I could decrease the H-width, I
installed a second adjustable inductor in series with the stock h-width
coil. That allowed me to bring the right side of the screen where it was
supposed to be.

Based upon your comments, I took the retrace cap *down* from .01 to
.0076 just to see what happened.... WHOA, little change big effect. With
this config I had a significantly smaller screen in both horizontal and
vertical size. My Anode voltage jumped up to 22KV so I backed the B+
down until the anode was again at 19.5KV. With this, I now was able to
remove the second width coil, increase my sizes and shift into position
for a perfect fit... my secondary voltages (screen, focus, +24V, +15V
and +125V were withing working tolerance). So here is the summary...

Deflection Capacitor (between deflection coil and ground)

    * Increase Capacitance: Moves right side of screen inwards/left
      (smaller), however taking this past a threshold started causing
      wrapping on the right side too
    * Decrease Capacitance: Move the right side of screen outwards/right
      (larger)

Retrace Capacitor (between HOT Collector and Ground) **** Watch out for
X-Rays, better have a HV probe if you mess with this

    * Increase Capacitance: Moves left side of screen outwards/left,
      decreases secondary voltages on flyback substantially
    * Decrease Capacitance: Moves left side of screen inwards/right,
      increases secondary voltages on flyback substantially

thanks again

jess

On 1/31/2011 7:43 PM, Rodger Boots wrote:
>
> Messing with the retrace capacitor value mostly changes the high
> voltage level. Decreasing B+ should help, increasing width coil
> inductance is the best way.
>
> On Jan 31, 2011 8:32 PM, "Jess Askey" <jess@askey.org
> <mailto:jess@askey.org>> wrote:
> > Im about finished hacking my WG7000 flyback into my Amplifone raster
> > deflection board and my last issue is with the Horizontal Width. Right
> > now it is too wide... from several articles online about this, I
> > attempted to increase the size of the deflection capacitor which is at
> > the end of the chain of...
> >
> > HOT -> Deflection Coil -> Horizontal Width Coil -> Parallel LR Tank ->
> > Deflection Capacitor (.39uf)
> >
> > I took this up to .64 which helped but not quite enough so I took it up
> > to .64 + .39 and it didn't decrease much less than just the .64....
> so I
> > think I hit my limit. So... Im trying to figure out what my next
> options
> > are... I think I can....
> >
> > 1. Put a larger inductance width coil inline
> > 2. Put a resistor in series with the cap
> > 3. Lower the B+ (not a great option)
> > 4. Put a resistor in parallel with the H deflection coil (not a great
> > option either I don't think)
> >
> > Does anyone have any suggestions or 'best practices' beyond the
> > capacitor change? One page mentioned lowering the retrace cap but I
> > didn't think I would want to mess with the retrace (or would that help
> > move the left edge of deflection farther left?) Right now, I need to
> > take my right edge farther left. This monitor also has a horizontal
> > shift which has quite a wide range so I have lots of options.
> >
> > thanks
> > jess
> >
> >
> >
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> chris@westnet.com <mailto:chris@westnet.com>

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Received on Wed Feb 2 22:53:27 2011