Re: Need a little assistance on Death Race Monitor

From: Matt Rossiter <rossiter_at_ni.net>
Date: Wed Jul 11 2001 - 03:08:54 EDT

Are you sure it's not the same company? The logo on the schematics is exactly the same.

Compare these...

ftp://ftp.rossiters.com/pub/ball.jpg
http://www.ball.com.

They must have some affliliation wouldn't you think? Hmm...

Matt

Rodger Boots wrote:

> Ball Brothers! They made a damn fine monitor back in those days, used in a lot of
> computer terminals. (And, no, they are no relation to the canning supplies people,
> different Ball all together.)
>
> Matt Rossiter wrote:
>
> > A programmable transistor? I've never heard of that before. The choke coil that
> > looks like a resistor is new to me too. This monitor has had all kinds of
> > surprises. Ball Brothers, apparently, is the same company that makes Jars and
> > lids. I had no idea my mom's homemade Jam would have some relation to my death
> > race.
> >
> > Anyway - I've been getting some suggestions from other people privately as well -
> > and Q112 seems to be a likely suspect. When I get home I'll get the scope out and
> > tell you if I'm getting some pulses.
> >
> > Thanks!
> >
> > Matt
> >
> > Rodger Boots wrote:
> >
> > > Wow, a PUT (Programmable Unijuction Transistor) oscillator! THAT's something
> > > you don't see much.
> > >
> > > The "base" (actually the gate) of the PUT (Q112) should be narrow sync pulses
> > > (is any sync is being sent to the monitor) and across the coil (L101) will be a
> > > 60 Hz pulse or ringing waveform. Neither will probably read anything on a
> > > meter, you'll need a scope.
> > >
> > > If you think the PUT may be bad, it crosses to an NTE6402.
> > >
> > > Matt Rossiter wrote:
> > >
> > > > I'm a little stuck on a problem here. I'm not getting any vertical
> > > > deflection. All I get is a thin horizontal line - within that
> > > > horizontal line, I can see things moving back and forth. I was
> > > > wondering if someone could look at the schematics here
> > > > ftp://ftp.rossiters.com/pub/ball-brothers-TG20-23.jpg.
> > > >
> > > > The large vertical deflection transistor is fine. If you look on the
> > > > schematics at the section labelled "vertical oscillator" - at the base
> > > > of Q112 I'm getting zero volts - plus I'm getting zero volts where the
> > > > the choke is below it. Shouldn't I be getting some kind of reading
> > > > around that choke? Just looking for some ideas - I'm not exactly sure
> > > > what the purpose of that choke coil is.
> > > >
> > > > Thanks...
> > > >
> > > > Matt
> > > >
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Received on Wed Jul 11 09:33:42 2001

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