Re: Need a little assistance on Death Race Monitor

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 Tue Jul 10 13:59:08 2001