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 13:39:07 2001
This archive was generated by hypermail 2.1.8 : Tue Dec 02 2003 - 17:51:26 EST
