[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [TCML] Scope Issues
It's an older "Leader" brand 2-channel, 15MHz scope, probably second generation of the solid-state age, judging by its appearance. Its new enough to have a few ICs mixed in with the discrete devices. It does have a triggered sweep and the normal bells & whistles one would expect on a modern analog scope. It auto-triggers just fine and gives a stable display with weak RF signals, as I have tested it using a reasonably well calibrated function generator. I might just dump the dipole and dangle a regular probe near the TC.
Thanks,
Greg
--- On Thu, 5/7/09, Lau, Gary <Gary.Lau@xxxxxx> wrote:
> From: Lau, Gary <Gary.Lau@xxxxxx>
> Subject: RE: [TCML] Scope Issues
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Date: Thursday, May 7, 2009, 9:09 AM
> While the timing between successive bangs is extremely
> erratic when using a static gap, if one adjusts the sweep
> speed to show just one bang to the point of quench, the
> bang-to-bang repeatability is actually quite good and will
> show a reasonably stable display. There will be some
> variability in bang amplitude from bang to bang, and this
> will result in differences in quenching, but one can usually
> overcome this by setting the trigger threshold high enough
> to just trigger on the highest bangs. So the scope must be
> set to the trigger mode that shows no trace at all when the
> coil is off or when the trigger threshold is set too high.
>
> If one is using a very old or cheap scope that does not
> have triggered sweep, then this probably won't work, but
> I've never tried using such a scope. What kind of scope
> are you using?
>
> Regards, Gary Lau
> MA, USA
>
>
>
> > -----Original Message-----
> > From: tesla-bounces@xxxxxxxxxx
> [mailto:tesla-bounces@xxxxxxxxxx] On
> > Behalf Of Phil Tuck
> > Sent: Thursday, May 07, 2009 9:39 AM
> > To: 'Tesla Coil Mailing List'
> > Subject: RE: [TCML] Scope Issues
> >
> > Greg.
> > I can't answer your problem directly, but I have
> tried a similar thing and
> > had some minor success, but if you like me have a
> static gap which at 1KW
> > I'm guessing you may have, then you might be
> disappointed at what you get
> > anyway, as the SG is a bit too eratic to get a decent
> sync on for the scope.
> > If that turns out to be the case, try photographing
> the 'scopes display like
> > I did, and you may be lucky enough to capoture a
> 'frozen' trace of what you
> > want.
> >
> > Regards
> >
> > Phil
> > www.follytowers.co.uk/tesla
> >
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: G Hunter [mailto:dogbrain_39560@xxxxxxxxx]
> > Sent: 07 May 2009 01:58
> > To: tesla@xxxxxxxxxx
> > Subject: [TCML] Scope Issues
> >
> >
> > I tried to observe my SGTC quench on my o'scope
> tonight. No dice. This is
> > the first time I've tried it. I set up a simple
> horizontal dipole about
> > 15ft from the 1KW, NST-based coil. I used two
> 18" wire elements across a
> > 47ohm resistor. I set up the scope for a good-looking
> 200kHz sine wave from
> > my sig gen, then plugged in the dipole to CH1 and went
> for it. The scope
> > displayed zip, even at 5mV/div. I tried vertical
> polarization too. No
> > help. I removed the resistor. The scope now became
> sensitive to 60Hz noise
> > and showed me a fuzzy trace. Good! Still no help.
> The snarling TC across
> > the room inspired not even a quiver from the mocking
> trace. I'm stumped.
> > The vacuum cleaner motor on my sucker gap causes
> plenty of 60Hz hash on the
> > scope, put the screaming coil causes no change in the
> display. Were I a
> > gambler, I would've bet the TC RF signal would be
> detectable from 10s of
> > yards away. What am I doing wrong? Should I simply
> move the antenna
> > closer to the coil? I don't have enough coax to
> do that at the moment, but
> > I can get some.
> >
> > Cheers,
> >
> > Greg
> >
> >
> >
> >
> >
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla