[NJARC] Oscilloscopy Questions...

[Scott Roberts]

Hi All- (I am reposting this to the reflector with additional information...)

My original question to John, who suggested posting it here: 
"I have been looking at e-bay for ossci probes(I have none for the nice LabVolt 798 on which I can find no info) and I am confused- should I just buy by price or what? I need 4- one for the output & 1 for each of the three inputs. I find something like 500 on the buy it now for 100mhz Oscilloscope  Probes... I really don't want to buy direct from Hong Kong or China if I can buy from a dealer in the US. I know to look for a 1x/10x What else should I be looking for? Should one be high volt (<2k volts)? Or not a worry?"

The oscilloscope has 4 main BNC connections on the front- 
Ch. 1 or X in
Ch. 2 or Y in
Ch. 3 or Ext Trig In
CH. 1 Output 25 Mv/DIV into 50 ohm Term
and one on back:
Z AXIS INPUT Blanked by TTL H Level

Figure I need a connect up for each one...

I futzed with it a bit last night, and found it has some neat stuff, which I am sure will really be useful once I have probes and some idea what I am doing... When on, it gives two traces to start- and they can be run independently, or both at the same time. You can also get them to "Add" which forms a third trace. Then, you can pop out a knob, and get a third channel trace, and pull another, and you get "QUAD", another trace setup! As mentioned previously, there is a "CH.1 OUT" BNC on the face as well. I have a rough idea how to make it do things, but no real understanding of what I am doing with it yet. I have figured which controls do the basic operations- move the trace up, down, left, right, etc; intensity, focus.

More detailed info: 
The "V-Mode" panel includes: CH-1, ADD, CH-2, CHOP(which puts all the traces up) and ALT, and X-Y

To the left of the CH1 & CH2 Volts/Div knobs are an "AC-GND-DC" selector for each.

There is a CH-2 INV switch.

A Calibration connection.

Horizontal Display panel offers A, and a selector switch forb labelled Trigger & TV-H(A at TV-V) on the one side of the switch, AFTER DLY on the other, with the parameters "INTEN BY B, ALT, B" as its choices.

Sweep Mode offers Auto, Norm, and Single.

The A-Trig panel has COUPLING(AC, HF rej, DC, TV-V, TH-H) and SOURCE(ALT, CH-1, CH-2 LINE, .2V/DIV, 2V/DIV [these last two are associated with CH-3, or EXT TRIG IN BNC])

There is a SLOPE control, which basically inverts the sine polarity, as well as the usual VOLTS/DIV for CH-1 & CH-2 (5mV-5V, with a Variable x10 mag switch, .5-2mV) and one main Time Delay(dual switch- A & B) .02 uS to 50 mS, on both, and .1-.5 S on A ONLY. Also a vernier DLY Time Multiplier and an AB TRACE SEP switch, with an A VARIABLE pull out center knob.

I can get a sine wave on it, but not much else- and that is only when in certain positions...

Thanks for any help!


Scott


--- On Wed, 8/25/10, John Ruccolo <jr6v6gt at yahoo.com> wrote:

> From: John Ruccolo <jr6v6gt at yahoo.com>
> Subject: Re: [NJARC] tv/radio repair shop inventory for sale
> To: "Scott Roberts" <ng19delta at yahoo.com>
> Date: Wednesday, August 25, 2010, 12:39 AM
> Scott,
> 
> I would put that question on the reflector, or ask Al Klase
> and/or Steve 
> Goulart, since they're way better than me with scopes.
> 
> Why do you need a probe for the scope.s *output*? What's up
> with that??
> 
> JR
>