On Thu, 23 Nov 2000 16:06:42 -0000 Peter Chadwick
<Peter_Chadwick@mitel.com> writes:
>>
>>Rich said:
>>I use a BNC "T" with stiff wires soldered to the pins on one side.
>>This allows me to clip on a 100 to one oscilloscope probe, allowing me
to
>>measure V across 50-ohms.
>I haven't seen an analogue 'scope guaranteed to an accuracy of better
>than +/-5% of full screen. That means a possible power error of around
+/-10%,
>excluding probe errors.
This is interesting, my Tektronix 2246 has a vertical deflection rating
of WITHIN +- 2% 15deg C thru 35deg C!
And it's SmartCursors (tm) Voltmeter has +- .5% of reading of reading +
2%
of one vertical division + 250 microvolt under DC voltage measurement,
In AC measurement 25hz thru 25mhz it's +- 2% of reading +15% of one
vertical
division + 1 millivolt. Above 25mhz to greater than 100mhz it's +
.5db/-3db
+- 1 milivolt and follows the trigger system's frequency response curve
which
is excellently rated for a scope of it's class.
Now I think these numbers mean you have now seen one scope that does.
>Digital ones can get to 1%, although you have to watch
>analogue bandwidth ratings, and aliasing problems if you're not running
single
>tone. Add the probe error too.
Good poynts |-).
>Any of these methods requires calibration against a known power source
at the >frequency of operation. 73 Peter G3RZP
This isn't an issue with real measurement men! We always test/meausre
standards
before any critical measurements. And all measuring equipment is past
their
warmup period.
73, Jerry krr2ak@juno.com
[text|uuencode|59kb ea]
'Y2K ? Because 1k is 3 decibels down in amplitude. 9991 krr2ak'
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