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Hi Morris,

You don't really have to have a capacitance standardizer to calibrate your 1A1. The
description of the capacitance standardizer provided by Phil is quite accurate. Let me
review the goals we are trying to achieve by making the 1A1 adjustments using the
capacitance standardizer:

1. You want to make sure the input C of the 1A1 is close to the value stated on the
front panel so that the recommended probes can be properly compensated to the input of
the 1A1.

2. You want the compensations of each range of the Volts/Division switch to be close
to each other so that you will not have to readjust the probe compensation as you
change ranges.

Once adjusted at the factory, there is hardly ever a need to change any of these
adjustments unless the attenuators have been repaired or some unskilled technician has
been in there and fouled up the factory adjustments. Let's assume the adjustments are
fairly close just as they are now in your 1A1. Here is how to check them:

1. Install a good 10X probe on the 1A1 and think of it just as you would a capcitance
standardizer.
2. Compensate the probe so that the waveform looks good on the 1A1 Volts/Division
position where no internal attenuator is used. (I think this is 50 mV/Div. in a 1A1.)
3. With the compensated probe in place, check the other ranges of the Volts/Div switch
for proper waveforms as shown in the 1A1 manual.

The bottom line is that, in general, a good 10X probe can be used in place of a
capacitance standardizer in almost all cases where Tek calls out the use of a
capacitance standardizer.

Stan
w7ni@...

morriso2002 wrote: