[TenTec] cw settings

[Ken Brown]

Where do you measure the rise time? When I was in the oldsillyscope 
calibration business, we measured rise time of the leading edge of a 
square wave as the time between 10% amplitude and 90% amplitude of the 
waveform. That makes for a lot less intrepretation of where the rise 
begins and where it ends, which you would have to do if you measured 0% 
to 100%.

I'm not sure about the latest Tek scopes, but the ones I calibrated have 
dashed lines to indicate those points. with the square wave set to cover 
six vertical graticule divisions, we measured the rise time from the 
lower dashed line (1/2 division up from -3) to the upper dashed line 
(1/2 division below +3). This came right out of the Tektronix 
calibration procedure manual in the section for checking whether the 
scope's vertical rise time met spec. (Yes I know that 0.5 does not 
exactly equal 10% of 6, but it is close enough)

DE N6KB