I was interested in total rise time, so I measured from 0% to 100%, plus or
minus 0.1 ms as best I could judge by eye, but the very distinct and uniform
waveform made it pretty easy to do at 2.5 ms per division. Quick and dirty,
just to get a rough idea of the relationship between indicated and actual.
Bob NW8L
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Ken Brown
Sent: Friday, November 18, 2005 10:41 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] cw settings
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
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|