This is what a 'scope camera is for. Typically, the camera uses Polaroid film, and has a hood that mounts the camera a fixed distance from the scope screen, while blocking out the room light. You open the shutter and do a single sweep. Close the shutter, develop the film, and voiala! Phillip -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Bob Ammerman Sent: Thursday, April 18, 2002 9:18 PM To: PICLIST@MITVMA.MIT.EDU Subject: Re: viewing non-periodic waveforms with an analog scope Point a video camera at the screen, tape it and freeze frame the result? This will only work if the waveform occurs while the CCD is capturing the image. Bob Ammerman RAm Systems ----- Original Message ----- From: "Donovan Parks" To: Sent: Thursday, April 18, 2002 9:21 PM Subject: [EE]: viewing non-periodic waveforms with an analog scope Hello, I have a Tektronix 465 analog scope and it works wonderfully for viewing periodic signals. I've now come to the point where I need to view a 40kHz square wave that lasts for only three periods (and thus is non-periodic). I can set the scope to single sweep mode and get it to trigget on the first rising edge, but the signal disappears far to fast for me to analysis it. Turning the time base down doesn't help as the width of the signal shrinks in proportion. Is there any way to use an analog scope to view this waveform? Would a digital scope solve my problem (I could at least try and capture the screen with a digital scope)? What do others do when trying to observe non-periodic waveforms? Thanks, Donovan -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.