08-11-2017, 08:41 AM
For all the superb capabilities of PC based devices and digital scopes I'm still a fan of analogue. Not just because it's more familiar but an ingrained understanding of how and when it tells lies. All scopes tell lies, it's a matter of knowing what's important and what's not.
In analogue the trace brightness properly portrays how frequent a waveform is, very useful in television which is my main area. For example field sync pulses show dimly in the background of 10us/cm display of lines. I know that DSOs have made great strides in using the Z axis but it's still not like analogue. Though I admit I've not used a high end Tek DPO or similar.
DSOs have a lot of uses. In television it can sometimes be necessary to view a few 10s of nanoseconds of an 8 field PAL sequence which is 160ms. This is a very tough ask for an analogue scope except the MCP Teks which I don't own. I've done it, in a darkened room with a cloth over my head and the scope. Dead easy on even the simplest DSO.
For those who are curious as to why this might be needed, it's to establish the subcarrier to horizontal phase relationship from first principles. http://pangolin.com/TE/354/LAB1401.pdf While this is now very much a legacy issue - nobody is editing in PAL or NTSC - braodcast grade kit still has to get it right.
In analogue the trace brightness properly portrays how frequent a waveform is, very useful in television which is my main area. For example field sync pulses show dimly in the background of 10us/cm display of lines. I know that DSOs have made great strides in using the Z axis but it's still not like analogue. Though I admit I've not used a high end Tek DPO or similar.
DSOs have a lot of uses. In television it can sometimes be necessary to view a few 10s of nanoseconds of an 8 field PAL sequence which is 160ms. This is a very tough ask for an analogue scope except the MCP Teks which I don't own. I've done it, in a darkened room with a cloth over my head and the scope. Dead easy on even the simplest DSO.
For those who are curious as to why this might be needed, it's to establish the subcarrier to horizontal phase relationship from first principles. http://pangolin.com/TE/354/LAB1401.pdf While this is now very much a legacy issue - nobody is editing in PAL or NTSC - braodcast grade kit still has to get it right.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
