11-05-2023, 11:52 AM
(This post was last modified: 11-05-2023, 11:53 AM by ppppenguin.)
Can you even buy a new analogue scope now?
My Tek 2465B is still centre stage on my bench, the latest in a succession of analogue scopes. But with both this and earlier scopes here are a few things where a digital scope would have been so much better.
1: Debugging the Wireless World Teletext decoder back c1976. Strobing out the clock run-in on a fairly modest analogue scope was very (polite term) difficult. Wouldn't have been easy with my 2465B now. DSOs barely existed back then.
2: Checking PAL subcarrier to H phase relationship from first principles. Looking at a few nanoseconds out of 8 field (160ms). I did manage it on a 2465 but it was black out the room and wait for eyes to dark adapt. My first DSO, the almost laughably simple and crude Tek TDS210 made it easy. Dead easy with my Rigol.
3: Anything to do with PAL 8 field sequence or NTSC 4 field sequence.
And an example where I had no alternative. I think it was Mark's suggestion to do it this way. Not having RTFM I didn't even know the Rigol could display the RMS voltage of an arbitrary waveform. When I was modifying Melford monitors to do 405 I needed to correct the CRT heater voltage which is supplied from a winding on the LOPT. Spiky waveform at 15625 or 10125Hz. Beyond my true RMS Fluke DMM's capability. I had thoughts of doing it with optical comparison (I had more than one monitor) or finding a suitable RMS voltmeter somewhere. I had to float the scope (or maybe I floated the monitor) since neither end of the heater was at ground potential but the measurement worked just fine. I still did a quick optical comparison as a sanity check.
My Tek 2465B is still centre stage on my bench, the latest in a succession of analogue scopes. But with both this and earlier scopes here are a few things where a digital scope would have been so much better.
1: Debugging the Wireless World Teletext decoder back c1976. Strobing out the clock run-in on a fairly modest analogue scope was very (polite term) difficult. Wouldn't have been easy with my 2465B now. DSOs barely existed back then.
2: Checking PAL subcarrier to H phase relationship from first principles. Looking at a few nanoseconds out of 8 field (160ms). I did manage it on a 2465 but it was black out the room and wait for eyes to dark adapt. My first DSO, the almost laughably simple and crude Tek TDS210 made it easy. Dead easy with my Rigol.
3: Anything to do with PAL 8 field sequence or NTSC 4 field sequence.
And an example where I had no alternative. I think it was Mark's suggestion to do it this way. Not having RTFM I didn't even know the Rigol could display the RMS voltage of an arbitrary waveform. When I was modifying Melford monitors to do 405 I needed to correct the CRT heater voltage which is supplied from a winding on the LOPT. Spiky waveform at 15625 or 10125Hz. Beyond my true RMS Fluke DMM's capability. I had thoughts of doing it with optical comparison (I had more than one monitor) or finding a suitable RMS voltmeter somewhere. I had to float the scope (or maybe I floated the monitor) since neither end of the heater was at ground potential but the measurement worked just fine. I still did a quick optical comparison as a sanity check.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
