Correcting Oscillscope Trace

[evingar]

Originally Posted by MrBungle

I had a DS1054Z for about 2 months. I sold it to a coworker in the end (who sold it on as well) because TBH I didn't need the features and I wasn't totally happy with the software. As a software person by day I am somewhat sensitised to UI and software issues and it irritated me. The really good thing is the FFT function which works as a somewhat shonky spectrum analyser, and the slow sampling rates, but I've got to be honest, the rest of the experience is somewhat bumpy and menu driven which is horrible and the digital side of it, you might as well buy a £20 logic analyser from ebay and use that. Much as the £1k I plopped on a Tek DSO, it sat there while I used my £10 Philips analogue scope.

I understand where you're coming from. I have a DS1054Z and a Tek 2465B on my (others are on the equipment rack). I usually reach for the Tek first. However, it really is horses for courses and for some things you really need a digital scope. It's also invaluable for documenting waveforms.

I (seriously) don't think you can better a DS1054Z for value-for-money, it really does punch way above its weight and I'd recommend it for someone looking for a new scope at the budget end of the market.

[WME_bill]

Correcting oscilloscope trace.
It would help to identify the model if you post a photograph. It sounds like a Crotech.
Philip Harris were school suppliers who re-badged equipment, as also did Griffin and George. Crotech were sold under Harris and Gould names. It is probalby not a Scopex model, as they were rebadged and sold by Avo and also I think Racal.

Your tube number is not complete. It should be D14-xxx/GY.123. I expect it will be D14-363, by Philips/Mullard/Herleen. 1985 to 2006.
Do not scrap the tube quite yet. Your fault is what was called trapezium distortion years ago. It could be caused by incorrect voltages on the tube and the deflection plates.
If you cannot locate a manual, I have data sheets on various CRTs which will give you the likely tube operating voltages once we have identified the type.

Have you checked the voltages around the whole circuit?
You do not say, but does the distortion come only on Channel1?
If you align the trace horizontal at the top of the screen, what happens when you move it to the bottom?

I endorse what mikehennessy says. An analogue scope is much easier to "drive" and to learn upon. And to service and keep working.
I use an analogue scope most of the time when fault finding on radio and test gear as it is quicker to change ranges.
And for alignment with a wobbulator, I find an analogue storage much preferable, as it is easy to set to avoid flicker while giving a fast response. I use a Telequipment DM63, which I know mikehennessy likes. I prefer it to a HP1741 which they have tried to make fool-proof, and this fool finds difficult to use.
wme_bill

[MrBungle]

Another nod towards the Telequipment scopes. I've had a D83, a D61 and an S61 over the years. The D83 was a marvellous scope.

Second to that is Philips analogue units. Well documented, literally made of jellybean parts, well engineered and nice and cheap

Originally Posted by evingar

I understand where you're coming from. I have a DS1054Z and a Tek 2465B on my (others are on the equipment rack). I usually reach for the Tek first. However, it really is horses for courses and for some things you really need a digital scope. It's also invaluable for documenting waveforms.

This is true. I need a digital scope once in a blue moon, mainly for really slow things like monitoring PLLs with a very long time constant, playing around with a spectrum analyser I'm working on which doesn't have a fast sweep and debugging digital logic that has rare triggerable events that are difficult to see on an analogue scope. Fortunately a good compromise, another Philips scope thanks to a forum member for a very reasonable amount of money, turned up as it was broken. Some not too extensive repairs in progress and it's good enough for my digital needs:

I (seriously) don't think you can better a DS1054Z for value-for-money, it really does punch way above its weight and I'd recommend it for someone looking for a new scope at the budget end of the market.

Definitely. If a DSO is your first scope you'll probably be fine with them. DS1054Z certainly is value for money.

[factory]

Originally Posted by WME_bill

Correcting oscilloscope trace.
It would help to identify the model if you post a photograph. It sounds like a Crotech.
Philip Harris were school suppliers who re-badged equipment, as also did Griffin and George. Crotech were sold under Harris and Gould names. It is probalby not a Scopex model, as they were rebadged and sold by Avo and also I think Racal.
wme_bill

Philip Harris are still supplying oscilloscopes and other equipment for schools, including a newer 30Mhz version of the 3305 (25Mhz) oscilloscope being discussed here, as well as a single channel analogue "student oscilloscope".

Here is a picture of the 3305 oscilloscope, not the best picture but I couldn't find much for it on the web and the newer version (can't quite read the model no.) from the Philips Harris website.

David

[Radio Wrangler]

Educational instrument purchasers have different priorities to the market outside education. The equipment made for them is designed to demonstrate things rather than go into the difficult applications. They are intended for beginner's lab sessions for people learning what a scope is and to learn the basics of using one. The people in the university needing to use one in anget will have something heavily discounted from Tek or keysight to get serious with.

David