Do I need a scope?

[clockman]

I have a large collection of vintage radios i have repaired to a basic standard i have all the basic test equipment? but am thinking of buying a second hand scope my question is do i need one for basic radios and which make and how much should i pay. TAB

You don't need one, they are good tools to have though. A basic 20MHz CRT one is probably the best to start with, say £30 to £150. Forget cheap digital ones unless you know and can compensate for their shortcomings. Expensive digital (a few hundred pounds upwards) OK.

[frankmcvey]

Certainly very nice to have, and the more you use it, the more use you'll find for it. Using the essential/important/desirable scale, I'd say that it's not essential, but I'd rate it as important. You should be able to pick up a decent wee scope for around £80 or so.

Cheers,

Frank

[Boulevardier]

Originally Posted by merlinmaxwell

You don't need one, they are good tools to have though. A basic 20MHz CRT one is probably the best to start with, say £30 to £150. Forget cheap digital ones unless you know and can compensate for their shortcomings. Expensive digital (a few hundred pounds upwards) OK.

I agree! Good two-channel 20Mc/s analogue scopes can be had second-hand for not much more than the cost of a good digital multimeter.

As a new user, avoid digital scopes - their controls are non-intuitive, and there’s a steep learning curve to make sense of the endless complex menu systems by continual reference to badly-written user manuals. Analogue scopes tend to have all functions immediately and obviously accessible on the front panel, rather than buried deep in obscure menus.

Mike.

[OldTechFan96]

I bought a Hameg 203-4 in 2018 for about £50, including postage. It came from a massive collector of oscilloscopes.

Try and keep any money spent to a minimum because oscilloscopes sold online usually have no history, are untested and don't include any accessories such as probes.

Hameg 'scopes are a good bet because service info is easy to obtain and they don't use exotic, propriety components.

You could posted a 'wanted' ad on the forum.

[SiriusHardware]

I would agree that if you have never used a scope before and your work is going to be entirely on analogue equipment (not computers or digital circuits) then a 'classic' analogue scope is the better route to take.

I would hesitate to suggest buying any analogue scope which is not collect-only - I just don't think they travel well especially in this day and age where carriers don't seem to exercise any care at all in the handling of items. I'm not even sure that I would put an old scope in the post in its original box with the original polystyrene packing nowadays.

Hameg scopes, mentioned earlier, all include a useful V/I component tracer as standard - it takes a bit of acquired knowledge to use one but once you are used to them they are very useful for testing transistors, diodes, capacitors etc, often without even taking them out of circuit.

[Radio Wrangler]

Scopes don't directly measure current or resistance, so there's still plenty of uses left for a multimeter, but a scope shows you pictures, you see more of what's going on and you can see things which make you suspicious of subtle faults. You can learn more and faster with a scope.

Some people will tell you that you don't need a scope, but you'll find they have a lot of experience, and that experience allows them to interpret things a multimeter shows them in difficult cases. The scope gives you more clues and makes life easier.

Scopes used to be expensive and big workshops could afford one. It came out for special jobs. I worked in R&D in a test equipment firm. We could have anything and almost everything that we wanted. Here, engineers reached for scopes and spectrum analysers first. Multimeters and bench voltmeters were only used when some voltage needed to be particularly accurate, or a resistance check was needed. These people had lots of experience and cost was no problem.... they went for scopes first.

David

[chriswood1900]

I would say go for it, I find scopes great fun to play with and learning to use it will enhance your hobby. Once you are familiar with it you will find repairs easier. As others have said 20MHz should be OK but if it goes higher so much the better but I would suggest sticking with an analogue unit for starters . If you are in no hurry the BVWS events and sales can be a good source there is an Auction coming up shortly on line.
If you want to understand more I recommend the following sites.
The Tektronix XYZ https://xdevs.com/doc/Tektronix/XYZ_...ITAL_SCOPE.PDF
and a lecture by one of their sales team on YouTube to a Ham group https://www.youtube.com/watch?v=067W7h1BhxE
An understanding of Probes which you will need to get the best from a scope https://w140.com/tekwiki/images/d/d6/60W-6053.pdf

[G4YVM David]

I have a scope which is rarley used now. I am having to clear out a load of stuff so if youre interested send me a PM.

I recently sold two for a friend for £100 each but mine will not cost that, nothing like as much.

If you arent interested...no worries!

[paulsherwin]

You will find a range of opinions about this, and it's really down to personal preference. People with a background in professional electronics will have used scopes all their working lives and tend to view them as essential, while amateurs like me tend to think they're more trouble than they're worth given their bulk and weight. They do make some jobs a lot easier though, such as looking for noise on voltage rails.

You can pick up professional lab grade scopes from the 70s for very little money (and sometimes for free) if you have a suitable dedicated workshop in which to use them. They aren't suitable for plonking on the dining room table though.

It's best to avoid valve scopes unless you are interested in restoring one.

[David Simpson]

Go for a decent Hameg Scope. 20MHz Bandwidth, 2 Channels, and - a Component Tester. Ideal for all vintage domestic radios, amps, and Sig Gens. But not for AM or FM VHF radio stuff (except for their audio circuitry). Waveteks & Goulds would come 2nd best. Obviously, HP & Tektronix lead the pack, but are expensive to acquire & repair. If you actually want a vintage scope to use on vintage radios - I have a soft spot for the Solartron CT436.

Regards, David

[Radio Wrangler]

Don't be put off by all the knobs and complexities of high performance lab scopes. All you have to do is to learn which knob positions park the features you don't need. You can then drive them like a basic model. Having them on a crib card is not cheating! If a serious scope turns up at an attractive price when you're looking, then go for it. Don't be put off. Plenty of people here will guide you round it.

If, at a later date, you learn a bit more and could use something a bit deeper, then those features you've been avoiding are sitting there ready for you to need them.

There is a lot of attraction for simple, non-intimidating scopes from people getting started. But if you learn what to park on the scary scopes, you'll look a right wizard... just so long as you don't let anyone see you using a crib card

Whatever you get, learn how to drive it as a single channel single timebase instrument. Most of your effort will go into learning about a triggered timebase. You really really want a triggered timebase. Older scopes (nearly all valved in that era) were rather bodgy in terms of synchronising the timebase to get a stable picture. Later you extend your horizon into using dual channels to compare signals in two places in the radio/amplifier you're fixing.

Choose to learn your way around the scope as you need things, and each new feature ceases to be a chore and is a white knight helping you when you need it.

You don't have to understand it all at once.

David

[Tim]

If you’re going to be doing valve stuff, make sure any scope you get has a decent maximum “ volts per division” on the y amps. 10 volts per div at the minimum, 20 volts better. Don’t assume( as I did once) that all scopes are the same in this respect, or you could end up with a nice enough scope with a 2volt per division maximum and have to buy a x100 probe( or two) in order to make any meaningful measurements in valve circuits.

[duncanlowe]

I'm going to be controversial here. Maybe because I have used many kinds of 'scopes over the years.
I started with plain old single channel triggered timebase analogue scopes. Proceeded on to analogue storage scopes and even an early DSO called an Analogic. And then all sorts of DSOs and other stuff.
Why I'm going to be controversial is suggesting that PC based stuff isn't scary or difficult to use. I can kind of see why anyone who only knows analogue scopes might not find their way around them, and also understand that there are some where the UI is a bit, well, rubbish. But my favourites are Picoscopes.
IF, you are very familar with analogue scopes, then I could see they aren't immediately something you could transfer to. But here we are talking about someone who doesn't have prior knowledge of analogue. I have a medium level version of one of their devices. 4 channel input plus and arbitrary waveform generator output. Separate external trigger input too.
For me, another benefit is that it uses the PC that is already on my bench so the box is pretty small compared to even a small display scope. But then, the display is the size of my PC monitor!
OK, there are limitations and the one I have isn't the cheapest version. But if you are a beginner, and don't have the history, I'd start the learning with a PC based device.

One thing, though. If you do go PC based, don't buy rubbish. It will be really hard to understand and will stress you out.

There are, also, other digital options. It's possible to get very basic, but surprisingly useable things with a built in small LCD, HOWEVER they have really hard to figure out UIs unless you are familiar, so avoid for now even though they are relatively peanuts.

[Pamphonica]

Just a small suggestion. Don't forget to get decent probes for the scope. You don't need much bandwidth (20-50MHz is more than enough for a basic scope).
But DO look for a proper voltage rating. You will be connecting your nice scope to circuits with 200-300V on. You don't want to fry the input.
My tip is to look out for used Tektronix (or RS, or Coline) probes rather than buy cheap new Chinese. These have a voltage rating that is real. Especially those rarely loved chunky old Tek probes (like the Tek 6006). These have a 600V rating and keep your fingers well protected from the HT!
-Jeremy

[duncanlowe]

Originally Posted by Pamphonica

Just a small suggestion. Don't forget to get decent probes for the scope. You don't need much bandwidth (20-50MHz is more than enough for a basic scope).
But DO look for a proper voltage rating. You will be connecting your nice scope to circuits with 200-300V on. You don't want to fry the input.
My tip is to look out for used Tektronix (or RS, or Coline) probes rather than buy cheap new Chinese. These have a voltage rating that is real. Especially those rarely loved chunky old Tek probes (like the Tek 6006). These have a 600V rating and keep your fingers well protected from the HT!
-Jeremy

Yes got to agree about decent probes. Have Colines myself, though I do trust the ones that came with the picoscope.

[David Simpson]

Hello clockman,
When it comes to learning practical hands-on usage of tools & test equipment, of late, I've been advising Forum folk to seek personal mentoring (covid restrictions permitting) from friendly experienced VR folk in their locality. There must be dozens of Forum/BVWS/VMARS/ARS/etc. enthusiasts within a stone's throw of Borehamwood. And, no doubt, many of them have been using scopes for years.

Regards, David

[Sinewave]

Also if you are probing near mains potential, be aware that when the scope input says 250v, that's often peak and not RMS.

[Radio Wrangler]

With a reasonable scope, you'll need a x10 ratio probe. You'll only rarely need a x1 one.
When looking for probes, buy simple x10 ones. The switched dual range x1 / x10 ones have disadvantages AND it's far too easy to knock the switch. So keep a x1 probe separate. I paint x1 ones a bright colour!

There are all sorts of things you can add, current sensing probes, RF detectors.

David

[AdrianH]

A word of caution here that I have not seen mentioned. Mains powered scopes are typically grounded, i.e earthed.
Yes you can, and many do remove the earth wire from the ground pin in the mains plug. Many of the old valve radios will be universal chassis or auto-transformer input, even if you have neutral to chassis on the radio, connecting the scope probe ground to it can trip your house breakers. If you are considering using the scope for your radio repairs then run them through an isolation transformer so that chassis can be earthed.

There are ways and means around everything, but be cautious, tripping out the house electrics may not hurt you directly, but stopping the recording of a favourite TV program or the Oven going off during prep for a meal can hurt you more.

Adrian