08-11-2017, 03:22 PM
I suppose it was inevitable that a thread about 'scopes would turn into a Tek love-in...
There's no doubt they played a massive role in advancing the state of the art back in the day, and many the older products really are great - some of them were unparalleled. All of which makes the current state of play so very sad. They are but a mere husk of themselves today, having suffered in the hands of the evil Danaher Corporation - although in fairness, by the time those guys acquired them, they'd lost their way already, having not moved into the digital era along with their competitors. Their DSOs - sad to say - are very poor indeed. To be honest, we've had a lot of problems with our 2465s - and were horrified at how quickly the various custom modules contained within became obsolete. Today, assuming all those custom modules are doing OK, 'scopes of this vintage are now running into problems with their battery-backed SRAM modules... When we eventually throw ours away, I'll be content to leave them in the WEEE skip (although in practice, I'm sure I'll rescue them in the hope the parts will be of use to the Tek collectors).
As I've said many times before, I quite like Philips 'scopes. I haven't seen them all, and I know that some are better than others, but certainly, the PM3215 is a wonderful 'scope for beginners. I've yet to see a better control layout, ever. There is a dual-timebase version (PM3217) if you need it. They are cheap to buy and easy to keep alive - usually, switch cleaner is all you need. In terms of actual faults, I once had to change a transistor (a "jellybean" BF450), and you have to check the RIFA mains cap. At least you can get at that one, though. In our Tek 'scopes, the RIFA is inside the mains filter, which can make things rather more dramatic!
In the interests of full disclosure, I have met one "show-stopper" fault with the PM321x series - the PSU transformer (not the 50Hz mains transformer). I was lucky, as we had a NOS spare at work, but not everyone will be so fortunate. Talking of the PSU, I should say that these 'scope run from 24V DC if you wish, so that's handy for getting around ground loop problems and similar.
Moving up the scale a bit, I've an old PM3295 that is 350MHz. The "A" version goes to 400MHz. This does pretty much everything a Tek 2465A does, and does so with a much nicer user interface. The custom Philips ICs and hybrid modules are reliable, and it runs a lot cooler and quieter than the Tek. No problems with obsolete Dallas-style battery-backed RAM because there is a pair of AA cells installed on the real panel! The LCD displays above the rotary encoders show the settings, so you don't have to use the on-screen text readouts, but they are there if you want them. The acceleration voltage is an impressive 21kV, and you hear the EHT rustling up in a way that reminds you of the gold old days of colour CRTs! The trace is much sharper (with 20MHz BW enabled, of course) than anything I've seen before. IIRC, it's only 16kV in a 2465A.
The big problem with Philips test gear in general is the plastics. Luckily not an issue for the PM3215/7 or PM3295 mentioned so far, but when you move forward to the famous PM3055 with the push-button interfaces, these are less likely to be found in good condition. Most problems are cosmetic though. Not everyone likes the pushbutton interface, but I used these scopes extensively in the early '90s and got to really like them. I was happy to find plenty of them here when I joined in the mid '90s. These have extremely good CRTs, using 16kV acceleration voltage. We always said it was a shame that they didn't put that CRT into the older PM3215/7 models, as that would have been the ideal 'scope for people who prefer the more traditional user interface.
I also have a PM3880A Combiscope. This is badged "Fluke" - they'd acquired Philips T&M by this stage - but it's a Philips design. These are great, great 'scopes. The user interface isn't quite as good as the earlier models, but I get on with it just fine. Lovely bright and crisp 16.5kV CRTs. I have one of the lesser models in the range ("only" 100MHz, 2 channels), but 200MHz versions exist. If you get a 4-channel version, be aware that some of them do it in the same, slightly pointless, way that Tek did it with the 2465 and related models, where channels 3 and 4 have a fairly limited range of deflection factors, etc. A 'scope with trig-view (such as the PM3295) has pretty much the same functionality, frankly. So hold out for a version with the fully-featured third and forth channels...
These Combiscopes are proper analogue 'scopes that transform into a DSO at the press of a button. By modern standards, the DSO functionality is a bit basic, but it's something I have used a fair bit, When I bought it, I regarded the digital stuff as a bonus - I needed an analogue 'scope with a reasonable BW and this one came up at the right time. So, I'd equally recommend the analogue-only equivalents. They run cooler, so the temperature-controlled fan would be quieter in normal use (not that my one is terrible by any means). The plastics are a bit better by this point in time too.
My day-to-day 'scope is still my first ever 'scope - the Telequipment DM63. It's only 20MHz, but it occupies less space on the bench than anything else and doesn't have a cooling fan. I know the insides intimately, and they are easy to repair when needed. They have space for 2 vertical plugins, meaning you have have 4 fully-featured input channels - and on the occasions where I need 3 or 4 channels, they do need to be fully-featured. By default, I use one dual plugin plus the V3 differential plugin, which goes down to 50uV/DIV - albeit at a limited BW of course - which is great for investigating low-level problems (bear in mind the massive dynamic range of audio compared to other things like video). It has analogue storage, which is occasionally useful, but in practice I'd be equally happy with the non-storage version (the D63).
I'm not so enthusiastic about other Telequipment 'scopes, however. The visually similar D83 is good for 50MHz, and is usually found with a dual timebase plugin, but it's not as easy to work on, and not as flexible or "special" - there are no shortage of 50MHz dual-timebase 'scopes out there. I've seen many other Telequipment 'scopes that are completely different in construction and style to the DM63, and would pass over them. The DM63 really was the high-point in their output. I own 3 of them! Of course, Tek owned Telequipment at this point in time, and these scopes owe much to the Tek 5000 series (although I'm not actually sure which came to market first, nor who developed the case, etc). The biggest problem with the DM63 is the Tek custom ICs, ironically
Away from those, I have an old HP 1740A as a bit of a background project. Just when I think it's fixed and ready for calibration, another fault crops up. I should give up and walk away, but it sat in the attic for 7 years until I found a parts mule, so it'll have to get done eventually. It's actually quite a nice 'scope, with a pretty nice user interface and good performance. It was the direct competitor to the Tek 465, and a pretty worthy one IMHO. Much, much easier to work on, no fan, no tunnel diodes, crisper display, cheaper to buy because it's not a Tek, etc. I like it.
I bought a Rigol DS1054Z many years back, and have enthusiastically recommended it ever since. But I always point out that such a 'scope does not replace an analogue 'scope - it compliments one. Broadly, the split is as the name suggests; for analogue electronics, an analogue 'scope is usually the best tool, and for digital work, the Rigol does many things that would otherwise be very difficult or indeed impossible with an analogue 'scope. They are so very different in practice that really, DSOs should be called something else. We now have a dozen here at work - and no longer use our Tek DSOs.
There's no doubt they played a massive role in advancing the state of the art back in the day, and many the older products really are great - some of them were unparalleled. All of which makes the current state of play so very sad. They are but a mere husk of themselves today, having suffered in the hands of the evil Danaher Corporation - although in fairness, by the time those guys acquired them, they'd lost their way already, having not moved into the digital era along with their competitors. Their DSOs - sad to say - are very poor indeed. To be honest, we've had a lot of problems with our 2465s - and were horrified at how quickly the various custom modules contained within became obsolete. Today, assuming all those custom modules are doing OK, 'scopes of this vintage are now running into problems with their battery-backed SRAM modules... When we eventually throw ours away, I'll be content to leave them in the WEEE skip (although in practice, I'm sure I'll rescue them in the hope the parts will be of use to the Tek collectors).
As I've said many times before, I quite like Philips 'scopes. I haven't seen them all, and I know that some are better than others, but certainly, the PM3215 is a wonderful 'scope for beginners. I've yet to see a better control layout, ever. There is a dual-timebase version (PM3217) if you need it. They are cheap to buy and easy to keep alive - usually, switch cleaner is all you need. In terms of actual faults, I once had to change a transistor (a "jellybean" BF450), and you have to check the RIFA mains cap. At least you can get at that one, though. In our Tek 'scopes, the RIFA is inside the mains filter, which can make things rather more dramatic!
In the interests of full disclosure, I have met one "show-stopper" fault with the PM321x series - the PSU transformer (not the 50Hz mains transformer). I was lucky, as we had a NOS spare at work, but not everyone will be so fortunate. Talking of the PSU, I should say that these 'scope run from 24V DC if you wish, so that's handy for getting around ground loop problems and similar.
Moving up the scale a bit, I've an old PM3295 that is 350MHz. The "A" version goes to 400MHz. This does pretty much everything a Tek 2465A does, and does so with a much nicer user interface. The custom Philips ICs and hybrid modules are reliable, and it runs a lot cooler and quieter than the Tek. No problems with obsolete Dallas-style battery-backed RAM because there is a pair of AA cells installed on the real panel! The LCD displays above the rotary encoders show the settings, so you don't have to use the on-screen text readouts, but they are there if you want them. The acceleration voltage is an impressive 21kV, and you hear the EHT rustling up in a way that reminds you of the gold old days of colour CRTs! The trace is much sharper (with 20MHz BW enabled, of course) than anything I've seen before. IIRC, it's only 16kV in a 2465A.
The big problem with Philips test gear in general is the plastics. Luckily not an issue for the PM3215/7 or PM3295 mentioned so far, but when you move forward to the famous PM3055 with the push-button interfaces, these are less likely to be found in good condition. Most problems are cosmetic though. Not everyone likes the pushbutton interface, but I used these scopes extensively in the early '90s and got to really like them. I was happy to find plenty of them here when I joined in the mid '90s. These have extremely good CRTs, using 16kV acceleration voltage. We always said it was a shame that they didn't put that CRT into the older PM3215/7 models, as that would have been the ideal 'scope for people who prefer the more traditional user interface.
I also have a PM3880A Combiscope. This is badged "Fluke" - they'd acquired Philips T&M by this stage - but it's a Philips design. These are great, great 'scopes. The user interface isn't quite as good as the earlier models, but I get on with it just fine. Lovely bright and crisp 16.5kV CRTs. I have one of the lesser models in the range ("only" 100MHz, 2 channels), but 200MHz versions exist. If you get a 4-channel version, be aware that some of them do it in the same, slightly pointless, way that Tek did it with the 2465 and related models, where channels 3 and 4 have a fairly limited range of deflection factors, etc. A 'scope with trig-view (such as the PM3295) has pretty much the same functionality, frankly. So hold out for a version with the fully-featured third and forth channels...
These Combiscopes are proper analogue 'scopes that transform into a DSO at the press of a button. By modern standards, the DSO functionality is a bit basic, but it's something I have used a fair bit, When I bought it, I regarded the digital stuff as a bonus - I needed an analogue 'scope with a reasonable BW and this one came up at the right time. So, I'd equally recommend the analogue-only equivalents. They run cooler, so the temperature-controlled fan would be quieter in normal use (not that my one is terrible by any means). The plastics are a bit better by this point in time too.
My day-to-day 'scope is still my first ever 'scope - the Telequipment DM63. It's only 20MHz, but it occupies less space on the bench than anything else and doesn't have a cooling fan. I know the insides intimately, and they are easy to repair when needed. They have space for 2 vertical plugins, meaning you have have 4 fully-featured input channels - and on the occasions where I need 3 or 4 channels, they do need to be fully-featured. By default, I use one dual plugin plus the V3 differential plugin, which goes down to 50uV/DIV - albeit at a limited BW of course - which is great for investigating low-level problems (bear in mind the massive dynamic range of audio compared to other things like video). It has analogue storage, which is occasionally useful, but in practice I'd be equally happy with the non-storage version (the D63).
I'm not so enthusiastic about other Telequipment 'scopes, however. The visually similar D83 is good for 50MHz, and is usually found with a dual timebase plugin, but it's not as easy to work on, and not as flexible or "special" - there are no shortage of 50MHz dual-timebase 'scopes out there. I've seen many other Telequipment 'scopes that are completely different in construction and style to the DM63, and would pass over them. The DM63 really was the high-point in their output. I own 3 of them! Of course, Tek owned Telequipment at this point in time, and these scopes owe much to the Tek 5000 series (although I'm not actually sure which came to market first, nor who developed the case, etc). The biggest problem with the DM63 is the Tek custom ICs, ironically
Away from those, I have an old HP 1740A as a bit of a background project. Just when I think it's fixed and ready for calibration, another fault crops up. I should give up and walk away, but it sat in the attic for 7 years until I found a parts mule, so it'll have to get done eventually. It's actually quite a nice 'scope, with a pretty nice user interface and good performance. It was the direct competitor to the Tek 465, and a pretty worthy one IMHO. Much, much easier to work on, no fan, no tunnel diodes, crisper display, cheaper to buy because it's not a Tek, etc. I like it.
I bought a Rigol DS1054Z many years back, and have enthusiastically recommended it ever since. But I always point out that such a 'scope does not replace an analogue 'scope - it compliments one. Broadly, the split is as the name suggests; for analogue electronics, an analogue 'scope is usually the best tool, and for digital work, the Rigol does many things that would otherwise be very difficult or indeed impossible with an analogue 'scope. They are so very different in practice that really, DSOs should be called something else. We now have a dozen here at work - and no longer use our Tek DSOs.
