Does old test equipment really ever become truly obsolete?

[AndrewEp17]

I was thinking about how even old oscilloscopes and other equipment from the 90s and even earlier are still used in labs today. And when you think about it, for anything other than cases where you need high sample rates or very high bandwidths, there really isn't a time where older equipment can't still be used today for its intended purpose. It was just a thought i had but i was wondering if anybody else agrees

[tszaboo]

Sure it does. Imagine an old mainframe Communications analyzer, that doesn't support the currently used 4G/5G tech.
You can buy Bluetooth verifiers that don't support BLE for 1/50th the original price.
There are old test equipment that was running Windows XP, that is not compatible with IT policies and have to be replaced just because of that.
Portable spectrum analyzer, with dead battery, no replacement. Or simply worn out connectors.
Or stuff with consumables, that are cheaper to replace to a new unit, lower running cost.

[AndrewEp17]

Yeah you're right. i didn't think about it like that. I quess i was thinking more of like if the equipment still works as it should than for simple measurements its still useful. But yeah you're right there is a lot of equipment that will show its age if they are used today with all technology advancing  and stuff

[Kleinstein]

Old scopes really are obsolete. Even if they still work and could be used the high power consumption and maybe fan noise can be a show stopper.
Similar, old tube based power supplies could well be obsolete - high power consumption and in addition often poor stability.
For private and only very occasional use it may still be acceptable, but than just the space can be an issue.
With some of the old equipment also the safety / EMI can be a show stopper - maybe OK for a museum, but nothing to really use anymore.

Running XP may still be acceptable, there can be things that are worse: I rememer an old instrument that needed an old PC with a standard ISA card - not sure if it would ran with DOS > 4.x. It was a real pain to get data off with a 5 1/4" floppy and a no longer supported early MO disc drive. I rememer a spectrometer that used the TRS80 computer with 8 inch floppy too.

Some equipment gets a rather long life for special uses though. I remember repairing an old tensile testing machine from the early 1940s in about 1998. A crazy mix of old and hacked together upgrades.

[AndrewEp17]

Yeah getting data off of the equipment is another thing i didn't think of. Even if an oscilloscope or something still works, it's not always easy to get data onto modern computers where everything is mostly usb and the equipment uses older connections

[coppice]

There is an immense amount of test equipment which is very specific, and becomes obsolete very quickly. Radio comms testers have been mentioned, and there is a lot of equipment like that, where the protocols they are for go away. However, there is plenty of equipment for things like compliance testing where they might be updatable for minor changes to the compliance specifications, but often have to be totally replaced. Sadly, they are often updatable, but the maker has either died or refuses to support old models, and you still need to replace them.

[AVGresponding]

Old scopes really are obsolete. Even if they still work and could be used the high power consumption and maybe fan noise can be a show stopper.
Similar, old tube based power supplies could well be obsolete - high power consumption and in addition often poor stability.
For private and only very occasional use it may still be acceptable, but than just the space can be an issue.
With some of the old equipment also the safety / EMI can be a show stopper - maybe OK for a museum, but nothing to really use anymore.

Running XP may still be acceptable, there can be things that are worse: I rememer an old instrument that needed an old PC with a standard ISA card - not sure if it would ran with DOS > 4.x. It was a real pain to get data off with a 5 1/4" floppy and a no longer supported early MO disc drive. I rememer a spectrometer that used the TRS80 computer with 8 inch floppy too.

Some equipment gets a rather long life for special uses though. I remember repairing an old tensile testing machine from the early 1940s in about 1998. A crazy mix of old and hacked together upgrades.

This is a very middle class first world attitude. There are plenty of people that can't afford newer, better gear; should they have nothing?

[Kleinstein]

Even in a third world country too high a power consumption is an issue. In many areas electricity is even more expensive there.

The less developed coutries rarely have the old stuff - as they were often even more behind 20 years ago. With more standard instruments like scopes modern ones are not that expensive anymore.
Things like the old mercury standard cells are also very inconvenient to use - so really obsolete. Modern reference and meters make things that much more practical at a relatively low cost.
More special instruments may be used longer, though with some inconvenience, e.g. with an antique computer or "home made" interfaces / adapters.

[Arts]

Old scopes really are obsolete. Even if they still work and could be used the high power consumption and maybe fan noise can be a show stopper.
Similar, old tube based power supplies could well be obsolete - high power consumption and in addition often poor stability.

I have been using my Tektronix 547/1A1 scope for more decades than I care to count. It's a huge, noisy, power hungry shop heater. And I wouldn't trade it for ANYTHING..

Same goes for my Fluke 407D power supply, which is in my soon-to-rebuild pile. Sold my Sorenson 600-1.7 for a bucketload of cash.

And all of my audio equipment is tube based.

I really couldn't care less about electricity rates

[langwadt]

Even in a third world country too high a power consumption is an issue. In many areas electricity is even more expensive there.

The less developed coutries rarely have the old stuff - as they were often even more behind 20 years ago. With more standard instruments like scopes modern ones are not that expensive anymore.
Things like the old mercury standard cells are also very inconvenient to use - so really obsolete. Modern reference and meters make things that much more practical at a relatively low cost.
More special instruments may be used longer, though with some inconvenience, e.g. with an antique computer or "home made" interfaces / adapters.

ye, obsolescent vs. obsolete

[J-R]

I think obsolete is probably a poor term to use, since the definition is a bit broad to begin with.  People apply the term differently.  I'll even admit to throwing it around somewhat loosely in conversation.

Regardless, my opinion is that there is really nothing that is ever truly "obsolete" or 100% garbage.  Even if you think it is, there just might be someone out there who wants it, maybe for parts or just nostalgia.  Whether it is worth your time to get it to them is another topic.

In my case, I have quite a few bits of "obsolete" test equipment and maybe half of it is used as my primary and the other half I bought to repair or just to satisfy my curiosity.  For example, I snagged a Heathkit IM-1212 in excellent condition and the only issue was the original owner neglected to solder one of the switch terminals.  It was fun to find the issue and calibrate it, but it has no other reasonable use case.  But I'll keep it because it's still interesting.

[Gyro]

I'm a bit worried that my meter may be getting a bit long in the tooth - it's reading 3% low after 120 years! 


Edit: Seriously though, I'm still using my old Panaplex display Datron bench DMMs and Philips frequency counter/timer, they are more stable and higher resolution than a a lot of the modern stuff (that I can't justify the cost of buying anyway).

[Fungus]

Some does, some doesn't.

A better question is: Is it worth buying old equipment second hand instead of buying modern gear?

[tggzzz]

I'm a bit worried that my meter may be getting a bit long in the tooth - it's reading 3% low after 120 years! 

Hey! That's older than my calculator.

Test equipment becomes obsolete when either (1) the thing it is measuring becomes obsolete, or (2) it ceases operating effectively.

An example of (1) is waveform monitors for analogue TV/monitor signals.
An example of (2) is unsaturated Weston standard cells.

But many items of TE continue to operate usefully many decades after the manufacturer has stopped making them. Frequently they are better and cheaper than many new TE items. Examples include scopes, DVMs, frequency counters, PSUs.

Of course Sturgeon's Law applies equally to old and new, but the old stuff that people have kept working is more.likely to be part of the 10%.

As ever, good taste and critical appraisal are necessary.

[tggzzz]

Some does, some doesn't.

A better question is: Is it worth buying old equipment second hand instead of buying modern gear?

Easy: it is better to buy good quality used equipment than crappy new equipment. Ditto furniture.

Exception: if the equipment is regarded as disposable.

[AG6QR]

I'm on the board of directors of my local ham radio club.  Ham radio is a hobby for all ages, but it definitely skews toward the older folks, who learned on old gear and sometimes still enjoy using it.  When older members pass away, widows often donate gear to the club, and we get to figure out what to do with it.  We have a few tube testers (these used to be found in the back of any retail store that sold tubes). We have many analog multimeters.  The high-end Simpsons are still useful and sell for a pretty penny; the $7.00 Radio Shack meter from 1978 might still work as well as it did when new, but it's hard to find anyone who wants to use it, since the cheapest digital meter is better in almost every way.

Really old gear, made with vacuum tubes and point-to-point wiring, can almost always be repaired to like-new functional condition.  The circuits are usually relatively simple, and wiring can be probed relatively easily.  Tubes and inductors rarely fail. Resistors and capacitors can be replaced with modern substitutes that often work better than the originals. Schematics are surprisingly likely to be available online (if not in an envelope inside the equipment itself). Old hardware like switches can sometimes be a bit of a problem, but usually not insoluble.

But gear from the early age of integrated circuits is a lot more difficult to repair.  And when software and firmware enter the picture, good luck!

We've got quite a few CRT oscilloscopes.  Early scopes that lack triggering circuitry are like that cheap Radio Shack meter -- even if repaired to work as well as they did when new, nobody wants to use them. They're relegated to being historical curiosities only.

Tektronix scopes from the dawn of the integrated circuit age have custom chips in them, with no readily available replacement sources except other old Tektronix scopes.  Too often, the same chips have failed in several scopes, so cannibalizing is not always practical. In any case, the older CRT scopes are big, heavy, and contain lethal voltages inside, so not every tinkerer would be well-advised to tear one open and fix it.  Most problems with a scope require at least a separate working scope to diagnose and repair.

Older analog oscilloscopes have one advantage over all but the very nicest and most expensive digital scopes:  They work well in X-Y mode.  Specifically, they continuously paint the X versus Y trace, with no interruptions for moving digital data around, no pauses to repaint the screen, no frame rate issues whatsoever.  There are a few cases where that can be very useful.  It can never quite be matched with a digital scope, but a few high-end units can sometimes come close enough for some practical purposes.

[G0HZU]

Some does, some doesn't.

A better question is: Is it worth buying old equipment second hand instead of buying modern gear?

The alternative is to rent new test gear instead of buying it.

For example, the (24 year old) Agilent E4440A PSA spectrum analyser is listed as obsolete by Keysight. To get close to the performance of its RF converter stages with anything new you would still have to pay about $60k or more. The alternative is to rent the new $60k+ analyser whenever the high performance is needed.

The rest of the time you could buy and use a low cost Siglent spectrum analyser if you don't want the baggage that comes with maintaining older test gear like an Agilent PSA analyser.

[tggzzz]

For example, the (24 year old) Agilent E4440A PSA spectrum analyser is listed as obsolete by Keysight. To get close to the performance of its RF converter stages with anything new you would still have to pay about $60k or more. The alternative is to rent the new $60k+ analyser whenever the high performance is needed.

The last time I looked, a long time ago, a rule of thumb was that if you rented something for 10 months then you paid the same as if you had bought it. I.e. monthly rental cost was 10% of the purchase price.

Is that still true?

[G0HZU]

For example, the (24 year old) Agilent E4440A PSA spectrum analyser is listed as obsolete by Keysight. To get close to the performance of its RF converter stages with anything new you would still have to pay about $60k or more. The alternative is to rent the new $60k+ analyser whenever the high performance is needed.

The last time I looked, a long time ago, a rule of thumb was that if you rented something for 10 months then you paid the same as if you had bought it. I.e. monthly rental cost was 10% of the purchase price.

Is that still true?

It probably depends on the item. On my bench at work is a rented Keysight E5080B VNA (4 port 20GHz). I think I've had it about 5 months now. Fortunately, I have no idea how much it is costing a month. Over 5 months I doubt it will amount to 50% of the purchase price though.

[pdenisowski]

I've spent the last 25+ years working for two of the biggest T&M instrument manufacturers.  Based on my experience, the short answer is "it depends"

Some instruments are obsoleted by changing technology:  no one needs instruments to test Token Ring, Frame Relay, ATM, AMPS, WiMAX, etc. anymore. 

And some instruments are effectively obsoleted by advancements in measurement technology:  I can still use a grid dip meter to tune an antenna, but there are MUCH better and cheaper ways to do this now (e.g. NanoVNA).

The only gray area is where older instruments can still perform ... roughly ... the same measurements.  I can use my analog HM407 scope for a lot of basic measurements, and for some of these it is not appreciably worse than a "modern" scope.  But speaking as a hobbyist, I feel that there are much better and much more cost-effective solutions than buying a decades-old analog scope.

[J-R]

Test equipment becomes obsolete when either (1) the thing it is measuring becomes obsolete, or (2) it ceases operating effectively.

An example of (1) is waveform monitors for analogue TV/monitor signals.
An example of (2) is unsaturated Weston standard cells.

But there are still people who could want those items, such as for retro-computing (1), or as a conversation piece to sit on the shelf (2).

[David Hess]

Old scopes really are obsolete. Even if they still work and could be used the high power consumption and maybe fan noise can be a show stopper.

A higher bandwidth older instrument can always show things that a lower bandwidth newer instrument will miss no matter how many extra features the newer instrument has.

For most applications, an old digital storage oscilloscope is just as good as a new one, and digital storage oscilloscopes have been around for 40 years now.

Tektronix scopes from the dawn of the integrated circuit age have custom chips in them, with no readily available replacement sources except other old Tektronix scopes.  Too often, the same chips have failed in several scopes, so cannibalizing is not always practical.

Jim Williams gave the same reason for preferring older Tektronix instruments.

With exception of much later models, those custom Tektronix ICs and hybrids are about the least likely parts to fail.

[EvgenyG]

The only gray area is where older instruments can still perform ... roughly ... the same measurements.  I can use my analog HM407 scope for a lot of basic measurements, and for some of these it is not appreciably worse than a "modern" scope.  But speaking as a hobbyist, I feel that there are much better and much more cost-effective solutions than buying a decades-old analog scope.

HM407 is a great little scope. I've got one too. Yours is in such great condition. Mine came from a Uni lab and is a bit thrashed. I replaced all rotary encoders, fully recapped (136 capacitors!!!) and cleaned it. Still does not look as great as yours, but works well, has a super sharp trace. Nothing beats its AutoSet speed and roll mode is amazing. I also quite like the quick and easy way to change scope modes with presets. I would love to get a HM1507 at some point. It is quite well made inside, fairly easy to service.

I think having one analog scope is good for a lab. I don't see a reason to get more than one unless you're a vintage tech fan or want to open a museum.

Unfortunately, even the HM407 won't see things that any modern high refresh waveform rate scope would easily do.

[Vertamps]

I love electronics, iv bought alot of broken stuff and have spent time fixing for the last 15 years many of boxes. Some that have sat for 5+ years after acquiring. Getting older and making more money, im realizing that some things i should just buy new and be happy with. It depends where you are in your journey. I love my stuff, but id only save 1 or two items in a house fire. I have several professional musician friends that collect music synthesizers. After restoring several dozen vintage synths over the years iv learned if you need something to work for your job, go a buy a new one with a warranty. Vintage synths are cool, and sound great. But i went from $30 an hr to $80 an hr because it was not worth it anymore to restore old gear, my time should be spent on other things LIFE has to offer. Even though i may enjoy it at times, more often i end up cursing the obligation of restoring something. Recycling,melting down, burying and blowing up old stuff is OK. Not everything should be kept forever. Iv got alot of old test gear that im restoring. But to what end? Something is ALWAYS for sale and snickerdoodles my shelves are full, stuff lives on the floor now. Those shining objects with a buy it now button are my sweet horrible addiction.   

[CatalinaWOW]

In my world there are two definitions for obsolescence.

1.  No longer useful for purpose.  This can mean either that the purpose has gone away, or that support in the form of spare parts, cables, etc. are no longer available.

2.  Wildly less useful than current versions of the same product, making it undesirable.

Both of these are a bit fuzzy.  In general the first definition has some element of number of users.   A tiny market of historians or cult users of a product doesn't really qualify as purpose.   So Sinclair and COSMAC computers are obsolete, loss of purpose as are original IBM PCs.  But the entire world of audio enthusiasts is well served by oscilloscopes (from a performance standpoint) from just about any time from the mid-50s on, so I wouldn't call them obsolete based on loss of purpose.  But a range of scopes from the late 70s and the 80s are obsolete because they can't be maintained.

The second definition is where is really hits.  I have a variety of oscilloscopes ranging from 1960s designs up to the present.  And use the newest one almost always.  Because it is small, light and has features that are useful, even though the UI is clumsy relative to many of the classic scopes.  Things like viewing pre-trigger signals.  Decoding serial data.  And others.

Weston cells are another example.  When available they still provide a voltage reference that is far better than most folks really need, so in a sense still suitable for purpose.  But they are no longer available or maintainable.  And far less convenient than packaged standards available today.