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Norman Bernstein
01-26-2018, 12:19 PM
After a long and varied career, our beloved Technics stereo receiver has finally gone to obsolete and nonfunctional electronics heaven.

http://www.marisystems.com/images/technics.jpg

It was born around 1974, and served yeoman duty in our living room, driving a pair of EPI speakers, and fed from a Pioneer turntable.

Sometime in the early 80's, it's FM receiver section was lost, and the unit was relegated to a spare room in our home, driving a pair of Bose 601 speakers, and in 1984, being fed from an early Sony CD player.

In the late 80's, it was assigned to duty with our annual Halloween multimedia extravaganza, driving those EPI speakers hidden in the bushes in front of the house, playing scary music and the sound of lightning and thunder, for the enjoyment of the trick and treaters in the neighborhood.

By 1992, it was retired to my office, driving a set of home-made wall speakers and a large subwoofer, and fed from whatever PC I was using at the time. Around 1998, the vacuum florescent display section died, but it's amplifier was still operational. The unit remained plugged in, and amazingly, was continuously powered on, until 2014, delivering faithful service... without ever being turned off (26 years!)

Around 2014, it was drafted back into service as the source for the spooky music and sounds of lightning and thunder.... only, this time, for the sake of the grandchildren, not my daughters.

After that, it was returned to the office, and was once again called upon to drive the office speakers... and it remained powered on until just last week.

Sadly, a few days ago, the unit finally gave up it's ghost, and has now shuffled off this semi-mortal coil, to join the memories of other old obsolete electronics. Gone, but not forgotten, it will always bring fond memories to those of us who loved it... with our grateful appreciation of its 44 years of service to the family.

R.I.P. :)

Osborne Russell
01-26-2018, 12:28 PM
I just replaced an Onkyo receiver that lasted 28 months, 4 months past the end of the warranty. My 1970 Marantz still works perfectly. Replaced the power switch about twenty-five years ago.

Norman Bernstein
01-26-2018, 12:39 PM
I just replaced an Onkyo receiver that lasted 28 months, 4 months past the end of the warranty. My 1970 Marantz still works perfectly. Replaced the power switch about twenty-five years ago.

It is quite amazing, how long SOME stuff can last.

Most people aren't aware of it.. but typical electrolytic capacitors, the kind commonly used in the power supplies of stuff like this, are normally rated for only 1000-2000 hours of operation. Admittedly, the spec is based on 'stressed' conditions, and designers are normally pretty conservative about the specs and how the part will be used... but it's still pretty amazing.

Of course, a lot depends on the nature of the item. Since things like PC's and cell phones become essentially obsolete within just a few years of manufacture, there's not much incentive to design them for long life... so if they DO last a long time, it's like living on borrowed time. My oldest operational computer is an HP laptop, and I'm pretty sure I bought it no later than 2010... so it's coming on 8 years of life, and in terms of CPU, memory, disk space, and so on, it's well behind the 'state of the art' curve... but it still ticks.

My main computer, however, is one I built about two years ago, from parts... so it's pretty current (Intel i7, 16Gb RAM, twin SSD drives).

Incidentally, I just had to replace a monitor... actually, two monitors, which both died within two weeks of one another. I replaced them with a 32" 4K HP monitor. And was surprised to discover that the DVI-D spec for monitor interfaces, is apparently already obsolete... the new monitor had only HDMI inputs. Fortunately, the Gigabyte motherboard I use has an HDMI video output, and it works perfectly.... 2560 x 1440 resolution. It's a thing of beauty :)

P.I. Stazzer-Newt
01-26-2018, 12:41 PM
Surely that's fixable......

Norman Bernstein
01-26-2018, 12:44 PM
Surely that's fixable......

ANYTHING is fixable. Not everything is worth the effort, though.

P.I. Stazzer-Newt
01-26-2018, 12:46 PM
Think of the fun

nedL
01-26-2018, 12:51 PM
Ahhh, ......... the thoughts of analog music, the tones, the depth of sound, the warmth, ..........ahhhhhhhhhhhh :)

(and I'm not even close to an audiophile.)

Jim Bow
01-26-2018, 01:25 PM
My 1969 Kenwood had a tuning knob the size of a tuna can.

Breakaway
01-26-2018, 01:39 PM
Norm. Did you pick it up and drop it back to the tabletop or shelf a few times? That'll kick start her for some more time. :)

Kevin

SKIP KILPATRICK
01-26-2018, 01:43 PM
I'm guessing that the Bose Wave Radio in the OP photo sitting behind the Technics is about ten to twelve years newer?

Dan McCosh
01-26-2018, 02:04 PM
Does this mean you are going to resurrect the Heathkit?

bob winter
01-26-2018, 02:14 PM
After a long and varied career, our beloved Technics stereo receiver has finally gone to obsolete and nonfunctional electronics heaven.

http://www.marisystems.com/images/technics.jpg

It was born around 1974, and served yeoman duty in our living room, driving a pair of EPI speakers, and fed from a Pioneer turntable.

Sometime in the early 80's, it's FM receiver section was lost, and the unit was relegated to a spare room in our home, driving a pair of Bose 601 speakers, and in 1984, being fed from an early Sony CD player.

In the late 80's, it was assigned to duty with our annual Halloween multimedia extravaganza, driving those EPI speakers hidden in the bushes in front of the house, playing scary music and the sound of lightning and thunder, for the enjoyment of the trick and treaters in the neighborhood.

By 1992, it was retired to my office, driving a set of home-made wall speakers and a large subwoofer, and fed from whatever PC I was using at the time. Around 1998, the vacuum florescent display section died, but it's amplifier was still operational. The unit remained plugged in, and amazingly, was continuously powered on, until 2014, delivering faithful service... without ever being turned off (26 years!)

Around 2014, it was drafted back into service as the source for the spooky music and sounds of lightning and thunder.... only, this time, for the sake of the grandchildren, not my daughters.

After that, it was returned to the office, and was once again called upon to drive the office speakers... and it remained powered on until just last week.

Sadly, a few days ago, the unit finally gave up it's ghost, and has now shuffled off this semi-mortal coil, to join the memories of other old obsolete electronics. Gone, but not forgotten, it will always bring fond memories to those of us who loved it... with our grateful appreciation of its 44 years of service to the family.

R.I.P. :)

Norman, that is depressing news. I am still trying to breathe life into the mighty Marantz. Is possible for electronics to become senile?

skuthorp
01-26-2018, 02:20 PM
I run a 30 year old Rotel amp, a Technics turntable, Wharfdale speakers, Reciver is much newer.

hawkeye54
01-26-2018, 02:21 PM
Norm. Did you pick it up and drop it back to the tabletop or shelf a few times? That'll kick start her for some more time. :)

Kevin

Kevin, that only works if it has reed relays !!!

Rick

hawkeye54
01-26-2018, 02:25 PM
Norman, I bought a similar one in Japan circa 1971, brought it back to California on a destroyer and it lived til at least 2006, I believe one of my kids currently has 'custody' - it may very well still be working . .



Rick

hawkeye54
01-26-2018, 02:26 PM
Norm. Did you pick it up and drop it back to the tabletop or shelf a few times? That'll kick start her for some more time. :)

Kevin

Kevin, that only works if it has reed relays !!!

Rick

ahp
01-26-2018, 02:30 PM
Does it have discrete components, rather than integrated circuits? If so it is fixable.

Norman Bernstein
01-26-2018, 03:05 PM
Does it have discrete components, rather than integrated circuits? If so it is fixable.

There's no difference; it's no more difficult to replace an integrated circuit, as it is to replace a transistor.... especially in legacy electronics, before the lead pitch got so small, where it's difficult or impossible without hot air rework tools (but I have those tools, anyhow). There's no reason, however, to think that it's silicon which has failed... could be a capacitor, maybe a transformer, could even be mechanical in nature (bad switch contact). Regardless, I just don't feel like making a project out of it... I had another receiver available to take its place.


I'm guessing that the Bose Wave Radio in the OP photo sitting behind the Technics is about ten to twelve years newer?

I bought that for my mother, around 2000 or so. She passed away last spring, and nobody else in the family wanted it, so it's taking up space in my office.

John of Phoenix
01-26-2018, 03:20 PM
was continuously powered on, until 2014, delivering faithful service... without ever being turned off (26 years!)

Could that account for the long life? No heat/cool cycle = less stress on the components?

Norman Bernstein
01-26-2018, 03:45 PM
was continuously powered on, until 2014, delivering faithful service... without ever being turned off (26 years!)

Could that account for the long life? No heat/cool cycle = less stress on the components?

That is a raging debate that has been going on for decades.

Cycling power means surge currents.... bad.
Continuous power means constant heat dissipation... bad.

I've been in this business for four decades, and I've yet to see evidence favoring one approach over the other.

If I had to guess, I think I'd favor cycling the power, since it results in less accumulated time while hot... but don't ask me for empirical evidence supporting my supposition.

John of Phoenix
01-26-2018, 03:50 PM
I've wondered about that for a long time. Thanks for settling it. ;)

Osborne Russell
01-26-2018, 04:38 PM
After a long and varied career, our beloved Technics stereo receiver has finally gone to obsolete and nonfunctional electronics heaven.


Obsolete how? My Onkyo had all kind of crap features which, thank goodness for small things, I never even tried to figure out. The Marantz is still here, still working. The Onkyo's on it's way to be crushed and sent back to China as waste . . . whence it came, in a temporarily different form. POS was obsolete when it left the factory.

AndyG
01-26-2018, 07:53 PM
A few months ago, at a local industrial museum, I was touring their display of living rooms of the past. It was a provocative, weird and disturbing experience. The forties room, all dark wood and Bakelite, had items in it that reminded me of my grandparents. The sixties room, full of melamine surfaces, clashing colours, and a tiny monochrome tv, was my childhood. But the (early) eighties room shocked me to the core. For there was MY first tuner/amp, a Sansui T80, my sixteenth birthday present from my parents, placed alongside albums I'd had, and plugged into a turntable and speakers that I'd not.

While my daughter laughed at the analogue tweeness of everything: "look, a top-loading VHS!" I thought "but they've got it wrong".

And then I thought "I'd give anything to hear that thing again, driving my old Wharfedales on bits of chunky bell cable." How would it stand up alongside the NAD and Rogers speakers I bought later? How, indeed, would my current tinnatus and increasing deafness spot a difference?

Tempus fugit, I guess. ;)

Andy

Reynard38
01-26-2018, 07:59 PM
Looks like my old Technics receiver. Played a lot of Rush and Yes with my girlfriend on that.

PhaseLockedLoop
01-27-2018, 01:33 PM
Don’t forget to tear it apart and save those valuable 3055s for some future project.

pipefitter
02-02-2018, 04:27 AM
All my old amps still work. The most abused of the lot, from the "Worst Decade of Audio," a Fisher Studio model, my son is currently using. It has slide controls. I had to clean/lube them before I gave it to my son.

Also have a Scott 150W integrated from the same era that finally has a relay going out intermittently so I retired it. I kept it for the massive heat sink that's in it and the large transformer for perhaps some other DIY amp project. I've collected enough parts to build a few. A Gain Clone, which is a little point-to-point wonder of a simple amp. And also the parts for Nelson Pass's "Amp Camp Amps," among others.

These days, AV receivers end up being worth using just for the additional pre-outs and bass management and auto EQ. Many of the top name, flagship models of the past, can be had for pennies on the dollar and still have years of use in them. Some of these were built like tanks with robust power supplies and amplifier sections. Keep them cool, and choose one with a lot of headroom relative to your listening habits and they should last decades. I have $75 in two Denon AV receivers, one of which who's owner claims his eyes were bigger than his ears when he bought it and the most use it saw was his kids watching Nickelodian. It's 120W into 8ohm and 160W into 4ohms, which is more than double power than I would ever need. My big homemade speakers can get quite loud with just 2-3W. That (most) AVR would not even feel that load.

Electronics are such these days that they obsolete very quickly, at least in spells, just with features alone. When the first owner of the AVR I have bought it 10 years ago, he paid $1200 for it and gave it to me for free because it does not have HDMI. It had been sitting on a shelf in his closet in it's original box for the last 6 years and looks brand new inside and out. Shortly thereafter, I found another just like it in the same shape for $75, stored the same way. So yeah, it is hard to justify rebuilding old consumer grade electronics just for the amount of great used gear still available, if it's the idea of recycling that is driving such ideas.

Free AVR (bottom shelf) and some speakers I built based on full range drivers (https://www.parts-express.com/peerless-by-tymphany-tc9fd18-08-3-1-2-full-range-paper-cone-woofer--264-1062) and two subwoofers ends up being the system to beat, sound quality wise, and was under $200, not counting plywood and my time, of course. The amp on top I splurged on (3000W Behringer pro rig,$230 on sale) and I power all my different subwoofers with since it also has DSP, all controllable via my desktop PC.
https://i.imgur.com/T4HZ1eF.jpg?1

The little full range driver speakers have one 20uF capacitor protecting the top driver that's being used as a tweeter and that's it.

This stuff will probably outlast me, even with 10 years on it by now. I have had it on continuously for over a year by now so it already doesn't really owe anything if it turns to smoke tomorrow.

carioca1232001
02-02-2018, 04:54 PM
That is a raging debate that has been going on for decades.

Cycling power means surge currents.... bad.

Perhaps not that bad, with the soft-turn-on carachteristic incorporated in modern electronic equipment.


Continuous power means constant heat dissipation... bad.

Again, not that bad if one looks at the 'hot-standby iso-frequency transmitter' concept employed extensively on multi-telephone-channel microwave transceptors in frequency-congested regions.

The active transmitters, yes, had a much higher failure rate for whatever reason ( both the active and the hot-standby units put out 1 Watt each, although the former was being constantly FM-modulated with telephone traffic; under normal conditions, the hot-standby unit surrendered it īs power via an isolator-circulator combo to a dummy load, until it was summoned to deliver power to the aerial)


I've been in this business for four decades, and I've yet to see evidence favoring one approach over the other.

If I had to guess, I think I'd favor cycling the power, since it results in less accumulated time while hot... but don't ask me for empirical evidence supporting my supposition.

In a no-load situation, both a power-supply transformer as well as a Class B/C/D amplifier are subject to a modest level of power dissipation.

So when these major components are required to deliver power on-demand, they are probably more in a condition to do so, than if they had just been turned on.

Just guessing.

Norman Bernstein
02-02-2018, 07:32 PM
Perhaps not that bad, with the soft-turn-on carachteristic incorporated in modern electronic equipment.

I can't speak to other types of equipment, but in audio amps, there's no 'soft turn-on' characteristic... at least, not in any schematic I either designed or examined. There ARE usually elements incorporated to minimize speaker pop... but they have no meaningful effect on either power dissipation, or component stress.


In a no-load situation, both a power-supply transformer as well as a Class B/C/D amplifier are subject to a modest level of power dissipation.

Well, sure, the dissipation is modest, in comparison to when the amp is delivering full power... but it's not negligible. Class B amps have a bias circuit which insures a certain amount of dissipation... class A amp dissipation is NOT 'modest', under any circumstances. In Class D, the inevitable amount of full bridge 'shoot-thru' represents dissipation in standby. The power supply transformer (if it's a linear supply), or the inductor in a switching power supply, do indeed dissipate power even when there's no signal. Filter capacitors in any power supply are not 'zero ESR', by any means, and dissipate power.


So when these major components are required to deliver power on-demand, they are probably more in a condition to do so, than if they had just been turned on. Just guessing.

I don't see why there is a difference in component stresses when operating, depending on whether the unit has been continuously powered, or not.

carioca1232001
02-02-2018, 10:02 PM
I can't speak to other types of equipment, but in audio amps, there's no 'soft turn-on' characteristic... at least, not in any schematic I either designed or examined. There ARE usually elements incorporated to minimize speaker pop... but they have no meaningful effect on either power dissipation, or component stress.

The 10-20 dollar power electronics package that operate garage-door electrical motors are equipped with soft-start and soft-stop as standard features; similarly with heavy 3-phase electrical lift motors in a multi-storeyed building.

In the latter case, a much lower monthly bill for electricity as well as a relatively fault-free elevator with speedy but smooth riding characteristics attest to the economics of soft-start electronics (less wear and tear on mechanical parts too).

Perhaps audio electronics manufacturers have no real incentive for similar measures ? Of course, substantially enhanced equipment lifetime could mean longer periods before replacements.



Well, sure, the dissipation is modest, in comparison to when the amp is delivering full power... but it's not negligible. Class B amps have a bias circuit which insures a certain amount of dissipation... class A amp dissipation is NOT 'modest', under any circumstances. In Class D, the inevitable amount of full bridge 'shoot-thru' represents dissipation in standby. The power supply transformer (if it's a linear supply), or the inductor in a switching power supply, do indeed dissipate power even when there's no signal. Filter capacitors in any power supply are not 'zero ESR', by any means, and dissipate power..

Ignored Class A as itīs dismal efficiency gave rise to Class B whose efficiency (Class B) pops up neatly from the analysis as Pi / 4 (78,5%) at full-power (full-swing on load-line superimposed on the I c / V ce characteristic).

A standard power supply transformer is capable of attaining over 95% efficiency at full-power; admittedly, any internal linear voltage regulator (electronic rheostat) within the power supply is a lot less efficient

All-in-all, if left 'on' 24/7, wouldnīt be able to fry an egg over it, unless it contained at least some valves !


I don't see why there is a difference in component stresses when operating, depending on whether the unit has been continuously powered, or not.

In most physical systems, warm-up and cooling-off 'time constants' are generally quite different. Subjecting physical devices to repeated on-off cycling is known to induce fatigue and premature failure. Not totally sure if audio electronics devices are much different in this respect. At least internal combustion engines need warming up prior to subjecting them to full throttle.

Norman Bernstein
02-03-2018, 09:07 AM
The 10-20 dollar power electronics package that operate garage-door electrical motors are equipped with soft-start and soft-stop as standard features; similarly with heavy 3-phase electrical lift motors in a multi-storeyed building.

In the latter case, a much lower monthly bill for electricity as well as a relatively fault-free elevator with speedy but smooth riding characteristics attest to the economics of soft-start electronics (less wear and tear on mechanical parts too).

They certainly do have start-up circuits... but these bear NO relationship to audio amps. The 'soft start' for motors exits for an entirely different set of reasons, having nothing to do with efficiency, and they're only distantly related to 'wear and tear'.


Perhaps audio electronics manufacturers have no real incentive for similar measures ? Of course, substantially enhanced equipment lifetime could mean longer periods before replacements.

We are, to some degree, talking past practical realities here. Modern consumer electronics these days, in terms of useful service life, are really not all that much different than consumer electronics of 20-30 years ago. The typical 'circuit life' (i.e., longevity of the circuits themselves, irrespective of things like mechanical wear of switches, light bulbs, and so on) is vastly longer than pretty much any reasonable expectation of product life. Audio amps, interestingly, might be an exception; the audio amp you use today isn't substantively much better, in terms of perceived audio quality, that the one you might have bought 40 years ago. Not so with TV's, for example, which have undergone multiple technical revolutions in the same period of time. The electronics recycling trailer at my local DPW is FULL of TV's which still work every bit as good as the day thy were bought.... it's just that nobody would want to watch them, compared to a modern high resolution flat panel TV.


Ignored Class A as itīs dismal efficiency gave rise to Class B whose efficiency (Class B) pops up neatly from the analysis as Pi / 4 (78,5%) at full-power (full-swing on load-line superimposed on the I c / V ce characteristic).

Yeah, but we don't listen to sine waves. Average power delivery is often not a great deal more than the dissipation caused by the output stage bias (i it's a calls B amp), or the core loss dissipation (if it's a class D amp).


A standard power supply transformer is capable of attaining over 95% efficiency at full-power; admittedly, any internal linear voltage regulator (electronic rheostat) within the power supply is a lot less efficient

All-in-all, if left 'on' 24/7, wouldnīt be able to fry an egg over it, unless it contained at least some valves !

All of this is true... although the 'theta junction to case' (sorry, too lazy to insert the Greek characters) is often a pretty high number, so the heat you perceive on an exposed heat sink is nothing like what the semiconductor junctions are experiencing. Fortunately, those IC's can easily take that heat, without negative effect on their expected lifetimes. The only components that one would need to worry about would likely be aluminum electrolytic capacitors, and possibly some inductors, especially, inductors used in class D output bridges. I spent a considerable amount of time, two years ago, trying to solve the problems of inductor heating due to core loss, in an application using a 400 watt Class D audio amplifer chip... it's a very had problem to solve. Those inductors, by the way, are heating whenever power is turned on... even when there's NO signal.


In most physical systems, warm-up and cooling-off 'time constants' are generally quite different. Subjecting physical devices to repeated on-off cycling is known to induce fatigue and premature failure. Not totally sure if audio electronics devices are much different in this respect.

Well, that is the debate, in a nutshell... and there's no clear answer. The 'fatigue' resulting from cycling power is primarily caused by inrush currents into filter capacitors, when an amplifier is first powered up... so, reliability is a function of the ability of those caps to withstand the inrush currents. As a designer, you can specify better capacitors... which, naturally, cost more... so it's an economic tradeoff.

For constantly powered systems, the issue is whether constant heating of some components accelerates their failure rate. These things tend to have grossly linear behavior; the longer the component spends being heated, the shorter the life span. 20 or 30 years ago, the threat was the 'drying out' (really, the slow outgassing) of the dielectrics used in aluminum electrolytic capacitors. I think the'e much better these days, fortunately.

The good news: if a piece of gear makes it through the infancy failure curve, it's likely to last a VERY long time.

Ted Hoppe
02-03-2018, 11:33 AM
can I send this one to you? It's not blue tooth compatible either.

https://i.pinimg.com/originals/a1/be/0a/a1be0a577f2e98c05200b00383b3151c.jpg

P.I. Stazzer-Newt
02-03-2018, 11:42 AM
You can send it here.

Very Very decorative.

Ted Hoppe
02-03-2018, 12:31 PM
You can send it here.

Very Very decorative.


Yes - very decorative. And fun if into it. Would make cool accessory for man cave or batch pad. Wife of mine is making me clear out old stuff including hundreds of vinyl. Got rid of my old tube receiver last year.

Sadly- It would cost as much to send as you could buy local.

ccmanuals
02-03-2018, 12:52 PM
My first reel to reel I bought in the early 70's in Incirlik, Turkey. It was a beauty that I paired with an Onkyo receiver and Sansui speakers. Long gone now.
https://www.hifiengine.com/images/model/sony_tc-377_stereo_tape_deck.jpg

P.I. Stazzer-Newt
02-03-2018, 12:55 PM
Had a lot of fun with a TC377 - loved the separate record switches.

willmarsh3
02-03-2018, 03:32 PM
That's pretty good longevity for a receiver.

I bought a Pioneer SX-3600 receiver around 1980 back in the day when I considered a stereo system was the cat's meow. It was quite heavy. Around 1990 or so it died. I replaced it with an Adcom tuner and amplifier. A few years later the tuner stopped receiving FM. As time went by I sort of lost interest in this. The speakers deteriorated. I eventually lost interest.

I do find the Techmoan youtube channel interesting since it shows the history of audio equipment and electronics, how it is constructed, how it works and what role it played in its hey day.

carioca1232001
02-03-2018, 10:08 PM
can I send this one to you? It's not blue tooth compatible either.

https://i.pinimg.com/originals/a1/be/0a/a1be0a577f2e98c05200b00383b3151c.jpg

As a young boy, tape-recorders had me mesmerised ! In ī62/ī63 my father purchased a Grundig TK-46 from Selfridges (in London) and had it shipped to Karachi at my behest !

Shortly thereafter a school chum was to show me an Akai stand-up tape-recorder at his home that his father purchased on a trip to Hong Kong.

The sound of the Akai, specially when reproducing pre-recorded tapes, was simply phenomenal, the Grundig TK-46 was nowhere near.

John Smith
02-03-2018, 10:32 PM
I'm not sure how long I've had my Optimum (radio shack) receiver, but it's been a LONG time. It as the same exact dials, buttons, jacks, and connectors my mom's neighbor's Fisher unit of the same time had. Same specifications.

Now that I've typed this, it will likely die on me tomorrow.

Breakaway
02-04-2018, 12:55 AM
I'm not sure how long I've had my Optimum (radio shack) receiver,

I thought, " Realistic," was the Radio Shack house brand?

Kevin

Donn
02-04-2018, 01:08 AM
Optimum was a Sherwood model.

carioca1232001
02-04-2018, 09:53 AM
They certainly do have start-up circuits... but these bear NO relationship to audio amps. The 'soft start' for motors exits for an entirely different set of reasons, having nothing to do with efficiency, and they're only distantly related to 'wear and tear'.

In an institution where J.A. Fleming discovered the diode valve effect despite his extensive resaerch in all facets of electrical machines - '50 years of electricity' authored by Fleming sat on my (deceased) father-in-laws bookshelf, himself an engineer, in Rio de Janeiro - the Electrical Machines Laboratory on the 6/7 th floor (canīt recall exactly) was simply dismantled and huddled away in the late 1980`s !

AS for the electrical/electronic dichotomy that progressively preyed on the curriculum as it unfolded over the duration of the course, one result is the insensitivity shown to the plight of electrical-motors being slammed with rated voltage in some drive-motor apps ('start-stop', from minute to minute, non-stop)


We are, to some degree, talking past practical realities here. Modern consumer electronics these days, in terms of useful service life, are really not all that much different than consumer electronics of 20-30 years ago. The typical 'circuit life' (i.e., longevity of the circuits themselves, irrespective of things like mechanical wear of switches, light bulbs, and so on) is vastly longer than pretty much any reasonable expectation of product life. Audio amps, interestingly, might be an exception; the audio amp you use today isn't substantively much better, in terms of perceived audio quality, that the one you might have bought 40 years ago. Not so with TV's, for example, which have undergone multiple technical revolutions in the same period of time. The electronics recycling trailer at my local DPW is FULL of TV's which still work every bit as good as the day thy were bought.... it's just that nobody would want to watch them, compared to a modern high resolution flat panel TV.

One always learns something here ! Thanks too for the other comments in your post above.