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-   -   Progress in electronics (https://www.vintage-radio.net/forum/showthread.php?t=157895)

woodchips 9th Jul 2019 9:50 am

Progress in electronics
 
Some more philosophical thoughts, sorry.

Sorting, and was looking at an HP 8690B sweep generator. When first made it used backward wave oscillator tubes, needing a 1000V sweep voltage waveform. My unit was made, from component date markings in mid 1977.

Next to it was one of the mobile phone radio comms analysers, ISA buss, Pentium CPU, several DSP56001's, and that was dated about 1997.

This is just 20 years. From valves in the 8690B to processors running at 130MHz. Just how did we keep up? Did others end up with burnout. I went working for myself, PIC microcontrollers from 56116 DSP with the data sheet timings in fractions of a ns.

What about TV repairs? Going from 405 lines at 70MHz to 625 line colour at 800MHz in the 80's, did people who repaired TVs also just walk away?

The strangest thing of all is that now the 8690B is actually more use than the comms analyser, it can be repaired. My unit has the later YIG oscillator plug in, not the BWO, the analyser won't boot, won't work, just junk.

Radio Wrangler 9th Jul 2019 10:08 am

Re: Progress in electronics
 
I'd have been sitting about 100 feet away when that 8690B was built.

They were kept in production for a very long time after other models had taken over, just to keep customers happy who had them written into their test procedures

THe 8690 ran from 1966 and the solid state 8620 came out in '71

http://hpmemoryproject.org/wb_pages/wall_b_page_10d.htm

I was working on a microprocessor controlled RF instrument at HP from '74 onwards. So in not much physical space there were valve-mechanical instruments, their solid state replacements in manufacture ad processor controlled stuff in development.

The pace was fairly hot, but it was great fun.

As a young engineer, there were some superb people there to learn from. I tried to make the most of the opportunity.

David

Nuvistor 9th Jul 2019 11:17 am

Re: Progress in electronics
 
I didn’t find TV repairs going from 405 70 Mhz to 625 colour at 800Mhz a problem, really enjoyed the work. I did leave but not due to the technology but I found a better paid job with digital computers, another challenge that enjoyed.

I was a lot younger then and enjoyed learning and the challenge, technology seems to be leaving me behind now.

Maarten 9th Jul 2019 1:09 pm

Re: Progress in electronics
 
Quote:

Originally Posted by woodchips (Post 1158972)
What about TV repairs? Going from 405 lines at 70MHz to 625 line colour at 800MHz in the 80's, did people who repaired TVs also just walk away?

I don't know about 405 lines, but at every change to a new technology (transistor, colour, flat) some repairmen don't keep up.

Red to black 9th Jul 2019 9:51 pm

Re: Progress in electronics
 
I suppose if you tried to jump straight from say a valve 405 B&W set and associated technology to a modernish 1990s widescreen set in one go the learning curve would be extremely steep and most likely a step too far.

However I found personally the technology was gradually evolutionary rather than revolutionary for the most part, one or two exceptions might have been from vacuum devices to solid state and B&W to colour.
Even here though the technology was generally introduced in stages, in the first instance with Hybrid sets, and FM stereo had some technology in concept at least with colour.

I personally missed the valve era completely, only caught a glimpse at the back end of hybrid sets due to my age.

Most new chassis followed on from the previous one with more highly integrated circuits coupled with excellent circuit descriptions in the manuals to help with the newer technology parts, and as I say was mostly just a step change up in a series of small steps so we were able to keep up.
One or two exceptions occurred along the way such as the Sharp CS chassis for one which used class D output stages using tiny transistors, this was a steep learning curve at the time ;D

Service modes were not too bad either, because again we started with the ITT digivision (the comprehensive manual was a massive help here), to setting the enabling option at byte level in the Salora, Hitachi and certain Turkish Bush sets of the day, and each newer generation took the concept a step further forward and in complexity each time, so again the learning curve was not too steep, we were standing on the shoulders of giants so to speak.

We took VCRs, CD players and satellite recievers in our stride, again each newer model being more advanced and more integrated than the one before.
Camcorders were a bit specialist for most of us in the trade unless the faults were fairly simple and did not need specialist and expensive jigs/test equipment, the compact nature of these products did not help either.

It all really changed with the advent of flat panel sets and digital receivers/technology, here there were no more circuit descriptions, barely any circuit diagrams, and replacement panels/circuit boards being the order of the day, the component density and any theory behind the inner workings were probably more than us mere mortals could ever understand, even if the makers told us how they worked.
You also really needed manufactures technical help too, which we independents did not have easy access to.
This really was a step too far.
Yes we could repair some faults still down to component level, it was just this was becoming increasingly economically unviable.

Edit: I know there are some members here whom started with 405 line valve technology and have/are still working on modern products to this day, they have adapted/learned more than I will ever know :thumbsup:

Graham G3ZVT 10th Jul 2019 2:03 pm

Re: Progress in electronics
 
None of us got rich working as a TV rental repair tech, but as each new innervation came out there was the possibility of a slightly higher pay grade.

Sounds daft now, but I remember the EEPTU union arguing with Granada TV Rentals management over a pay rise before we would repair remote control faults, when we first started to offer them around 1973.

evingar 10th Jul 2019 2:31 pm

Re: Progress in electronics
 
Quote:

Originally Posted by Maarten (Post 1159015)
Quote:

Originally Posted by woodchips (Post 1158972)
What about TV repairs? Going from 405 lines at 70MHz to 625 line colour at 800MHz in the 80's, did people who repaired TVs also just walk away?

I don't know about 405 lines, but at every change to a new technology (transistor, colour, flat) some repairmen don't keep up.


I remember a conversation my mum had with a repair man that came to fix our rented valve B+W TV.
Must have been early 70s and she mentioned upgrading to colour. The bloke said he would never touch the things. A year or so later we made the switch and about 6 months after that the thing stated fizzing and crackling - guess who came out to mend it ? :-)

G6Tanuki 10th Jul 2019 2:54 pm

Re: Progress in electronics
 
I was never into TV repairs, but _do_ remember the time in the mid-1980s when the first PC-based logic-analysers appeared on the scene and I realised that the new logic-analyser I was using (with its 8086 CPU and separate Z80-based display-controller, and a massive 320Kbytes of RAM) was actually more-powerful than the five-year-old DEC LSI11/23-based piece of gear I was using the analyser on!

John10b 10th Jul 2019 6:56 pm

Re: Progress in electronics
 
This topic got me reminiscing about my working life and all that went with it, the good the bad and the ugly, from side connections on valves, am/fm, stereophonic sound, black and white tv to colour tv, transistors, chips, surface mount components, Digital tv, Apprentice Training, Health and Safety, Management, and that excludes the Industrial Electronics part of my career, which is a completely different story. It’s been very interesting and I’m still learning or should say refreshing my memory, which is why I so enjoy forums like this, and restoration of old Radios and Record Players in my shed.
That’s just a quick snap shot of my career.
Cheers
John

red16v 10th Jul 2019 7:36 pm

Re: Progress in electronics
 
I was at the other end if you like, working for one of the national broadcasters. When I retired about 7 years ago we were well into the digital age and IT was beginning to make significant inroads. In the end, for me, the speed of implementation of IT solutions to tv production was lightening fast - too fast for me and that’s why I eventually retired. The speed of the transition from digital signal processing to ‘pure’ IT was just phenomenal. When I see former, younger, colleagues nowadays to be honest I simply don’t comprehend what they are even talking about in terms of signal processing. The ‘go to’ engineer to ‘old duffer’ in the space of 35 years, a familiar story to many here I’m sure! No regrets, I enjoyed every minute of it.

ionburn 10th Jul 2019 7:44 pm

Re: Progress in electronics
 
Interesting how one of my first repair jobs, when I was still training, was a vibrator powered car radio. I don't remember much about it except that I was told at the time I shouldn't have bothered.

I am always surprised by the fact that something that may have been hard work to sort in past years becomes so much easier as time progresses. An example being working at VHF and even UHF frequencies. Ok it's still something that requires thought but maybe not the dark art it once was.

There are things I prefer but I use whatever I have (or can easily aquire) that work. Ride the wave lol.

'LIVEWIRE?' 10th Jul 2019 9:04 pm

Re: Progress in electronics
 
I started out professionally in 1971. The first 11 months of that year were spent at Letchworth G.T.C., being taught from basic principles through to Setting up, but not servicing Colour TVs. Whilst most of my fellow trainees went on to become TV field Engineers, I worked from December 71 till the firm closed in April 95 for an Auto-Electrical firm as their I.C.E. (Car Radio) service engineer. Vibratior powered Radios were by then obsolete, but I still recall repairing a few, along with several Philips Auto-Mignon Car record Players, 8 Track Cartridge Players, Cassette Players, and, towards the end of that time, In-car CD Players. Along the way, the radio side went from MW/LW mono to FM , then FM Stereo. DAB didn't arrive until several years after I'd left the trade. Over those years, and since, I've serviced & repaired many makes including Radiomobile, Motorola, Autovox, Philips, PYE, EKCO, Blaupunkt, Clarion, Pioneer, Sharp and Sanyo (the latter mostly being two models re-badged as Radiomobiles)

SiriusHardware 10th Jul 2019 10:53 pm

Re: Progress in electronics
 
In some cases now it's not just about being willing to learn or change - we are getting to the point where electronic parts are becoming so small that they are almost beyond the ability of humans to handle or solder them and they don't even print the values on them because they would be unreadably small.

Non- electrolytic SMD capacitors haven't had the values marked on them for a while, but now they have been joined by unmarked resistors as well. The present generation of SMD passive parts is so small that soldering one by hand is like trying to solder a grain of coarse sand into place.

Add to this, ICs which no longer have their pins exposed on the side of the device, but have them on the bottom making them much harder to line up and solder. The most notorious of these are BGA (Ball Grid Array) devices, but even relatively nondescript devices with a low pin count now tend to come in pinless packages.

I see the end of my long career as a repair technician looming ever closer.

Maarten 11th Jul 2019 12:25 am

Re: Progress in electronics
 
Pinless packages are not that big of a problem in my opinion. At least when they're small enough as you can just use a hot air station which isn' more expensive or harder to operate than a normal soldering station. You just have to use a microscope.

On the other hand, larger BGA chips require special equipment to handle which is harder to operate and more expensive.

For those interested, the youtube channels of Louis Rossmann and iPadRehab are useful to learn more about practical microsoldering.

SiriusHardware 11th Jul 2019 12:34 am

Re: Progress in electronics
 
The main problem I have with pinless fine-pitch ICs is placement.

When the IC is roughly in position you literally can not see where the IC contacts are in relationship to the PCB pads, you can only hope and pray that the screen printed outline around the IC is a reasonably accurate guide to where to plant it.

When the pins or contacts were on the side, you could at least see whether they were lined up.

IanBland 11th Jul 2019 5:00 am

Re: Progress in electronics
 
The last time I tried to find somebody to repair a CRT monitor, I couldn't find anybody in my town or practicably nearby who was prepared to work on it. That was before I found this forum (I actually found this forum due to a faulty subsequent monitor which thanks to help from McMurdo and others I was able to return to functioning condition). It was like all the knowledge of CRTs literally had vanished from the economy.

'LIVEWIRE?' 11th Jul 2019 8:29 am

Re: Progress in electronics
 
No doubt the reasons for the disappearance of repair workshops are encapsulated in several of the above comments. Things are just not made to be economically repairable any more!

Andrew2 11th Jul 2019 9:30 am

Re: Progress in electronics
 
I entered the TV repair trade in 1969 as colour was moving in. A lot of the older engineers were getting out because they felt they couldn't handle the more complex CTV's. I had done mono TV at college but not colour, so I was self-taught be way of library books and a part-time course at college. I still have my copy of 'Principles of PAL Colour Television' by H.V Sims.
All great fun and I enjoyed it. We service people just seemed to adapt to new stuff as it came along - things like video recorders and CD players just sort-of 'soaked in'. None of it was difficult if you had an interest and understood the basic principles.

AC/HL 11th Jul 2019 11:44 am

Re: Progress in electronics
 
The exponentially rising appetite for features and innovation versus the competing evils of labour cost and selling price. Lamented and resisted by many, but demanded by the wider "market".
It started with crystal sets and shows no sign of ending any time soon. When I was at school, if someone had said that I'd carry a wallet sized device that can find anywhere in the world, look up a lifetime's knowledge instantly and potentially enable me to talk to anyone on the planet I'd have laughed. Throwaway now. Oh, and it's a torch too!

Radio Wrangler 11th Jul 2019 11:53 am

Re: Progress in electronics
 
Back when we were at school, what they were predicting about our future had us in jet packs and spaceships, taking holidays on Mars by now, with the family robot along to help.

Prediction of the future has always been rather spotty. One computer-per-spaceship was enough for both Clarke and Roddenberry.

David


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