There's no substitute for doing things yourself. It may be re-inventing the wheel, but you get to know what tricks & fudges might have been made to get the wheel to work. Its the best method of learning.
I find, too, that I can read something in a book, I might remember the gist of it later or I might not. But if I do it myself in my own lab, I'll remember ALL the details, for years and years after. And I'll know subtleties that they didn't bother to put in the book.
Oh, not necessarily, not for the factory or R&D engineer. Even before 1948 there were automatically controlled instruments with a processor converting the data into graph plots.
The instrument controller and recording processor at the R&D lab where I worked was called "Young Keit the trainee tech." It was actually more sophisticated than these modern processors, because the engineer programmed it with standard conversational English and/or actual demonstration.
The instrument controller and recording processor at the R&D lab where I worked was called "Young Keit the trainee tech." It was actually more sophisticated than these modern processors, because the engineer programmed it with standard conversational English and/or actual demonstration.
How about testing a bunch of tubes, and creating a graph with a family of plate curves . . .
using nothing but adjustable power supplies, and giant Weston current and voltage meters that had mirrored scales . . . Oh, did I say in the 1930s.
Nothing like a more modern curve tracer and computer.
using nothing but adjustable power supplies, and giant Weston current and voltage meters that had mirrored scales . . . Oh, did I say in the 1930s.
Nothing like a more modern curve tracer and computer.
I also use old Tek and Philips measurent equipment. Never any issues with these. I worked for EWB and NI as “senior AE” here in the Netherland about 12 years ago.
In general all top measurement equipment you can find here is in working condition and need only some calibrating and cleaning of the contacts. No smoke residues to remove. My guess is that here these units were even more costly ( import) and used for medical or military labs. Also here the rule of thumb is to replace equipment after 5 or ten years even it is in perfect condition.
In general all top measurement equipment you can find here is in working condition and need only some calibrating and cleaning of the contacts. No smoke residues to remove. My guess is that here these units were even more costly ( import) and used for medical or military labs. Also here the rule of thumb is to replace equipment after 5 or ten years even it is in perfect condition.
Curve tracers go back further than you might think. At the R&D lab I worked in as a trainee, they had a pre-World War 2 curve tracer made by Siemens & Halske in Germany. It had a large display CRT, about 6 to 7 inch as I recall, with a long persistence phosphor. The company photographic section had a method using high contrast film to make nice looking graphs from photos of the display, complete with major and minor grid lines added in the photographic process.
We also had a couple of late 30's era English Cossor double beam CROs (true double beam, not beam switched). They were poor in bandwidth, good for audio only, but they were very accurate. By means of "back-off" controls, like an old-fashioned precision voltmeter, you could measure the voltage at any point in the waveform to within 2% or so of any other point. They also had a fairly long phosphor persistence, so if you wanted to examine the distortion of deep bass frequencies, you could do it much easier than modern CRO's, at least until Tektronix came out with bistable storage in the late 1950's.
Gee, that magazine is a collection of gimmicky stuff obsolete even well before 1948, plus articles copied from British and Australian publications.
I laughed when I saw the FM radio. The circuit's fine, but the USA based Gernsback copied it from the applications journal of the Australian tube maker AWV. AWV in turn took it from an American RCA application note. AWV published it purely for technical interest - FM broadcasting didn't start in Australia until 1977. Gernsback were apparently unware that they could have got it direct from RCA.
(There were a couple of low power community FM stations in Australia before broadcasting officially started - listener numbers were insignificant. However AWV's parent company AWA did make FM receivers for export only - for the European market. No other Australian manufacturer made FM radios.)
Not to hijack the OP regarding DC coupling design, and I apologize, I just wanted to mention that indeed, TE/HP vintage equipment are good and "cheap".
But they are old and will fail soon (mechanical failure, tantalum caps etc etc..)
So I looked around and I just ordered a PC Oscilloscope, Data Logger & RF Products | Pico Technology USB device.
Plotting a Db/THD frequency response by hand takes quite some time. I did 6 in 4 hours 3 days ago, PITA.
It seems that with these products, and the enormous calculation power of a simple PC, you can extract all the data you need and have a plot drawn in real time .
I also wanted something faster, not costing a leg and arm, not to mention saving bench space to.
Maybe someone using these equipment should start a thread. I might when I get mine and know its capabilities.
Cheers.
But they are old and will fail soon (mechanical failure, tantalum caps etc etc..)
So I looked around and I just ordered a PC Oscilloscope, Data Logger & RF Products | Pico Technology USB device.
Plotting a Db/THD frequency response by hand takes quite some time. I did 6 in 4 hours 3 days ago, PITA.
It seems that with these products, and the enormous calculation power of a simple PC, you can extract all the data you need and have a plot drawn in real time .
I also wanted something faster, not costing a leg and arm, not to mention saving bench space to.
Maybe someone using these equipment should start a thread. I might when I get mine and know its capabilities.
Cheers.
Brice,
Oh, I contributed to the hijack a while ago. It's all good fun and learning...
I think old Tektronix & HP storage CRO's should be avoided. The CRT's had a limited life, and they can't be replaced. And modern solid state microprocessor based oscilloscopes do the job far better, and usually have a spectrum analyser function as well. And they do take up a lot less bench space, which is important, just as you said. Bench space is like money - the more you have, the more you seem to need... Now, if only I had extendable arms....
Apart from storage CRO's (non-storage CROs are ok), I disagree with you re old equipment. Vacuum tubes can be replaced with NOS. Carbon composition resistors are still available. Old Tek and HP gear was made very mechanically robust. I've never seen a transformer in old Tek & HP gear fail.
Folk that restore old tube radios, stereos and the like, often replace all capacitors as a standard course. This is neither necessary nor desirable with professional audio nad neither necessary nor desirable in lab-grade instruments.
Especially in old tube-based Tektronix gear, the electros are high grade professional units, very different in life to those used in consumer electronics. Not only did they use professional grade paper/polyester capacitors, again much better than consumer grade, they mostly designed the circuits so a mild amount of leakage simply doesn't matter. Recently I restored a 1950's era Tek 130. Not only do the caps have no measurable leakage, the circuit design ignores several microamps. In a radio coupling capacitor, that would be disastrous. Old test gear typically runs a lot cooler than consumer gear, further increasing component life substantially. Tubes are run well inside their ratings, so they last a very long time, and the circuits are extremely tolerant of low emission anyway.
The Tek 130 uses several 6U8 triode pentodes. These didn't last all that long in TV service. Just to see, I tried some old ex-TV 6U8's that have only about 10-15% emission. The Tek 130 operation and calibration was completely unaffected.
My old Tek tube-based instruments are around 50-60 years old. They'll still be good in another 50 years, if I live that long - which is unlikely, given I am over 75.
Oh, I contributed to the hijack a while ago. It's all good fun and learning...
I think old Tektronix & HP storage CRO's should be avoided. The CRT's had a limited life, and they can't be replaced. And modern solid state microprocessor based oscilloscopes do the job far better, and usually have a spectrum analyser function as well. And they do take up a lot less bench space, which is important, just as you said. Bench space is like money - the more you have, the more you seem to need... Now, if only I had extendable arms....
Apart from storage CRO's (non-storage CROs are ok), I disagree with you re old equipment. Vacuum tubes can be replaced with NOS. Carbon composition resistors are still available. Old Tek and HP gear was made very mechanically robust. I've never seen a transformer in old Tek & HP gear fail.
Folk that restore old tube radios, stereos and the like, often replace all capacitors as a standard course. This is neither necessary nor desirable with professional audio nad neither necessary nor desirable in lab-grade instruments.
Especially in old tube-based Tektronix gear, the electros are high grade professional units, very different in life to those used in consumer electronics. Not only did they use professional grade paper/polyester capacitors, again much better than consumer grade, they mostly designed the circuits so a mild amount of leakage simply doesn't matter. Recently I restored a 1950's era Tek 130. Not only do the caps have no measurable leakage, the circuit design ignores several microamps. In a radio coupling capacitor, that would be disastrous. Old test gear typically runs a lot cooler than consumer gear, further increasing component life substantially. Tubes are run well inside their ratings, so they last a very long time, and the circuits are extremely tolerant of low emission anyway.
The Tek 130 uses several 6U8 triode pentodes. These didn't last all that long in TV service. Just to see, I tried some old ex-TV 6U8's that have only about 10-15% emission. The Tek 130 operation and calibration was completely unaffected.
My old Tek tube-based instruments are around 50-60 years old. They'll still be good in another 50 years, if I live that long - which is unlikely, given I am over 75.
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Hi Keith,
I agree with you for old tube tek. These are fixable. My equipement is from the 90's, so full of ICs, transistors etc... No processors. I looked inside the distortion analyser and it is really complex and packed. A lot of tantalum caps and other goodies.
I don't feel like spending hours trying to fix it when this happens and will happen. That is why I am looking for an affordable digital solution as a backup.
Don't get me wrong, I love my TEK gear. It's accurate, very well design and reliable.
But time alone takes it toll on all, well, not one wine
I agree with you for old tube tek. These are fixable. My equipement is from the 90's, so full of ICs, transistors etc... No processors. I looked inside the distortion analyser and it is really complex and packed. A lot of tantalum caps and other goodies.
I don't feel like spending hours trying to fix it when this happens and will happen. That is why I am looking for an affordable digital solution as a backup.
Don't get me wrong, I love my TEK gear. It's accurate, very well design and reliable.
But time alone takes it toll on all, well, not one wine
I bought my first piece of Pico Tech sometime more than 20 yrs ago, an ADC-100. 2-channels, just audio but has both scope & SA. Connected to a PC thru a Centronics printer cable. It ran in DOS, never got it to run on anything higher. Got it out last spring, still runs OK.
Others are as follows
ADC-216 16 bit, so 96db capable, scope & SA, 2-channel. About 40 KHz. Pico 3224, 12 bit so 72 db. 2-channel, 10 MHz. I use it most of the time.
Pico 5203, so 200 MHz, 2 channel with an ARB on board. Many waveforms built in. Can change resolution in 1/2 bit steps.
I found it possible to run both the 3224 & 5203 on the same ACER laptop running WIN XP. The note I'd got from Pico sometime before that said probably not. So tried anyway, success!!
Gave away my R&S analogue scope about 10 yrs ago. It was 2 channel, 100 MHz. AGs are HP 200CD, GW GAG210 & a home grown Bridged-T type with the Bill Hewlett light bulb in the FB loop. An HP 334A for THD measurements, it was USAF surplus, still has their sticker on the front panel.Also an HP 651A RF Gen, OK to 10 MHz.
VMs are two of MetraHit 29S, Precision DVM & Power meters. Measure real power directly. And two of what we would call ordinary DVMs. Also a couple of analogue VOM meters, one of them auto ranging. Gave away an HP 302 Wave Analyzer & HP 606A RF Gen. Took up too much bench space.
With regard to Motorola, here at their Toronto operation the production & development area looked like an HP showroom. A very good account for us. Much later the last sales I made to Mot were a couple of Aeroflex 3920 Comm Analyzers. A very nice piece of gear, many functions on board. The OS is WIN XP, the HD is SS.
Attachments
I bought a HP 339A distortion analyser on eBay, about $100. Seller said they were liquidating husband's estate. Sold As Is, no idea how to test it. Photos looked clean, so I figured worst case, I get some parts to fix up another one. It arrived in perfect condition - no a thing wrong with it. Easily met factory specs.
I bought on eBay several items sold as "Tested, works well". These all arrived inoperative or not working well. Maybe "Tested, works well" means "I plugged it in and a light came on." But they were all easily fixed.
We in Australia have a problem with eBay though. Sometimes the shipping costs from the USA are ridiculous, without rhyme or reason. I needed a diecast box, 1" x 1" x 2" for a special project. These are not stocked in Australia. I tried one US-based seller - quoted cost $7.20 for the box and $85 for shipping. Tried another US seller - $8.10 for the box and $35 for shipping. I bought locally a 4 x 2 x 1 box ($12), cut half an inch off each end, and epoxied the 2 ends together. Yet I bought a power cord for an old Tek instrument from a US seller - was about $12 plus $7 for postage. Trump says he's going to make America great again. He needs to fix the shipping costs. Shipping from China is nearly always free, or just a few dollars - and it gets here quicker.
I bought on eBay several items sold as "Tested, works well". These all arrived inoperative or not working well. Maybe "Tested, works well" means "I plugged it in and a light came on." But they were all easily fixed.
We in Australia have a problem with eBay though. Sometimes the shipping costs from the USA are ridiculous, without rhyme or reason. I needed a diecast box, 1" x 1" x 2" for a special project. These are not stocked in Australia. I tried one US-based seller - quoted cost $7.20 for the box and $85 for shipping. Tried another US seller - $8.10 for the box and $35 for shipping. I bought locally a 4 x 2 x 1 box ($12), cut half an inch off each end, and epoxied the 2 ends together. Yet I bought a power cord for an old Tek instrument from a US seller - was about $12 plus $7 for postage. Trump says he's going to make America great again. He needs to fix the shipping costs. Shipping from China is nearly always free, or just a few dollars - and it gets here quicker.
Hey chaps, Keit is not Keith, but you can call me Keith if you want. Keit is short for Keitan, pronounced as in "Kite-an". Therefore "Keit" should be pronounced as in "Kite" - a thing that flies, and not the pronounciation of "Keith", which is as "Keeth". In Australia, though, chaps invariably get called by their nicknames.
I've never bought anything from the Philippines. I hope your post office is one of the smart ones and not like the US post office.
Postal authorities in almost all countries are in financial trouble because email and SMS texting has pretty much killed off letters. The US post office appears to have reacted to this by closing large numbers of local post offices and by dramatically putting up their postal charges. In Australia, our postal authority was smarter - they reacted to the big loss of letter income by:-
a) converting local post offices into stationary, office supply, and trinket stores, as well as traditional postage functions. With the broader product range they can keep them all open.
b) taking a longer time to deliver
c) acting as a one-stop-shop to pay bills.
I've never bought anything from the Philippines. I hope your post office is one of the smart ones and not like the US post office.
Postal authorities in almost all countries are in financial trouble because email and SMS texting has pretty much killed off letters. The US post office appears to have reacted to this by closing large numbers of local post offices and by dramatically putting up their postal charges. In Australia, our postal authority was smarter - they reacted to the big loss of letter income by:-
a) converting local post offices into stationary, office supply, and trinket stores, as well as traditional postage functions. With the broader product range they can keep them all open.
b) taking a longer time to deliver
c) acting as a one-stop-shop to pay bills.
Canada Post realized they needed to stay relevant. They expanded their parcel services. They deliver most Amazon orders, and all the junk mail you can ask for. They also raised their rates, but I can send a 30g letter 6000 kms for $1.05CAD. We can't compete with countries that subsidize their postal services. I can either pay $3 for 5 resistors from Canada and get them in 2 days, or I can pay $3 for 200 resistors from China, and get them in a month. If you want it traceable, forget it. $10 to send something to the Czech Republic, $70 if I want it traceable! Meanwhile the same package coming to Canada from Czech costs me $15 and it's registered!
Interesting. Here in Australia, you pay $1.10 for a letter (that's about 70 cents American) to go practically anywhere in the country in about 2-3 days (but it used to be overnight).
Anything from China via China Post and Australia Post takes 2 weeks. But tracking by China Post shows most of the delay is after it gets to the Australian airport. I squawked to Australia Post and they told me China Post tracking is lying to me - but I wonder. Parcels sent from one side of Australia to the other take anywhere from 3 to 5 weeks.
Unlike other countries, tracking of parcels from the USA via US Post and Australia Post usually fails completely once it has been flown to Australia. An Australia Post manager told me that is because tracking is by use of a coding system agreed internationally by an association of postal authorities called the International Postal Union - but the US Post Office does not conform to the IPU standard.
That figures - if there is an internationally agreed way to do something, or an international (ISO) standard, the USA is sure to claim it is anti-competitive or something and go their own way. Yet another reason why America, which used to be the source of anything great, has become uncompetitive - and Trump has no idea what's wrong.
Anything from China via China Post and Australia Post takes 2 weeks. But tracking by China Post shows most of the delay is after it gets to the Australian airport. I squawked to Australia Post and they told me China Post tracking is lying to me - but I wonder. Parcels sent from one side of Australia to the other take anywhere from 3 to 5 weeks.
Unlike other countries, tracking of parcels from the USA via US Post and Australia Post usually fails completely once it has been flown to Australia. An Australia Post manager told me that is because tracking is by use of a coding system agreed internationally by an association of postal authorities called the International Postal Union - but the US Post Office does not conform to the IPU standard.
That figures - if there is an internationally agreed way to do something, or an international (ISO) standard, the USA is sure to claim it is anti-competitive or something and go their own way. Yet another reason why America, which used to be the source of anything great, has become uncompetitive - and Trump has no idea what's wrong.
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China doesn’t need to subsidize it’s postal services. The Universal Postal Union (UPU), which is a United Nations agency, has decided, in its infinite wisdom, that China is a poor underdeveloped country and thus entitled to large discounts on its postal rates. The postal services in the West foot the bill to the tune of hundreds of millions of dollars. Strange that Donald Trump hasn’t cottoned on to this yet.
I spent 41 years at Motorola in Plantation Florida. Our plants probably funded a similar sized factory at HP somewhere. There were several production lines and about 1000 engineers in its heydey.....At least 80% of the test equipment was HP.
I am currently recreating the RF workbench that I had at Motorola in 2014 by buying old HP stuff cheap and fixing it. I have good bit of it done, including a lot of stuff that cost big bucks in the 80's. HP 8664 generators, I have 4 working. 1 each working HP 8753C, Agilent 4352B, Agilent E4406A.......
Forum member rsavas worked in the Motorola Toronto facility.
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