Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Cursitor Doom Newsgroups: sci.electronics.design Subject: Re: Favourite Test Equipment Date: Mon, 01 Apr 2024 18:33:20 +0100 Organization: A noiseless patient Spider Lines: 66 Message-ID: References: <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com> <1qrchq1.w6xc5sp9kef4N%liz@poppyrecords.invalid.invalid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Injection-Date: Mon, 01 Apr 2024 17:33:22 +0200 (CEST) Injection-Info: dont-email.me; posting-host="6abd7acbea44dc0d341b8a0e36c8afda"; logging-data="2762823"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+LaiVQLm2xaBSEP1F0fUiTLIOLAxHlhzM=" User-Agent: ForteAgent/8.00.32.1272 Cancel-Lock: sha1:M4j0ryF/UzC0g1ZhzYxdhYvJTNI= Bytes: 4600 On Mon, 1 Apr 2024 17:34:24 +0100, liz@poppyrecords.invalid.invalid (Liz Tuddenham) wrote: >Jan Panteltje wrote: > >> I learned the basics of how electrons behave and move as a small kid from >>this book: [...] > I remember walking the streets of Amsterdam looking >>for usable parts for my own TV in primary school > >Jan, you forget that we had the *advantage* of starting from the >beginning and having to make or scrounge everything. > >When I started, there was nobody with much knowledge of electronics to >help me and very little material of any kind. My city had been bombed >during WWII (not as bad as Amsterdam, but bad, nevertheless) and both my >grandfathers showed us how to make furniture from odd scraps of wood. >The family motto seemed to be "If you can't make it, you can't have it". > >I eventually learned to solder with a gigantic 65-watt iron that could >undo two tags of an octal valveholder while you tried to solder the >third. I saved my pocket money for a year to buy a government surplus >multimeter - and when it arrived, the pointer was lopsided and the >safety cutout had been glued solid. There was no "Sale of Goods Act", I >just had to take it apart and mend it myself. > >I begged scrap radio and television sets off a local repair shop to use >as a source of components - you made what you could with whatever you >had to hand. Government surplus valves were available but expensive; >you just had to hope they were not too low on emission, because nobody >had any way of testing them. Amplifiers were 'designed' by rote: the >anode load resistor of a 6J7 was 47k - or 100k - nobody knew why. A 6V6 >needed a transformer to match it to the loudspeaker - any transformer, - >nobody knew how to calculate ratios and it wouldn't have mattered if >they had, because the chances of finding the correct transformer were >nil. Data sheets were a closely-guarded secret, I never even saw one >until I went to college. > >My first oscilloscope was an EMI WM2 (partly designed by Alan Blumlein, >I believe). It was absolutely lethal to work on and most of the >components were out of specification or intermittent, so It only worked >for brief periods between long intervals of failure and repair. > >When I took the job of setting up an electronics workshop for an >educational establishment, we could afford a 12v soldering iron but no >transformer, so I begged a scrap pre-war one off my cousin's business. >I set about building a stabilised power supply around it, but it had to >be switched off each time I wanted to make a soldered joint, so I had to >be quick and finish each connection before the iron cooled down. We had >no large resistors, so I loaded the power supply on test with a plastic >bowl full of salty water and a couple of pieces of aluminium plate. > >Many of the huge 'boat anchors' of test gear, so despised by the modern >generation are still working and still perfectly adequate ...as long >as you know what you are doing. Yes, and more importantly, they can be *kept working* indefinitely because although they do blow up quite frequently, they're also pre-SMT, so even people with my shaky hands and poor eyesight can repair them. Thank god for through-hole! Your comment on the soldering iron reminded me of my first one which had to be heated up with a blowlamp. I managed to find one on Ebay for illustration: https://tinyurl.com/kbanemun