Re: Favourite Test Equipment

Jan Panteltje <alien@comet.invalid> 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.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk