History

Used my 6" slide rule last night - although to be fair as a ruler not a calculator. Used brand new French Curves at the weekend to draw a template for a guitar stand. I must admit my AVO8 and AVO7 have been gathering dust, but I have got a little project on where it's going to be a darn sight easier to see what's going on with an analogue scale rather than a load of numbers jumping around so might be about to get one of them out.


That said, in the day job I never see any of the above...

P.S. "Grandad's multimeter" looks remarkably like my dad's multimeter (I think it's still in a cupboard somewhere in my mum's house?) He did buy himself a nice new one in the 1960s to replace it but to my shame I blew that one up quite spectacularly in my early experiments - I did buy him a replacement as soon as I was earning!

I still have my dad's 12" slide rule, plus one I bought myself to tide me over at college when my calculator was being repaired under warranty and a further 6" slide rule I inherited in a shed when I bought a house. I don't use them very often, but still can. Just in case, I also have my great-uncle's copy of "The Slide Rule - a Practical Manual" which he bought in April 1921 and has details of how to do some quite complex calculations such as with the slide inverted.

A moving coil meter has many advantages over a digital multi meter in some instances.


Z.

We still used AVO 8 meters at university only around 12 years ago. They didn't look as old as the one in your picture though.

I do have a fairly new Fluke but my meter of choice is this old BBC unit. It is compact easy to read and has a 15A range. 10A is usual on most instruments. Unfortunately after some 35 years the movement is starting to have problems so I will have to decide if I want to splash out on its replacement model.

Hi Everyone,


My first time accessing this site.  Don't know what I'm doing actually.


But just to chip in about slide rules.  I still have my old one plus my Dad's.  This was a Hemmi - considered the cat's whiskers back in the old days.  Even now, when I squint along it it's as straight as a die.


Since this is the History department, I would like to see if anyone can help me with a bit of research into my Dad's career.  He worked for Standard Telephones and Cables (STC) back in the 1930s and 40s.  He took lots and lots of photographs of some of his field trips in England, Scotland and China.  They are beautiful pictures but he didn't write anything on the back of them.  They seem to be of the installation of cable systems in each of those countries before the second world war.  I cannot find any details of them.  I bought a book about the history of STC and it didn't help.   Anyone have any ideas about how I might proceed?


Regards


John Barkwith

Hello John,


I would suggest that you post a few examples from the UK, especially if they show buildings, some people on here may be able to identify the locations.


Here are a few more old pictures, firstly from a 1935 GEC catalogue and then from a 1905 book on electric motors.

I have an AVO model 40, still in occasional use. I was interested in Robert Bryant's collection, and particularly his dad's improvised battery holder as an alternative to the special type supplied for these instruments. For mine, I took the easier way out and purchased a battery holder from Maplin, to take a common cell size U11 (alias LR14, alias MN1400, alias C - why do these designations bear no relation to physical dimensions?).


I've shown this picture before but I'll show it again.
























I spotted this collection, all now obsolete, at the Amberley museum, near Arundel. At the top left of the pile there is a type R1662 cell, with screw terminal and free wire, as used in AVOs. Many portable radios of that era used two batteries, one at 1½ V and one at 90 V (which could certainly give you a shock). Towards top right is a type 800 "twin cylinder" cycle lamp battery, very common in bicycle lamps in the '50s and into the '60s.


The Ever Ready brand dominated the battery market in those days. After successive reorganisations it has become Energiser, though the Ever Ready stamp still appears on odd occasions.


Drydex was a brand name used by Exide for its dry battery range.


Another popular brand name of those days was Vidor. It was subsequently absorbed into Crompton Parkinson, but has now disappeared from the market place.