(28-07-2011, 11:42 PM)AlanBeckett Wrote: Ah, well, I knew what Col was up to
I've just bought an Avominor in a wooden box. It's beautifully made but a bit old and sad - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=160623968008&ssPageName=STRK:MEWNX:IT
I'll have to put some pictures on and talk to Col.
Alan
Strewth, £1.20 - how jammy was that!!!?
I saved up for weeks in 1960 to buy one, which set me back £10.10.00 (then a week's wages for me), which equates to £150 now. It came in a leather case, complete with prods, and I still have it. (They were black Bakelite back then).
I don't ever recall them being in a wooden box, so I wonder if yours was purpose made by someone - it looks the part.
I spent my career at British Gas - the first ten years 'on the tools' then in service and sales management. Service engineers were provided with a standard tool kit, and when electrical fault finding on central heating and other appliances became a major aspect of their work, the kit included an Avo Multi-Minor. However, they were not very robust or versatile for field work, and the lack of a cut-out to protect them sealed the fate of Multi-Minors before too long. BG later developed their own multimeter which had probes for testing thermocouples, and for checking surface temperatures of radiators and so on.
Service Engineers were trained to do most of their testing by continuity tests with the power off, looking for open circuits or shorts on components such as gas valves, pumps, transformers, wiring, and checking the operation of thermostats. Hence, the Avo Minors were extensively used on the Ohms ranges. However, they also had to do voltage checks, and it's very easy, when tired or under time pressures, to absent-mindedly forget to switch from the Ohms range to the upper AC voltage range, then with no cut-out or any form of protection on the Ohms range. Bang! - the meter was scrap. Few lasted much more than about 3 months.
I don't recall which firm made/makes BG multimeters, but it would be a nice little contract fo them. They stuck with an analogue meter as for testing such things as thermocouples they give a much clearer indicaton than seeing the digits on a digital meter dancing about all over the place. (Just as does peaking tuned stages in a radio).
Different of course if the meter is our own property and used for hobby purposes - we're not under time pressures, unlike field service engineers, going from place to place with a toolkit in which a meter gets buffeted about. Mine is now over 50 years old. Quite a clever design - having a 'landscape' layout rather than 'portrait' the meter scale is nice and large, and the movement is damped too.
Happy days!
David.
