View Single Post
Old 3rd May 2017, 12:03 am   #8
Phil G4SPZ
Dekatron
 
Phil G4SPZ's Avatar
 
Join Date: Apr 2005
Location: Bewdley, Worcestershire, UK.
Posts: 4,735
Default Re: Avo EA113 electronic multimeter (1971)

Thanks for all the interest, and the kind comments! I was going to paste a picture showing the relative sizes, but David has beaten me to it, and provided lots of other relevant information too. However it's worthwhile to look at the EA113 against the Avo 8 Mk V with its later style of movement. They can't be the same, as the movement in the EA113 is 3.5mA FSD rather than the Avo 8's 37.5uA, but they do look physically similar and I suppose it would have made sense from a manufacturing point of view.

Alistair, yes please, one of those 68 Meg resistors would be ideal, thank you very much for your generous offer. I've PM'ed you with my details.

Philpott, you asked about the speed of response of the pointer, and that's perhaps the major shortcoming of this instrument. My example does respond pretty slowly, about half as fast as an Avo 8 Mk V, so if you're trying to follow rapidly-changing quantities the EA113 would smooth things out rather too well. There's a 10uF tantalum capacitor across the input to the DC amplifier, and I guess this makes everything move rather slowly, including when setting-up the master zero and gain presets.

Having said all that, I agree with Colin that it's a stylish piece of design which is also ergonomically easy to use, probably even easier than the traditional Avometer with its twin range selectors. Mine has made itself at home on the test bench where it has proved useful a couple of times already.

Phil
Attached Thumbnails
Click image for larger version

Name:	Avo EA113 vs Avo 8.jpg
Views:	361
Size:	82.0 KB
ID:	142024  
__________________
Phil

Optimist [n]: One who is not in possession of the full facts

Last edited by Phil G4SPZ; 3rd May 2017 at 12:21 am. Reason: Photo added
Phil G4SPZ is online now