Evershed's & Vignoles Direct Reading Resistance Box. - UK Vintage Radio Repair and Restoration Discussion Forum

Phil Wood · 19th Sep 2008, 1:51 pm

I know what this does but can anyone tell me anything about it's history?
I haven't seen one of these before so are there still a lot of them about or are they hard to find?
I love the workmanship of the case, the dovetail joints look like they have been done by hand.
It works fine and is quite accurate.
Phil.

Phil G4SPZ · 24th Sep 2008, 6:33 pm

Could it be ex-GPO? I recall seeing these when I was at college in the 1970s. The instructions refer to its use with a Bridge Megger but my memory fails me on that.

russell_w_b · 24th Sep 2008, 6:58 pm

I'll look at my ex-British Steel notes when I get home, but the Bridge-Megger I am familiar with has these direct resistance knobs incorporated (Bridge-Megger Series 2), and a position allocated: 'Bridge', 'Insulation' or 'Varley'. I thing the Bridge-Megger that goes with your unit will also be splendidly manufactured from wood.

The Series 2 (I wonder if your unit is similar?) has the following ranges: divide by 100; divide by 10; 1; multiply by 10; multiply by 100. A constant speed is applied to the handle of the Megger attached to the resistance to be measured, and the knobs on the direct resistance unit are adjusted until the pointer 'nulls out' at the Infinity mark. The resistance in question can then be read directly off the windows above the knobs. The range selector shifts the decimal point along accordingly.

russell_w_b · 24th Sep 2008, 11:06 pm

Quote:

Originally Posted by russell_w_b

I'll look at my ex-British Steel notes when I get home...

Attached is a copy of some Evershed and Vignoles guff I got when I was serving my time at British Steel, Workington, in 1977. I apologise for the quality, but it clearly shows your resistance box (for use with a Series 1 Bridge-Megger).

You may find it of use.

19th Sep 2008, 1:51 pm	#1
Phil Wood Retired Dormant Member Join Date: Sep 2008 Location: Wirral, Merseyside, UK. Posts: 6	Evershed's & Vignoles Direct Reading Resistance Box. I know what this does but can anyone tell me anything about it's history? I haven't seen one of these before so are there still a lot of them about or are they hard to find? I love the workmanship of the case, the dovetail joints look like they have been done by hand. It works fine and is quite accurate. Phil. Attached Thumbnails

24th Sep 2008, 6:33 pm	#2
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Re: Evershed's & Vignoles Direct Reading Resistance Box. Could it be ex-GPO? I recall seeing these when I was at college in the 1970s. The instructions refer to its use with a Bridge Megger but my memory fails me on that. __________________ Phil Optimist [n]: One who is not in possession of the full facts

24th Sep 2008, 6:58 pm	#3
russell_w_b Dekatron Join Date: Jul 2007 Location: Penrith, Cumbria, UK. Posts: 3,687	Re: Evershed's & Vignoles Direct Reading Resistance Box. I'll look at my ex-British Steel notes when I get home, but the Bridge-Megger I am familiar with has these direct resistance knobs incorporated (Bridge-Megger Series 2), and a position allocated: 'Bridge', 'Insulation' or 'Varley'. I thing the Bridge-Megger that goes with your unit will also be splendidly manufactured from wood. The Series 2 (I wonder if your unit is similar?) has the following ranges: divide by 100; divide by 10; 1; multiply by 10; multiply by 100. A constant speed is applied to the handle of the Megger attached to the resistance to be measured, and the knobs on the direct resistance unit are adjusted until the pointer 'nulls out' at the Infinity mark. The resistance in question can then be read directly off the windows above the knobs. The range selector shifts the decimal point along accordingly. __________________ Regds, Russell W. B. G4YLI.