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ID Potentiometer

bushtech

Sep 13, 2016
1,025
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Sep 13, 2016
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I've got this nice old 10 turn pot. Unfortunately all the stickers have just about disintegrated from old age and I know nothing about it and it's history. Just for interest it was made by Beckman Instruments in Glenrothes Fife Scotland. Model RD. I'm hoping kellys eye will know them intimately;)

What I would like to know is this a 10k, 100k or what? A clue might be the 150Ω resistor on the one leg. How do I ID this baby?
side2.jpg

front2.jpg
 

shrtrnd

Jan 15, 2010
3,876
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Jan 15, 2010
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3,876
What Externet means, is that you can take an ohmmeter reading across the bottom lead and the top lead (the center lead is the wiper for variable resistance), and you will have the value of the pot in ohms.
 

bushtech

Sep 13, 2016
1,025
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Sep 13, 2016
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Thanks externet and shrtnd. My confusion stemmed from the fact that I was getting 25Ω and I didn't know you got 25Ω pots. Brain was expecting something in the k range. Still trying to find one on the web
 

73's de Edd

Aug 21, 2015
3,613
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Aug 21, 2015
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3,613
Herr Bushmeister . . . . .

Ahhhhhhhhh yes . . . . ve chust bin gettink in a fresh shipments in dis morninks . . .und vud you
be vantink der model vit dere left hands or right hands knob ?

Toto . . .they are not $5.00 anymore . . . . alas . .

Also that counter dial / knob adds ooooooodles onto the price also.. .

https://www.elliottelectronicsupply...-precision-potentiometer-beckman-model-a.html

(Beckman Helipot) . . .25 ohms . . . no less . . . .


73's de Edd
 

bushtech

Sep 13, 2016
1,025
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Sep 13, 2016
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Thanks st. Edd. Our power going out has put paid to my googling. But thats NOS. Do you still get something like that today?
 

kellys_eye

Jun 25, 2010
6,514
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Jun 25, 2010
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10 turn pots can be had all over the place these days but getting a QUALITY 10-turn pot isn't cheap. Such as you have there is worth keeping hold of.

Not all 10-turns have the full resistance across top/bottom connections. Measure all combinations of terminal and the HIGHEST reading will be the pot value.

The turns-counting dials are also readily available these days too - not a lot of value in them. I recently scrapped a multi-stage variable PSU (kV range) that had four multi-turn pots with turns-counting dials but the pots were all cheap and nasty - open circuit - but the dials were still salvageable.
 
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