reading old resistors

T

technokid

Member
Hi,

I was going through my resistors to sort them and came across these:

SDC10154.JPG

I don't remember how to read these old resistors, which side is which, or even the difference between these and the new resistors.
I hope that anyone remembers these and can help me tell the values.
I hope that these are read the same as resistors today.
Please help.

Thanks,
Technokid
 
premelec

premelec

Senior Member
360+00 = 36K assuming blue rather than violet... pretty funny you thing these are OLD! I was thinking you might have some of the carbon bars with wire wrapped around each end and dot color :) I'm old...
 
D

Dippy

Moderator
Orange/Blue/Black +Red tolerance.
I assume there are no other markings? The photo is (politely) lacking in quality.
I'd agree with Steve G.
Just get your multimeter on them to confirm... far quicker than posting here surely?

Actually, with hindsight, I'm beginning to wonder... multimeter time. And then write the value on the bandolier paper.
 
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G

Goeytex

Senior Member
It is is a 4 band resistor it is 36 ohms @2%. IF there is another band (silver?) that the photo does not reveal then it is 36K. The ohmmeter will reveal the real answer.
 
premelec

premelec

Senior Member
Or put one across a 12 v car battery and see what happens... :)

See original hand painted resistors pic attached - probably 70+ years old...
 

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erco

erco

Senior Member
Simple enough to measure, technokid. If you want to burn some forum brainpower, ask how to read a long-before-you-were-born capacitor. :)



More at http://www.wjoe.com/capacitorinfo.htm

And on the subject of vintage electronics, here's a question for anyone under 25 years old. What's the name of this first-generation breadboard connector?

 
D

Dippy

Moderator
Premelec, my Dad had a manufacturer's display board with some of those old resistors.
Weren't they read Body-End-Dot? (BED)
In those days you'd double-check with an Avometer Mk2... mmm.
 
A

AllyCat

Senior Member
Hi Steve,
sghioto said:
36 ohm 2%
Click to expand...
Is that the answer, or just your selection of the "best guess" so far? How did the multimeter "prove" it is a 2% tolerance ?

It might / could have a 5th brown band (i.e. the same colour as the body) as is normally required for 1% or 2% resolution values? That would read 3-6-0-2-1 , i.e. 1% tolerance, and 36 kohms, as suggested in #3. Or it could be a "3602" axial inductor (which can look very similar) with almost zero resistance!

Cheers, Alan.
 
D

Dippy

Moderator
Just think Alan, tolerance aside, it would take the OP less time to measure than thee or me to write a post :)
A number of people have provided a best guess based on the blurry images.

How will a multimeter 'prove' 2% tolerance?
Easy, get 10,000 resistors measure them all and do some stats. That'll give a reasonable real answer.

I see the OP hasn't (at time of typing) logged-in to have a look at any responses... maybe he/she has gone to shop to buy a multimeter?
Most people that are in any doubt will double-check with a meter - this should be fairly obvious.

On another tack, I had to check some values in an old bit of gear which had run hot for years.
The Vishay PR01 resistor colour bands had actually changed colour.
Checked with multimeter.
 
premelec

premelec

Senior Member
@Dippy - Body-End-Dot is correct - and 20% unless there is another end dot [checked in the 1949 Radio Amateur's handbook I have] - the ones I have are a bit off :) - I also have seen color changes with over heating... and notching them to bring the value higher [then sealing with some enamel]. It's interesting that something with the only function of dissipation of energy is ubiquitous - perhaps similar to friction in the mechanical realm - very necessary!
 
S

sghioto

Senior Member
Alan,

To me the resistors in the photo appear to have only four color bands and if that assumption is correct then the value is 36 ohms, 2% tolerance.

How did the multimeter "prove" it is a 2% tolerance ?
Click to expand...
I'm not sure what you are asking here.:confused:

Steve G
 
J

john2051

New Member
Hi Premelec, thanks for the photo. A trip down memory lane for sure. I still have quite a few new resistors of that type. Our local
radio component supplier also still sells these new if you ask. The new resistors with five bands I still have to verify on my dmm.
When I think how components have changed over the fifty years I've been using them. I wish I had access to picaxes in the sixties though,
what would we have now..
regards john
 
premelec

premelec

Senior Member
You mean they are selling painted carbon composition rods? That seems pretty strange! Components have indeed changed a lot and if you drop one it may take hours to find it in the rug :)
 
fernando_g

fernando_g

Senior Member
aaaaaaaaaaaaah Nostalgia!

This reminds me of point to point wiring of 5 tube radios, in steel chassis and bakelite cabinets.

In those days one would use a VOM in ohms mode, zero the reading and measure the resistor while squinting at a non-linear scale, and interpolating between ticks.
DMMs make resistor measuring absolutely trivial.
 
G

geoff07

Senior Member
These days you could use the old resistors as noise generators. Of course, when your valves were running on 250v dc what did a little noise matter?
 
T

technokid

Member
I just tested them with my dads old multimeter. It says that they are 36 ohms.
Dad says that he has only ever seen 33 and 39 ohm resistors. He has never heard of 36 ohms resistors.
This thread really got a debate going, didn't it?
Thanks for all of your help.

Technokid

P.S I haven't had time to check the thread lately as I am more busy building a 3d printed, robot hand. Almost finished :)
 
D

Dippy

Moderator
36Ohm and many other 'in-between' values are available - I daresay some small/old shops will only have a limited range.
Show your Dad this:-
http://uk.farnell.com/te-connectivity/cfr25j36r/resistor-carbon-36r-0-33w-5/dp/2329667

It's merely an example so I don't want to start a competition :)

(I assume you've checked your Dad's old multimeter against some definite known values as a double-check?)

Oh yes, it can really get things going on here; everyone knows best ;)
Entertaining and I'm glad it's sorted.

Don't forget:-
When in doubt , dig your meter out.
 
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