My resistor question(s) thread.

[AnalogKid]

Older 5% and 10% (even 20%) resistors were easy to red, had good bright colours and a nice contrasting background

I miss me some carbon comp.

ak

 

[Nigel Goodwin]

I miss me some carbon comp.

ak

How did you used to red the OLD resistors, wasn't it body, spot, tip or something like that? - only three colours, as they were 20% tolerance.

 

[Pommie]

How did you used to red the OLD resistors, wasn't it body, spot, tip or something like that?

Wow, I'm 63 and don't remember anything like that. I remember when there were only 3 transistors (I think) red spot, yellow spot and green spot. And then came the OC71.

Mike.

 

[Nigel Goodwin]

Wow, I'm 63 and don't remember anything like that. I remember when there were only 3 transistors (I think) red spot, yellow spot and green spot. And then came the OC71.

Mike.

I'm 66, and those style of resistors pre-dated the coloured stripe ones - bit before my time, but I repaired plenty of gear that used them, and we even had some in (old) stock

 

[Pommie]

Having never worked in the Electronics industry but high voltage switchgear instead, I guess I never came across them.
My dad worked for Radio Rentals and got me various bits when I was a kid. I think I had a schematic that needed a red spot transistor and the technician at RR said an OC71 would do.

This thread has turned into a rabbit hole. Sorry, OP.

Mike.

 

[Les Jones]

I have found one of those old style resistors in my junk.

This reads 56 ohms (Green 5, Blue 6, Black decimal multiplier 0) It actually measures 50 ohms.
The spot was sometimes a band in the middle of the resistor.
I remember them when I was a child removing them from WW2 surplus equipment as that was my only source of components. We has quite a few WW2 surplus shops in Liverpool at the time. Super radio, Beaver radio, Miligans and Bensons.

Les

 

[Pommie]

Wow, Les, never seen that before. Quiet an interesting example, this thread has certainly been nostalgic.

Mike.

 

[Nigel Goodwin]

I have found one of those old style resistors in my junk.
View attachment 136365
This reads 56 ohms (Green 5, Blue 6, Black decimal multiplier 0) It actually measures 50 ohms.
The spot was sometimes a band in the middle of the resistor.
I remember them when I was a child removing them from WW2 surplus equipment as that was my only source of components. We has quite a few WW2 surplus shops in Liverpool at the time. Super radio, Beaver radio, Miligans and Bensons.

Les

I was close then, that would make it body, tip, spot Not bad from memory.

Where I used to live there was a tip on the edge of the moor, and as a kid I used to get all my parts out of old TV's and Radios that were thrown away (I had no money to buy components, or anything else).

We spent loads of time at the tip, making bikes out of parts we found, making soap box carts out of wheels we found - usually lot's of wheels, and 5 or 6 kids on it, going down the road which was a 1 in 6 hill! (no body died, don't know how not).

 

[danadak]

Regards, Dana.

 

[MDC]

I need to study these a bit. Are they 'old style' ?

 

[JimB]

Are they 'old style' ?

I would call it "Industrial Archaeology".

All very interesting, but you are unlikely to see it very often.

JimB

 

[Nigel Goodwin]

I need to study these a bit. Are they 'old style' ?

VERY old style, no point in studying them unless you like playing with seriously old electronics - think probably pre-WWII.

As far as I'm aware they disappeared from use long before transistors appeared on the scene.

I suppose the only thing to 'study' is the order you read the colours in, as the colour code is still the same.

 

[danadak]

There is a significant activity in the Amateur radio groups restoring old radios,
receivers, transceivers, transmitters, so the charts well used. Most of these R's
age going out of spec high, shorted, or open.

Range of Radios largely 1930's thru ~mid 50's.;


Regards, Dana.

 

[Nigel Goodwin]

There is a significant activity in the Amateur radio groups restoring old radios,
receivers, transceivers, transmitters, so the charts well used. Most of these R's
age going out of spec high, shorted, or open.

Range of Radios largely 1930's thru ~mid 50's.;


Regards, Dana.

Shorted would be VERY rare, some specific values of old carbon resistors (not as old as the body/tip/spot type) do go low value though, as I recall it was usually 39K or 47K?. I've always presumed it was due to the heat dissipated?, and was common among various different valve items, makes and models.

Historically 47K was always the most used resistor in TV servicing

 

[MDC]

Fig No 3 The yellow 47ohms resistor is portrayed differently to the others, almost like it is flexible or part of a cable?

 

[Pommie]

In case anyone hasn't noticed, the majority of the resistor colour code is the ROY G BIV (Richard Of York etc.) rainbow colours - with indigo missing due to being too close to violet. So you might know most of it already. Add in black and white as lowest and highest and only two left to learn.

Mike.

 

[gary350]

Resistors are not easy to read these days I find goofy colors like pink. What is pink, RED? Yesterday I found a resistor with yellow on both ends??? Is Turquoise color green or blue? Buy an LDR meter. Keep resistor ribbons marked and in order. Most resistors these days are 1%. Test everything before you use it to make sure you know what you have.

 

[unclejed613]

danadak
I've seen the tolerance figures, but not seen the letters A to D etc in brackets - end column before. I wonder what those letters represent?

the letters are used when the value is printed on the part. so a 1001F would be a 1K 1% tolerance resistor, 242K would be a 2.4K 10% tolerance resistor, and would be 5% tolerance if the letter was J instead (242J)