Resistor

[reeltoreelrob]

Hi All,
This is not vintage as such but could anyone give me a bit of advice on this resistor, its a 4 band and is brown, black, gold and black, totaly confused as how to read it! Is it a special type of resistor as there are a few of them in this unit but it is different the the one behind it. I have put 2 pictures in, the one I am testing is the red, red and black I would say that's 22 ohms but it reads 0.06 ohms, it is in line with a motor and has been overheating so maybe that's why its low reading. I only ask about the resistor with a gold band in the middle in case these are a special type.
Thanks in advance,
Rob.

[TonyDuell]

Are you sure it is a resistor and not a small inductor?

[reeltoreelrob]

Hi I am not sure to be honest, I thought it was a resistor untill I saw the one with the gold band in the middle and not the end.

[Stylo N M]

Hi,

1 ohm perhaps? (i think it is a resistor judgeing by the 22 ohm one in the other picture)
if it's inline with a motor, and of poor qualitty, it will of droped in value quite significantly due to heat damage.

It might be better, to replace it with a small wire wound one instead, to maintain it's value during operation, and would cope better in any tempreture change situation.

Paul.

[AC/HL]

Tony's suggestion is most likely, possibly a suppression component. There's no sign of overheating. What is the equipment?

[Biggles]

Looks like a low value inductor to me. I have a few similar in appearance to yours. I think the clue is the larger ends to the component. Of course, it will measure as a resistor, but if you have access to an inductance meter, that would be the sure way to find out.
Alan.

[Stylo N M]

yes you could be right bill, the way i was thinking was, it just looks like an identical shape and size, to that 22 ohm one.

And i've noticed that sometimes, they create silly colour combinations, to indicate just a couple of ohms, that sometimes makes no sense atall in the reading.

But yes tony could be quite right

Paul.

[Terry_VK5TM]

The one with the green body is a 22uH inductor.

The other one looks like 22 ohm 1/2w fusible resistor.
Definitely shouldn't be there if the inductor was the original component.

Terry

[Diabolical Artificer]

The second pic looks like someone has bodged the green bodied R across the leads of the original fused R, which is ok for a quick test but not for a permanent repair.

So doing a bit of detective work, are there any more green/pinched bodied R's on the PCB? If not someone has most likely used them to replace faulty R's. So if there's only two like that on the PCB, the one in pic one could be a one ohm resistor that has failed and gone down in value, though I've found low value R's usually go high in value or OC.

Have you got a schematic? If not can you back engineer one? this would help figure out what should be there. What is it, a 70/80's cassette deck?

Andy.

[ms660]

They look like inductors.

The 1st one, 1uH @ 20%

The 2nd one, 22uH @ 10%

Reasoning: http://www.learnabout-electronics.or...nductors04.php

Lawrence.

[Stylo N M]

Ah yes. Sorry I can see now the other one has got fatter ends, it does look slightly different.

Paul.

[Andrew B]

A Chinese "everything" tester that has been discussed elsewhere on this forum would identify "R" or "L".

[reeltoreelrob]

Hi all,
Thanks for all of the very useful replies!!
The unit is a Philips 720 dictaphone about 5 years old and until now has not been tamped with apart from having to put the belt back on.

The problem was that the motor was not turning and the unit would turn itself off. I noticed the motor control chip was getting very hot and when I checked the (what I thought was a resistor) it had a low resistance reading, so I tacked the grey looking 22k resistor over the inductor and cut the one end of the inductor, the motor then ran ok but the resistor I had temporary put in got very hot but the chip was cool!
I removed the motor and put it on an external supply and it works fine and draws 18ma.
I have got a pack of 22uh inductors on order so I will see what happens.
All the best
Rob.

[AC/HL]

Manual here:https://www.google.co.uk/url?sa=t&rc...,d.ZGg&cad=rja
I'm guessing it's L301, only a Philips part number given in the list.

[reeltoreelrob]

Hi,
Thanks for the diagram, it is the L301 just hope this is the fault as these machines are a fair old price and I would rather be spending the money on another vintage record player or the likes.
All the best
Rob.

[vidjoman]

L301 will either work or not. As it's basically a coil of wire, normally wound on a ferrite core. If you've got a circuit through it then it should be working.

[Amraduk]

Originally Posted by reeltoreelrob

I noticed the motor control chip was getting very hot and when I checked the (what I thought was a resistor) it had a low resistance reading, so I tacked the grey looking 22k resistor over the inductor...

It's 22 OHMS, not 22k!

Regards,

Dave.