[Boatanchors] Old resistor values

[Garey Barrell]

The increase in value is often a result of storage in high humidity.   
Some have claimed that baking in an oven to drive out the moisture will 
recover them, but ...

I don't think anyone has made carbon comp resistors for several years.  
Most now are carbon or metal film deposited on a ceramic core or ceramic 
composition.  These are very stable.

73, Garey - K4OAH
Atlanta

Yong Surk Lee wrote:

>Thanks for your reply. So do you think the carbon comp resistors recently
>made are OK? I also have many resistors that I bought about 14 years ago.
>These  does not show significant change in values.
>
>----- Original Message ----- 
>From: "Ted Minchin, ZL1MT." <tedm at xtra.co.nz>
>To: <boatanchors at mailman.qth.net>
>Sent: Wednesday, December 15, 2004 11:16 AM
>Subject: Re: [Boatanchors] Old resistor values
>
>
>  
>
>>Yep, I have found that ALL the carbon comp resistors made in the 50's and
>>    
>>
>60's increase resistance with age, used or not.... My view is that they are
>pretty to look at but best not used!!
>  
>
>>73 de Ted
>>ZL1MT
>>
>>    
>>
>>>From: "Yong Surk Lee" <yonglee at yonsei.ac.kr>
>>>Date: 2004/12/15 Wed PM 02:56:31 GMT+13:00
>>>To: <boatanchors at mailman.qth.net>
>>>Subject: [Boatanchors] Old resistor values
>>>
>>>
>>>I found thousands of NOS resistors ranging from 1ohm to a few megohms at
>>>      
>>>
>a
>  
>
>>>local hamfest. I believe these were made by Ohmite in the 50s or 60s.
>>>      
>>>
>These
>  
>
>>>resistors are unused. Strangely measured values of most of these
>>>      
>>>
>resistors
>  
>
>>>are about 10-20% higher than color coded values. Most of these are
>>>      
>>>
>0.25-2
>  
>
>>>watt and 5 or 10% tolerence resistors.
>>>Here is my question. Does the resistor values increase as time passes
>>>      
>>>
>even
>  
>
>>>if unused? Anybody experienced this?
>>>
>>>
>>>
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>>    
>>
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>
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>http://www.w9wze.org    
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>  
>