[Boatanchors] Old resistor values

[Mark Bell]

I've have also heard the oven claim.  With it comes the statement that the
resistance will start to climb again after the bake, but slowely, and it
will not reach the original (too high) value.

I wonder if you can hollow out the old carbon comps and insert the new metal
film ones, as the film ones are much smaller than their carbon comp
equivalent.

73 Mark K3MSB (Think snow....)




----- Original Message ----- 
From: "Garey Barrell" <k4oah at mindspring.com>
To: "Yong Surk Lee" <yonglee at yonsei.ac.kr>
Cc: <boatanchors at mailman.qth.net>
Sent: Tuesday, December 14, 2004 9:47 PM
Subject: Re: [Boatanchors] Old resistor values


> 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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