[Boatanchors] Capacitors (sorry!!)

[Carl]

Id be interested in a Sprague TO-6 if you decide to thin the herd. My old 
1941 Solar finally blew the transformer.

Before that I had a homebrew from a real early CQ Magazine, late 40's that 
did the job but I prefer a classic piece of vintage test equipment.

I dont even bother testing paper caps, they are bad...period; yesterday, 
today or tomorrow.  Reforming 30-70 year old electrolytics is for the birds.

However Ive been finding more and more leaky micas in radios and even a few 
NOS in my stock. Its scary thinking about mass failures down the road.

Carl
KM1H



----- Original Message ----- 
From: <bonddaleena at aol.com>
To: <boatanchors at mailman.qth.net>
Sent: Thursday, November 05, 2009 5:52 PM
Subject: [Boatanchors] Capacitors (sorry!!)


> Hi, I do NOT want to start a flame throwing contest, or offend folks
> who insist on original caps, etc. Perhaps EVERYONE already knows what
> follows, I only hope I can help ONE person!
> I wrote the 'apology' in the Subject line because I had the following
> comment (back when caps were being discussed), but for some reason, it
> was never posted..... Anyway.....
>
> Part of my training as an IBM Engineer was in the field of Reliability.
> I noticed years ago that caps had a very high failure rate. This data
> was obtained from several sources, including:
>
> Mil Spec data
> IBM data for products both in manufacturing and in the field
> Actual service data from our competitors
>
> I am adding this thought, ONLY because I see a lot of folks on this and
> a LOT of other Sites stating.. "I tested the suspect cap, and it's OK".
>
> This isn't much of a diagnosis. Believe it or not, I have several dozen
> cap 'testers' here. Some big $ and some 'el Cheapo'. I have 4 that are
> calibrated and traceable to NIST. However, at my 'main' test bench, I
> use one that anyone can put together for cheap.
>
> HOWEVER, (and I cannot stress this enough!!!). Unless you are testing a
> cap at rated voltage, you ain't learn' much.
>
> For example: I have a 'state of the art', calibrated LCR bridge. BIG $.
> Runs on a 9 V battery. I can grab a cracked "Black Beauty' of say....
> .01 uf / 600V rating and the bridge will measure EXACTLY (.01 uf). Same
> for the .1 ufs, etc. OK, now test it on one of my many testers that
> measures at 'rated' voltage', like a Sprague TO-6A (I have several), or
> a Boonton Lab Bridge, they will 'leak' 500+ volts of the 600VDC applied.
> Yes, I know, that a simple cathode bypass cap, is not going to upset
> the circuit, but think of a coupling cap from the plate of one tube to
> the grid of the next.... you get my drift.
>
> I have SO many pieces of test equipment, that I will be selling most of
> it in the near future. Don't need them. Redundant.
>
> If anyone is interested, I can describe a VERY simple test methodology
> with simple pieces of gear, that I have used for years and hardly ever
> go to the
> 'good' equipment.
>
> Ray at ER Magazine has asked me to write a two part article on this
> subject and also on the dreaded ESR aspect of caps.
> If you would like to know how to use simple test gear for this
> function, please e-mail directly:
>
> n4ue at arrl.net
> or
> bonddaleena at aol.com
>
> Asbestos suit being donned!
>
> ron
> N4UE
> ______________________________________________________________
> Boatanchors mailing list
> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Boatanchors at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html