[Boatanchors] Capacitors (sorry!!)

[bonddaleena at aol.com]

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