Many products these days are subjected to "Stress Testing" (HALT, HASS,
Shmoo, etc.). This process tests products at both high and low temperatures
(-20C to 70C for example) and vibration. This is sometimes collectively
called "Shake 'n Bake". For Hi-Rel products this is generally done 100%.
However, doing this 100% on a consumer-grade high volume product can be cost
prohibitive in a highly competitive market so it is usually done on a sample
basis.
Reid, K7YX
-----Original Message-----
From: Stuart Rohre [mailto:rohre@arlut.utexas.edu]
Sent: Wednesday, July 24, 2002 12:04 PM
To: Bill Fulling; tentec@contesting.com
Subject: Re: [TenTec] Jupiter Xmit problem
Bill a mike step up transformer, or the active version of the D104 should
drive most anything.
A cold solder joint may not show up bad for years! We in R&D fear them for
they may work until a unit is shaken, rattled, rolled, or baked and cooled
for a long time, (years) then they start to show up. I had such on a
$100,000 tape recorder of 28 tracks. We had it 5 years, and others had it a
few more until it showed the bad joint that NEVER had been soldered, and it
was a whole bus wire going to 14 sockets! Go figure that cold joint.
Luckily, I stumbled upon it while looking for another problem! It had
gotten intermittent, but would self heal with heating cycle of the equipment
use.
Those things happen, and QC may not catch one. Next time, always look at
the solder yourself with a magnifier, and touch up any non shiny, non
filleted joint, and you may save having to send the rig in.
GL and 73,
Stuart K5KVH (That is a reasonable amount to charge for what is a very time
consuming repair to even find the things.)
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