[Milsurplus] Postmortem on DEF headphone elements

[Robert P. Meadows]

I am confused, what is a DEF headphone??  The only DEF I am aware of is
Diesel Exhaust Fluid.

Please someone explain, have I missed something?

R

 

From: milsurplus-bounces at mailman.qth.net
<milsurplus-bounces at mailman.qth.net> On Behalf Of Hubert Miller
Sent: Friday, August 9, 2019 12:57 PM
To: milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] Postmortem on DEF headphone elements

 

Ramon Vargas Patron, a university professor in Lima, Peru, a friend of mine,
reminded me that these were high impedance elements and to be sure of my
measurements.

I rechecked them. 

I found ONE with very unusually low resistance. I rechecked the rest and I
see I had the tables turned, ONE of eight was defective, not other way
around ! Still a higher fail rate than 

mil-spec, but not a disaster. I am now puzzled how a low resistance short
could occur.

I think my mistake would have been less likely had I been using an old
moving - pointer analog VOM. 

En ingles, llamamos este un caso de "egg on face".  ( = embarrassment ) 
This is why we need degreed engineers around: to check our work, keep us
honest. 

-Hue 

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