[Elecraft] Powerpole police here....

[Mark Petiford]

Re:  "Are they REALLY   0.137795 inches or is 3.5mm just a rounded off way to describe the same physical part using two 
different measurement standards?"

Charlie,

Not sure you are going to get a real definitive answer, but I now believe the 1/8" designation is just a rounded off way to describe a 3.5mm connector.  I didn't believe that before this thread got going.

I dug out all the old connectors I could find from the very bottom of my junk box and measured them.  All of them measured 3.5mm (0.138") as best I could read on my calipers.  None were below 0.137.  I thought for sure I would find some that were 1/8" (0.125") dia., because I remember buying some of them from the local "exploded television" store that were marked as 1/8" phone plugs.  I think those were all mono, not stereo.  In those days, I didn't have a set of calipers or a micrometer to check them, so I just assumed they were 0.125" dia.  Looks like that assumption was wrong.

Whoever wrote the Wikipedia entry on "3.5mm Plug" agrees that 1/8" is just an approximate description used in some countries, and that they actually measure 3.5mm (0.138") diameter, which agrees with my junk box.  I also did a search of Mouser looking for 1/8" Plugs, and all I came up with was 3.5mm plugs.

My memory still recalls seeing connectors that wouldn't quite fit together correctly, but I don't have any that I can find now...and I have some pretty old junk.  Just ask my wife!  ;-)
        
73
Mark
KE6BB

From: Charlie T, K3ICH<pincon at erols.com>
Sent: ‎Sat, ‎Mar‎ ‎15‎, ‎2014 at ‎09‎:‎35‎ ‎PM
To:  <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] Powerpole police here....

That doesn't answer my question..... Are they REALLY   0.137795 inches or is 
3.5mm just a rounded off way to describe the same physical part using two 
different measurement standards?

73, Charlie k3ICH


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