[Elecraft] Line Out Jack

[Mark Petiford]

All,

I was involved on this thread very early in its life because I had remembered having a transistor radio that had a mono earphone jack which wouldn't accept a modern 3.5mm plug.  At the time, I thought it was a 1/8 in. jack.  The radio was from Japan and it was made around 1959.  I suggested that I might be able to find one in my junk box.

Well, I went through my entire junk box, as well as a box containing earphones dating back to the 1930's, and found one plug (mono) that had a 2.5mm mono plug on it.  Everything else was 3.5mm. 

Based on all of my searching, I believe that the old transistor radio actually had a 2.5mm jack, and not a .125 inch jack as I thought.  I am also concluding that 3.5mm and 1/8in. plugs are the same thing since I have found no evidence that a .125 inch diameter plug has ever existed.  If anyone finds one, please let us know!

Mark
KE6BB

From: Josh Fiden<josh at voodoolab.com>
Sent: ‎Wed, ‎Apr‎ ‎9‎, ‎2014 at ‎02‎:‎47‎ ‎AM
To:  <elecraft at mailman.qth.net>
Subject: Re: [Elecraft] Line Out Jack

I'm curious about this. If anyone has reference to an actual 1/8" connector, please forward off list. I don't recall them ever being anything but 3.5mm. My recollection is that 3.5mm and 1/8" have always been used interchangeably. I believe (guess) the discrepancy is simply that the plug originated as 3.5mm and 1/8" is the closest fractional inch (9/64 is unsatisfying).Checking specifications from one reputable manufacturer calls out sleeve diameter of 3.5+/-0.05mm for the plug and 3.6mm for the entrance of the jack. As with so many things, I'm sure there's no difficulty finding poorly designed/manufactured Asian parts that deviate.There's no such issue with 1/4" phone connectors. They are called out either as 6.35mm or 6.3mm, which is quite accurate because they originated as the fractional inch dimension.73,Josh W6XUOn 4/7/2014 7:11 PM, Don Wilhelm wrote:> 3.5mm and 1/8 inch are now the same thing - one place calls them 3.5mm > while others use the 1/8
 inch designation for the same thing.>> Yes, it was not always so, but that was well before stereo plugs and > jacks came into existence.> The big issue now is manufacturing tolerances that might mean some > jack and plug combinations are tight while other combinations may > appear to be sloppy.>> 1/4 inch plugs and jacks are more tolerant of sloppy tolerances i.e > +/- 0.01 mm compared to 3.5mm is much greater than +/- 0.01 mm > compared to 7 mm (or is it 8mm?).______________________________________________________________Elecraft mailing listHome: http://mailman.qth.net/mailman/listinfo/elecraftHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Elecraft at mailman.qth.netThis list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.htmlMessage delivered to rv6amark at yahoo.com